treatments-xml/data/03/DB/87/03DB87FEFFE3062CAF40FBEEFBE68687.xml

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<mods:title id="9C06500E62BF5AC536EBB531A4042C10">Lucinidae (Bivalvia) - the most diverse group of chemosymbiotic molluscs</mods:title>
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<treatment id="03DB87FEFFE3062CAF40FBEEFBE68687" ID-DOI="http://doi.org/10.5281/zenodo.5744207" ID-GBIF-Taxon="190874730" ID-Zenodo-Dep="5744207" LSID="urn:lsid:plazi:treatment:03DB87FEFFE3062CAF40FBEEFBE68687" httpUri="http://treatment.plazi.org/id/03DB87FEFFE3062CAF40FBEEFBE68687" lastPageId="13" lastPageNumber="434" pageId="2" pageNumber="423">
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STATUS OF 
<taxonomicName id="4C724D6BFFE30623AFEEFBEEFD948025" authorityName="J.Fleming" authorityYear="1828" box="[442,624,1037,1061]" class="Bivalvia" family="Lucinoidea" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="435" phylum="Mollusca" rank="family">LUCINOIDEA</taxonomicName>
</heading>
</paragraph>
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<paragraph id="8BCD36E8FFE30623AEDAFBDEFDA88314" blockId="2.[142,758,1085,1904]" pageId="2" pageNumber="423">
Traditionally, the 
<taxonomicName id="4C724D6BFFE30623AF2DFBDEFE0E8053" box="[377,490,1085,1107]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
have been grouped together with the families 
<taxonomicName id="4C724D6BFFE30623AF8EFBB8FDBF8071" box="[474,603,1115,1137]" class="Bivalvia" family="Fimbriidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Fimbriidae</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE30623AC39FBB8FD128071" box="[621,758,1115,1137]" class="Bivalvia" family="Thyasiridae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Thyasiridae</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE30623AE90FB99FEB68090" box="[196,338,1146,1168]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
within the superfamily 
<taxonomicName id="4C724D6BFFE30623AC23FB99FD118090" authorityName="J.Fleming" authorityYear="1828" box="[631,757,1146,1168]" class="Bivalvia" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="superFamily" superFamily="Lucinoidea">Lucinoidea</taxonomicName>
(
<bibRefCitation id="EFE34B19FFE30623AEC2FB7AFEF680AE" author="Dall WH" box="[150,274,1177,1199]" pageId="2" pageNumber="423" pagination="779 - 833" refId="ref8711" refString="Dall WH. 1901. Synopsis of the Lucinacea and of the American species. Proceedings of the United States National Museum 23: 779 - 833." type="journal article" year="1901">Dall, 1901</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AF75FB7AFE5080AE" author="Thiele EKHJ" box="[289,436,1177,1199]" pageId="2" pageNumber="423" refId="ref10624" refString="Thiele EKHJ. 1934. Handbuch der Systematischen Weichtierkunde 2 (3). Jena: Fischer." type="book" year="1934">Thiele, 1934</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AF90FB7AFD8380AF" author="Chavan A" box="[452,615,1177,1199]" pageId="2" pageNumber="423" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan, 1969</bibRefCitation>
), largely on the basis of similarity of shells and some anatomical features. Chemosymbiosis in 
<taxonomicName id="4C724D6BFFE30623AC55FB35FD9680EC" box="[513,626,1238,1260]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
was first reported in the early 1980s (
<bibRefCitation id="EFE34B19FFE30623AFBAFB16FD16810A" author="Berg CJ &amp; Alatalo P" box="[494,754,1269,1291]" pageId="2" pageNumber="423" pagination="165 - 179" refId="ref8131" refString="Berg CJ, Alatalo P. 1984. Potential of chemosymbiosis in molluscan mariculture. Aquaculture 39: 165 - 179." type="journal article" year="1984">Berg &amp; Alatalo, 1984</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AEDAFAF0FE648129" author="Reid RGB &amp; Brand DG" box="[142,384,1299,1321]" pageId="2" pageNumber="423" pagination="3 - 24" refId="ref10117" refString="Reid RGB, Brand DG. 1986. Sulfide-oxidising symbiosis in lucinaceans: implications for bivalve evolution. Veliger 29: 3 - 24." type="journal article" year="1986">Reid &amp; Brand, 1986</bibRefCitation>
) and subsequently 
<taxonomicName id="4C724D6BFFE30623AC39FAF0FD128129" box="[621,758,1299,1321]" class="Bivalvia" family="Thyasiridae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Thyasiridae</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE30623AE95FAD1FEA48148" box="[193,320,1330,1352]" class="Bivalvia" family="Fimbriidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Fimbriidae</taxonomicName>
were shown to have some chemosymbiotic species (
<bibRefCitation id="EFE34B19FFE30623AF67FAB2FD828167" author="Dando PR &amp; Southward AJ &amp; Southward EC" box="[307,614,1361,1383]" pageId="2" pageNumber="423" pagination="227 - 247" refId="ref8772" refString="Dando PR, Southward AJ, Southward EC. 1986. Chemoautotrophic symbionts in the gills of the bivalve mollusc Lucinoma borealis and the sediment chemistry of its habitat. Proceedings of the Royal Society of London B 227: 227 - 247." type="journal article" year="1986">Dando &amp; Southward, 1986</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AC25FAB2FF238185" author="Southward EC" pageId="2" pageNumber="423" pagination="889 - 914" refId="ref10261" refString="Southward EC. 1986. Gill symbionts in thyasirids and other bivalve molluscs. Journal of the Marine Biology Association of the United Kingdom 66: 889 - 914." type="journal article" year="1986">Southward, 1986</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AE8CFA93FE648185" author="Janssen HH" box="[216,384,1391,1413]" pageId="2" pageNumber="423" pagination="5 - 32" refId="ref9546" refString="Janssen HH. 1992. Philippine bivalves and microorganisms: past research. present progress and a perspective for aquaculture. Philippine Scientist 29: 5 - 32." type="journal article" year="1992">Janssen, 1992</bibRefCitation>
), but no chemosymbionts have been reported from any 
<taxonomicName id="4C724D6BFFE30623AF99FA6DFDBA81A4" box="[461,606,1422,1444]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
. Also, often included within the 
<taxonomicName id="4C724D6BFFE30623AF2CFA4EFE1281C3" authorityName="J.Fleming" authorityYear="1828" box="[376,502,1453,1475]" class="Bivalvia" family="Lucinoidea" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="435" phylum="Mollusca" rank="family">Lucinoidea</taxonomicName>
are the poorly known brackish water family 
<taxonomicName id="4C724D6BFFE30623AFC4FA28FDCC81E1" authorityName="H.Adams &amp; A.Adams" authorityYear="1857" box="[400,552,1483,1505]" class="Bivalvia" family="Cyrenoididae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Cyrenoididae</taxonomicName>
and the Mesozoic and Palaeozoic fossil groups 
<taxonomicName id="4C724D6BFFE30623AFBCFA09FD6B8200" authorityName="Cox" authorityYear="1929" box="[488,655,1514,1536]" class="Bivalvia" family="Mactromyidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Mactromyidae</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE30623ACCBFA09FF36821F" authorityName="P.A.Johnston" authorityYear="1993" class="Bivalvia" family="Paracyclidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Paracyclidae</taxonomicName>
, and 
<taxonomicName id="4C724D6BFFE30623AF4AF9EAFE45821F" authorityName="Horny" authorityYear="1960" box="[286,417,1545,1567]" class="Bivalvia" family="Babinkidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Babinkidae</taxonomicName>
(
<bibRefCitation id="EFE34B19FFE30623AFE2F9EAFDB9821F" author="Chavan A" box="[438,605,1545,1567]" pageId="2" pageNumber="423" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan, 1969</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AC3BF9EAFD16821E" author="Boss KJ" box="[623,754,1545,1566]" pageId="2" pageNumber="423" pagination="945 - 1166" refId="ref8261" refString="Boss KJ. 1982. Mollusca. In: Parker SP, ed. Synopsis and Classification of Living Organisms. New York: McGraw-Hill, 945 - 1166." type="book chapter" year="1982">Boss, 1982</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AEDAF9C4FEAC823C" author="Johnston PA" box="[142,328,1575,1597]" pageId="2" pageNumber="423" pagination="1 - 134" refId="ref9609" refString="Johnston PA. 1993. Lower Devonian Pelecypoda from southeastern Australia. Memoirs of the Association of Australasian Palaeontologists 14: 1 - 134." type="journal article" year="1993">Johnston, 1993</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AF0BF9C4FD70823C" author="Skelton PW &amp; Benton MJ" box="[351,660,1575,1597]" pageId="2" pageNumber="423" pagination="237 - 263" refId="ref10223" refString="Skelton PW, Benton MJ. 1993. Mollusca: Rostroconchia, Scaphopoda and Bivalvia. In: Benton MJ, ed. The Fossil Record 2. London: Chapman &amp; Hall, 237 - 263." type="book chapter" year="1993">Skelton &amp; Benton, 1993</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623ACFEF9C4FF2C825C" author="Amler MRW" pageId="2" pageNumber="423" pagination="237 - 248" refId="ref8021" refString="Amler MRW. 1999. Synoptical classification of fossil and Recent Bivalvia. Geologica et Palaeontologica 33: 237 - 248." type="journal article" year="1999">Amler, 1999</bibRefCitation>
). Species of the Recent genus 
<taxonomicName id="4C724D6BFFE30623AC7AF9A5FD51825B" authorityName="Iredale" authorityYear="1930" box="[558,693,1606,1627]" class="Bivalvia" family="Lucinidae" genus="Bathycorbis" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE30623AC7AF9A5FD51825B" box="[558,693,1606,1627]" italics="true" pageId="2" pageNumber="423">Bathycorbis</emphasis>
</taxonomicName>
have been claimed as living representatives of the 
<taxonomicName id="4C724D6BFFE30623ACE8F986FEE68299" authorityName="Cox" authorityYear="1929" class="Bivalvia" family="Mactromyidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Mactromyidae</taxonomicName>
(otherwise with no post-Cretaceous records) on the basis of supposed similarities of hinge teeth (
<bibRefCitation id="EFE34B19FFE30623AE8DF922FE9E82D7" author="Chavan A" box="[217,378,1729,1751]" pageId="2" pageNumber="423" pagination="509 - 512" refId="ref8552" refString="Chavan A. 1959. Essai critique de classification des Mactromyidae. Cahiers Geologique 52: 505 - 508, 53: 509 - 512." type="journal article" year="1959">Chavan, 1959</bibRefCitation>
, 
<bibRefCitation id="EFE34B19FFE30623AFD3F922FE2582D7" author="Chavan A" box="[391,449,1729,1751]" pageId="2" pageNumber="423" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">1969</bibRefCitation>
). However, the affinities of these small (
<emphasis id="B906EAFAFFE30623AF4AF903FECD82F5" box="[286,297,1760,1781]" italics="true" pageId="2" pageNumber="423">c</emphasis>
. 
<quantity id="4C8A9B0DFFE30623AF61F93CFE9382F5" box="[309,375,1759,1781]" metricMagnitude="-3" metricUnit="m" metricValue="5.0" pageId="2" pageNumber="423" unit="mm" value="5.0">5 mm</quantity>
) offshore bivalves from 
<collectingCountry id="F3657678FFE30623ACD7F93CFD1582F5" box="[643,753,1759,1781]" name="Australia" pageId="2" pageNumber="423">Australia</collectingCountry>
, known only from shells, are uncertain.
</paragraph>
<paragraph id="8BCD36E8FFE30623AEF3F8FEFB5B87B9" blockId="2.[142,758,1085,1904]" lastBlockId="2.[806,1423,195,953]" pageId="2" pageNumber="423">
Most discussions of relationships within the 
<taxonomicName id="4C724D6BFFE30623ACCAF8FEFF5A8351" authorityName="J.Fleming" authorityYear="1828" class="Bivalvia" family="Lucinoidea" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="435" phylum="Mollusca" rank="family">Lucinoidea</taxonomicName>
have concerned only the families 
<taxonomicName id="4C724D6BFFE30623AC29F8D8FD168351" box="[637,754,1851,1873]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE30623AEDAF8B9FEFC8370" box="[142,280,1882,1904]" class="Bivalvia" family="Thyasiridae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Thyasiridae</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE30623AF7EF8B9FE5C8370" box="[298,440,1882,1904]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE30623AFA9F8B9FD9A8370" box="[509,638,1882,1904]" class="Bivalvia" family="Fimbriidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Fimbriidae</taxonomicName>
, with the tacit assumption that they form a monophyletic group. Several scenarios have been proposed that attempt to place the 
<taxonomicName id="4C724D6BFFE30623ADF7FEE2FBF28517" box="[931,1046,257,279]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE30623AA7CFEE2FB568517" box="[1064,1202,257,279]" class="Bivalvia" family="Thyasiridae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Thyasiridae</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE30623AA92FEE2FAB08517" box="[1222,1364,257,279]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
and sometimes 
<taxonomicName id="4C724D6BFFE30623ADF3FEFCFBC28535" box="[935,1062,287,309]" class="Bivalvia" family="Fimbriidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Fimbriidae</taxonomicName>
into an evolutionary sequence. There have been major differences between each of these, relating to either anatomical characters, or time of first appearance in the fossil record (
<bibRefCitation id="EFE34B19FFE30623AB54FE98FA6E8591" author="Allen JA" box="[1280,1418,379,401]" pageId="2" pageNumber="423" pagination="421 - 484" refId="ref7956" refString="Allen JA. 1958. On the basic form and adaptations to habitat in the Lucinacea (Eulamellibranchia). Philosophical Transactions of the Royal Society of London B 241: 421 - 484." type="journal article" year="1958">Allen, 1958</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AD72FE79FC0285B0" author="McAlester AL" box="[806,998,410,432]" pageId="2" pageNumber="423" pagination="433 - 439" refId="ref9804" refString="McAlester AL. 1966. Evolutionary and systematic implications of a transitional Ordovician lucinoid bivalve. Malacologia 3: 433 - 439." type="journal article" year="1966">McAlester, 1966</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623ADADFE79FB9F85AF" author="Boss KJ" box="[1017,1147,410,431]" pageId="2" pageNumber="423" pagination="1 - 1" refId="ref8236" refString="Boss KJ. 1970. Fimbria and its lucinoid affinities (Mollusca, Bivalvia). Breviora 350: 1 - 1 - 16." type="journal article" year="1970">Boss, 1970</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AADAFE79FA6E85B0" author="Reid RGB &amp; Brand DG" box="[1166,1418,410,432]" pageId="2" pageNumber="423" pagination="3 - 24" refId="ref10117" refString="Reid RGB, Brand DG. 1986. Sulfide-oxidising symbiosis in lucinaceans: implications for bivalve evolution. Veliger 29: 3 - 24." type="journal article" year="1986">Reid &amp; Brand, 1986</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE30623AD72FE5AFC3C85CF" author="Hickman CS" box="[806,984,441,463]" pageId="2" pageNumber="423" pagination="43 - 61" refId="ref9517" refString="Hickman CS. 1994. The genus Parvilucina in the Eastern Pacific: making evolutionary sense of a chemosymbiotic species complex. Veliger 37: 43 - 61." type="journal article" year="1994">Hickman, 1994</bibRefCitation>
). A particular problem has concerned the position of the 
<taxonomicName id="4C724D6BFFE30623AA56FE34FB7685ED" box="[1026,1170,471,493]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
, a family with apparently underived anatomical features, but with a relatively late appearance (Cretaceous) in the fossil record. 
<bibRefCitation id="EFE34B19FFE30623ADD0FDD0FBFD8649" author="Allen JA" box="[900,1049,563,585]" pageId="2" pageNumber="423" pagination="421 - 484" refId="ref7956" refString="Allen JA. 1958. On the basic form and adaptations to habitat in the Lucinacea (Eulamellibranchia). Philosophical Transactions of the Royal Society of London B 241: 421 - 484." type="journal article" year="1958">Allen (1958)</bibRefCitation>
regarded the 
<taxonomicName id="4C724D6BFFE30623AA81FDD0FA878649" box="[1237,1379,563,585]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
as basal in his phylogenetic scenario, but 
<bibRefCitation id="EFE34B19FFE30623AB4DFDB1FC8A8687" author="McAlester AL" pageId="2" pageNumber="423" pagination="433 - 439" refId="ref9804" refString="McAlester AL. 1966. Evolutionary and systematic implications of a transitional Ordovician lucinoid bivalve. Malacologia 3: 433 - 439." type="journal article" year="1966">McAlester (1966)</bibRefCitation>
and 
<bibRefCitation id="EFE34B19FFE30623ADFAFD92FBD18687" author="Boss KJ" box="[942,1077,625,647]" pageId="2" pageNumber="423" pagination="1 - 1" refId="ref8236" refString="Boss KJ. 1970. Fimbria and its lucinoid affinities (Mollusca, Bivalvia). Breviora 350: 1 - 1 - 16." type="journal article" year="1970">Boss (1970)</bibRefCitation>
thought it the most derived, the latter suggesting that the outer ctenidial demibranchs, absent in 
<taxonomicName id="4C724D6BFFE30623AA56FD4DFB9186C4" box="[1026,1141,686,708]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
, had been reacquired in 
<taxonomicName id="4C724D6BFFE30623AD72FD2EFC4B86E3" box="[806,943,717,739]" class="Bivalvia" family="Thyasiridae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Thyasiridae</taxonomicName>
&amp; 
<taxonomicName id="4C724D6BFFE30623AD88FD2EFB8986E3" box="[988,1133,717,739]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
. 
<bibRefCitation id="EFE34B19FFE30623AA2AFD2EFAE386E3" author="Boss KJ" box="[1150,1287,717,739]" pageId="2" pageNumber="423" pagination="1 - 1" refId="ref8236" refString="Boss KJ. 1970. Fimbria and its lucinoid affinities (Mollusca, Bivalvia). Breviora 350: 1 - 1 - 16." type="journal article" year="1970">Boss (1970)</bibRefCitation>
considered the 
<taxonomicName id="4C724D6BFFE30623AD00FD08FC378701" box="[852,979,747,769]" class="Bivalvia" family="Fimbriidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Fimbriidae</taxonomicName>
more closely related to the 
<taxonomicName id="4C724D6BFFE30623AB48FD08FA698701" box="[1308,1421,747,769]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
than to 
<taxonomicName id="4C724D6BFFE30623AD29FCE9FBEF8720" box="[893,1035,778,800]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
or 
<taxonomicName id="4C724D6BFFE30623AA79FCE9FB5C8720" box="[1069,1208,778,800]" class="Bivalvia" family="Thyasiridae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Thyasiridae</taxonomicName>
. Subsequent to the discovery of chemosymbiosis in lucinoids, 
<bibRefCitation id="EFE34B19FFE30623AB61FCCAFC25875D" author="Reid RGB &amp; Brand DG" pageId="2" pageNumber="423" pagination="3 - 24" refId="ref10117" refString="Reid RGB, Brand DG. 1986. Sulfide-oxidising symbiosis in lucinaceans: implications for bivalve evolution. Veliger 29: 3 - 24." type="journal article" year="1986">Reid &amp; Brand (1986)</bibRefCitation>
, 
<bibRefCitation id="EFE34B19FFE30623AD84FCA4FBB3875E" author="Reid RGB" box="[976,1111,839,862]" pageId="2" pageNumber="423" pagination="127 - 140" refId="ref10067" refString="Reid RGB. 1990. Evolutionary implications of sulphideoxidising symbioses in bivalves. In: Morton B, ed. The Bivalvia-Proceedings of a Memorial Symposium in Honour of Sir Charles Maurice Yonge, Edinburgh, 1986. Hong Kong: Hong Kong University Press, 127 - 140." type="book chapter" year="1990">Reid (1990)</bibRefCitation>
, and 
<bibRefCitation id="EFE34B19FFE30623AACFFCA4FAB1875E" author="Hickman CS" box="[1179,1365,839,862]" pageId="2" pageNumber="423" pagination="43 - 61" refId="ref9517" refString="Hickman CS. 1994. The genus Parvilucina in the Eastern Pacific: making evolutionary sense of a chemosymbiotic species complex. Veliger 37: 43 - 61." type="journal article" year="1994">Hickman (1994)</bibRefCitation>
considered that the trait was probably plesiomorphic for the superfamily, but partially lost in the 
<taxonomicName id="4C724D6BFFE30623AB51FC66FA6A879B" box="[1285,1422,901,923]" class="Bivalvia" family="Thyasiridae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Thyasiridae</taxonomicName>
and totally lost in the 
<taxonomicName id="4C724D6BFFE30623AA7DFC40FB5F87B9" box="[1065,1211,931,953]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
.
</paragraph>
</subSubSection>
<subSection id="E2FD2F03FFE30623ADFFFC1AFA6E821F" pageId="2" pageNumber="423" type="multiple">
<subSubSection id="C3686563FFE30623ADFFFC1AFAED800C" box="[939,1289,1013,1037]" pageId="2" pageNumber="423" type="multiple">
<paragraph id="8BCD36E8FFE30623ADFFFC1AFAED800C" blockId="2.[939,1289,1013,1037]" box="[939,1289,1013,1037]" pageId="2" pageNumber="423">
<heading id="D0858184FFE30623ADFFFC1AFAED800C" box="[939,1289,1013,1037]" centered="true" fontSize="9" level="2" pageId="2" pageNumber="423" reason="7">
NEW CONCEPT OF 
<taxonomicName id="4C724D6BFFE30623AA2FFC16FAED800C" authorityName="J.Fleming" authorityYear="1828" box="[1147,1289,1013,1037]" class="Bivalvia" family="Lucinoidea" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="435" phylum="Mollusca" rank="family">LUCINOIDEA</taxonomicName>
</heading>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE30623AD72FBFDFA6E821F" pageId="2" pageNumber="423" type="discussion">
<paragraph id="8BCD36E8FFE30623AD72FBFDFA6E821F" blockId="2.[806,1423,1054,1567]" pageId="2" pageNumber="423">
Following the results from the molecular analysis (
<figureCitation id="13492A6DFFE30623AD7AFBDEFC8B8053" box="[814,879,1085,1107]" captionStart="Figure 2" captionStartId="3.[162,240,1657,1676]" captionTargetBox="[162,1442,195,1624]" captionTargetId="figure-157@3.[162,1442,194,1624]" captionTargetPageId="3" captionText="Figure 2. Molecular phylogeny of heterodont and palaeoheterodont bivalves produced by Bayesian analysis of partial sequences from the 18SrRNA gene. Branches with posterior probabilities &lt;85% have been collapsed. Nodal support is posterior probability/bootstrap (Neighbour-joining using Maximum Likelihood distance, 10 000 reps). Details of taxa and methods in Taylor et al., 2005." figureDoi="http://doi.org/10.5281/zenodo.4687489" httpUri="https://zenodo.org/record/4687489/files/figure.png" pageId="2" pageNumber="423">Fig. 2</figureCitation>
), we now restrict the 
<taxonomicName id="4C724D6BFFE30623AA30FBDEFB068053" authorityName="J.Fleming" authorityYear="1828" box="[1124,1250,1085,1107]" class="Bivalvia" family="Lucinoidea" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="435" phylum="Mollusca" rank="family">Lucinoidea</taxonomicName>
to the families 
<taxonomicName id="4C724D6BFFE30623AD72FBB8FC738071" box="[806,919,1115,1137]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE30623AD9BFBB8FBB48071" box="[975,1104,1115,1137]" class="Bivalvia" family="Fimbriidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Fimbriidae</taxonomicName>
, although molecular results (
<figureCitation id="13492A6DFFE30623AD7AFB99FC898090" box="[814,877,1146,1168]" captionStart="Figure 3" captionStartId="4.[142,220,939,958]" captionTargetBox="[142,1422,195,907]" captionTargetId="figure-297@4.[142,1422,194,907]" captionTargetPageId="4" captionText="Figure 3. Molecular phylogeny of Lucinidae (from Williams et al., 2004) based on concatenated gene sequence data from 18S rRNA and 28S rRNA genes. Branches collapsed with posterior probabilities of&gt; 90%. Nodal support is posterior probability/bootstrap (NJ using ML distance, 10 000 reps). *Bootstrap support is 96% for lucinid clade B excluding Phacoides pectinatus." figureDoi="http://doi.org/10.5281/zenodo.4687491" httpUri="https://zenodo.org/record/4687491/files/figure.png" pageId="2" pageNumber="423">Fig. 3</figureCitation>
) indicate the latter nests within the lucinids. Although at the present day there are only two living species, 
<taxonomicName id="4C724D6BFFE30623ADC6FB54FC0B80CC" box="[914,1007,1207,1228]" class="Bivalvia" family="Lucinidae" genus="Fimbria" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE30623ADC6FB54FC0B80CC" box="[914,1007,1207,1228]" italics="true" pageId="2" pageNumber="423">Fimbria</emphasis>
</taxonomicName>
-like bivalves were diverse and abundant during the Mesozoic (
<bibRefCitation id="EFE34B19FFE30623AAC0FB35FAD680EC" author="Monari S" box="[1172,1330,1238,1260]" pageId="2" pageNumber="423" pagination="857 - 884" refId="ref9827" refString="Monari S. 2003. A new genus and species of fimbriid bivalve from the Kimmeridgian of the western Pontides, Turkey, and the phylogeny of the Jurassic Fimbriidae. Palaeontology 46: 857 - 884." type="journal article" year="2003">Monari, 2003</bibRefCitation>
). Of the other families traditionally included within the 
<taxonomicName id="4C724D6BFFE30623AB07FB16FC978129" authorityName="J.Fleming" authorityYear="1828" class="Bivalvia" family="Lucinoidea" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="435" phylum="Mollusca" rank="family">Lucinoidea</taxonomicName>
, the 
<taxonomicName id="4C724D6BFFE30623ADE1FAF0FBDA8129" box="[949,1086,1299,1321]" class="Bivalvia" family="Thyasiridae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Thyasiridae</taxonomicName>
form a monophyletic group (
<figureCitation id="13492A6DFFE30623AD7AFAD1FC8A8148" box="[814,878,1330,1352]" captionStart="Figure 2" captionStartId="3.[162,240,1657,1676]" captionTargetBox="[162,1442,195,1624]" captionTargetId="figure-157@3.[162,1442,194,1624]" captionTargetPageId="3" captionText="Figure 2. Molecular phylogeny of heterodont and palaeoheterodont bivalves produced by Bayesian analysis of partial sequences from the 18SrRNA gene. Branches with posterior probabilities &lt;85% have been collapsed. Nodal support is posterior probability/bootstrap (Neighbour-joining using Maximum Likelihood distance, 10 000 reps). Details of taxa and methods in Taylor et al., 2005." figureDoi="http://doi.org/10.5281/zenodo.4687489" httpUri="https://zenodo.org/record/4687489/files/figure.png" pageId="2" pageNumber="423">Fig. 2</figureCitation>
) basal within the Heterodonta excepting the 
<taxonomicName id="4C724D6BFFE30623AD72FAB2FC448167" box="[806,928,1361,1383]" class="Bivalvia" family="Carditidae" kingdom="Animalia" order="Carditoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Carditidae</taxonomicName>
/ 
<taxonomicName id="4C724D6BFFE30623ADFDFAB2FBAF8167" authorityName="Ferussac" authorityYear="1822" box="[937,1099,1361,1383]" class="Bivalvia" family="Crassatellidae" kingdom="Animalia" order="Carditoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Crassatellidae</taxonomicName>
clade. The 
<taxonomicName id="4C724D6BFFE30623AAABFAB2FA698167" box="[1279,1421,1361,1383]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
form a monophyletic group allied to the 
<taxonomicName id="4C724D6BFFE30623AB47FA8CFA628185" authorityName="R.B.Newton" authorityYear="1891" box="[1299,1414,1391,1413]" class="Bivalvia" family="Arcticidae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Arcticidae</taxonomicName>
/ 
<taxonomicName id="4C724D6BFFE30623AD72FA6DFC7D81A4" authorityName="Rafinesque" authorityYear="1815" box="[806,921,1422,1444]" class="Bivalvia" family="Veneridae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Veneridae</taxonomicName>
/ 
<taxonomicName id="4C724D6BFFE30623ADF6FA6DFBF081A4" authorityName="Lamarck" authorityYear="1809" box="[930,1044,1422,1444]" class="Bivalvia" family="Mactridae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Mactridae</taxonomicName>
clades. No species of 
<taxonomicName id="4C724D6BFFE30623AB49FA6DFCB281C3" authorityName="H.Adams &amp; A.Adams" authorityYear="1857" class="Bivalvia" family="Cyrenoididae" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Cyrenoididae</taxonomicName>
has yet been analysed, but from anatomical characters a relationship with 
<taxonomicName id="4C724D6BFFE30623AA0AFA28FB2B81E1" box="[1118,1231,1483,1505]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
is unlikely. The status of the fossil taxa 
<taxonomicName id="4C724D6BFFE30623AA1CFA09FB0B8200" authorityName="Cox" authorityYear="1929" box="[1096,1263,1514,1536]" class="Bivalvia" family="Mactromyidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Mactromyidae</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE30623AAA9FA09FA6A8200" authorityName="P.A.Johnston" authorityYear="1993" box="[1277,1422,1514,1536]" class="Bivalvia" family="Paracyclidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Paracyclidae</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE30623AD0DF9EAFC38821F" authorityName="Horny" authorityYear="1960" box="[857,988,1545,1567]" class="Bivalvia" family="Babinkidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Babinkidae</taxonomicName>
within the 
<taxonomicName id="4C724D6BFFE30623AA30F9EAFB06821F" authorityName="J.Fleming" authorityYear="1828" box="[1124,1250,1545,1567]" class="Bivalvia" family="Lucinoidea" kingdom="Animalia" order="Veneroida" pageId="2" pageNumber="435" phylum="Mollusca" rank="family">Lucinoidea</taxonomicName>
is unresolved.
</paragraph>
</subSubSection>
</subSection>
<subSubSection id="C3686563FFE30623ADB3F9B7FB28826C" box="[999,1228,1620,1644]" pageId="2" pageNumber="423" type="multiple">
<paragraph id="8BCD36E8FFE30623ADB3F9B7FB28826C" blockId="2.[999,1228,1620,1644]" box="[999,1228,1620,1644]" pageId="2" pageNumber="423">
<heading id="D0858184FFE30623ADB3F9B7FB28826C" allCaps="true" box="[999,1228,1620,1644]" centered="true" fontSize="10" level="1" pageId="2" pageNumber="423" reason="1">
THE 
<taxonomicName id="4C724D6BFFE30623AA7FF9B7FB28826C" box="[1067,1228,1620,1644]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">LUCINIDAE</taxonomicName>
</heading>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE30625AD72F960FE078370" lastPageId="4" lastPageNumber="425" pageId="2" pageNumber="423" type="description">
<paragraph id="8BCD36E8FFE30625AD72F960FD718129" blockId="2.[806,1422,1667,1904]" lastBlockId="4.[142,758,1115,1904]" lastPageId="4" lastPageNumber="425" pageId="2" pageNumber="423">
Shells of 
<taxonomicName id="4C724D6BFFE30623ADC0F960FBE18299" box="[916,1029,1667,1689]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="2" pageNumber="423" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
are usually white, subcircular in outline and range from discoidal to subspherical in profile. Living species range in height from around 3.0 − 
<quantity id="4C8A9B0DFFE30623AD30F93CFC2782F5" box="[868,963,1759,1781]" metricMagnitude="-1" metricUnit="m" metricValue="1.4" pageId="2" pageNumber="423" unit="mm" value="140.0">140 mm</quantity>
. External sculpture mainly comprises variations of commarginal lamellae and radial ribbing is usually absent or subordinate. Posterior sulci are often present. However, many lucinids have smooth, unornamented shells. Ligaments range from long external to short internal. There are usually two or less cardinal teeth in each valve, with lateral teeth present in some taxa. In many lucinids hinge teeth are highly reduced or completely absent. One of the most distinctive features of lucinids is the anterior adductor muscle scar. The adductor muscles are usually unequal in size, and most (but not all) lucinids possess a distinctive elongate, anterior adductor muscle scar that diverges inwards from the pallial line. There is no posterior pallial sinus. Shell microstructure usually consists of three layers, an outer spherulitic prismatic layer, a middle layer of crossed-lamellar structure and within the pallial myostracum, an inner complex crossed lamellar layer often with intercalated prismatic sheets (
<bibRefCitation id="EFE34B19FFE50625AF7AFAF0FD6D8129" author="Taylor JD &amp; Kennedy WJ &amp; Hall A" box="[302,649,1299,1321]" pageId="4" pageNumber="425" pagination="253 - 294" refId="ref10581" refString="Taylor JD, Kennedy WJ, Hall A. 1973. The shell structure and mineralogy of the Bivalvia. II. Lucinacea-Clavagellacea. Conclusions. Bulletin of the British Museum (Natural History), Zoology 22: 253 - 294." type="journal article" year="1973">Taylor, Kennedy &amp; Hall, 1973</bibRefCitation>
).
</paragraph>
<caption id="DF0D6660FFE20622AEF6F99AFE0082E4" ID-DOI="http://doi.org/10.5281/zenodo.4687489" ID-Zenodo-Dep="4687489" httpUri="https://zenodo.org/record/4687489/files/figure.png" pageId="3" pageNumber="424" startId="3.[162,240,1657,1676]" targetBox="[162,1442,195,1624]" targetPageId="3">
<paragraph id="8BCD36E8FFE20622AEF6F99AFE0082E4" blockId="3.[162,1441,1657,1764]" pageId="3" pageNumber="424">
<emphasis id="B906EAFAFFE20622AEF6F99AFEEE828C" bold="true" box="[162,266,1657,1676]" pageId="3" pageNumber="424">Figure 2.</emphasis>
Molecular phylogeny of heterodont and palaeoheterodont bivalves produced by Bayesian analysis of partial sequences from the 18SrRNA gene. Branches with posterior probabilities &lt;85% have been collapsed. Nodal support is posterior probability/bootstrap (Neighbour-joining using Maximum Likelihood distance, 10 000 reps). Details of taxa and methods in Taylor 
<emphasis id="B906EAFAFFE20622AF3EF932FE7382E4" box="[362,407,1745,1764]" italics="true" pageId="3" pageNumber="424">et al</emphasis>
., 2005.
</paragraph>
</caption>
<caption id="DF0D6660FFE50625AEDAFC48FEE48017" ID-DOI="http://doi.org/10.5281/zenodo.4687491" ID-Zenodo-Dep="4687491" httpUri="https://zenodo.org/record/4687491/files/figure.png" pageId="4" pageNumber="425" startId="4.[142,220,939,958]" targetBox="[142,1422,195,907]" targetPageId="4">
<paragraph id="8BCD36E8FFE50625AEDAFC48FEE48017" blockId="4.[142,1422,939,1047]" pageId="4" pageNumber="425">
<emphasis id="B906EAFAFFE50625AEDAFC48FF1287BE" bold="true" box="[142,246,939,958]" pageId="4" pageNumber="425">Figure 3.</emphasis>
Molecular phylogeny of 
<taxonomicName id="4C724D6BFFE50625AFAAFC48FD8287BE" box="[510,614,939,958]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="4" pageNumber="425" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
(from 
<bibRefCitation id="EFE34B19FFE50625ACFAFC48FC6187BF" author="Williams ST &amp; Taylor JD &amp; Glover EA" box="[686,901,939,959]" pageId="4" pageNumber="425" pagination="187 - 202" refId="ref10661" refString="Williams ST, Taylor JD, Glover EA. 2004. Molecular phylogeny of the Lucinoidea (Bivalvia): non-monophyly and separate acquisition of bacterial chemosymbiosis. Journal of Molluscan Studies 70: 187 - 202." type="journal article" year="2004">
Williams 
<emphasis id="B906EAFAFFE50625AD47FC4FFCA487BE" box="[787,832,939,958]" italics="true" pageId="4" pageNumber="425">et al</emphasis>
., 2004
</bibRefCitation>
) based on concatenated gene sequence data from 18S rRNA and 28S rRNA genes. Branches collapsed with posterior probabilities of&gt; 90%. Nodal support is posterior probability/bootstrap (NJ using ML distance, 10 000 reps). *Bootstrap support is 96% for lucinid clade B excluding 
<taxonomicName id="4C724D6BFFE50625AB71FC05FF1D8016" baseAuthorityName="Gmelin" baseAuthorityYear="1792" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="4" pageNumber="425" phylum="Mollusca" rank="species" species="pectinatus">
<emphasis id="B906EAFAFFE50625AB71FC05FF1D8016" italics="true" pageId="4" pageNumber="425">Phacoides pectinatus</emphasis>
</taxonomicName>
.
</paragraph>
</caption>
<paragraph id="8BCD36E8FFE50625AEF3FAD1FE078370" blockId="4.[142,758,1115,1904]" pageId="4" pageNumber="425">
Anatomically, lucinids have a number of distinctive features (
<figureCitation id="13492A6DFFE50625AEA9FAB2FEDB8167" box="[253,319,1361,1383]" captionStart="Figure 4" captionStartId="4.[806,884,1602,1621]" captionTargetBox="[810,1419,1114,1570]" captionTargetId="figure-355@4.[810,1419,1114,1570]" captionTargetPageId="4" captionText="Figure 4. General anatomy of Anodontia philippiana, Dampier, Western Australia, with left valve and mantle removed. Abbreviations: aa, anterior adductor muscle; exa, exhalant aperture; f, foot; fm, fused mantle; ld, left demibranch of ctenidia; me, mantle edge; mg, mantle gills on septum; p, periostracum; pa, posterior adductor muscle. Shell length = 40 mm" figureDoi="http://doi.org/10.5281/zenodo.4687493" httpUri="https://zenodo.org/record/4687493/files/figure.png" pageId="4" pageNumber="425">Fig. 4</figureCitation>
). Ctenidia are usually large, comprising inner demibranchs only; the filaments are thick with a narrow, outer ciliated zone and an extended abfrontal zone comprising bacteriocytes, intercalary cells and mucocytes. Distal portions of gill filaments are often fused into cylindrical channels (
<bibRefCitation id="EFE34B19FFE50625AC30FA09FEEE821F" author="Distel DL &amp; Felbeck H" pageId="4" pageNumber="425" pagination="79 - 86" refId="ref8879" refString="Distel DL, Felbeck H. 1987. Endosymbiosis in the lucinid clams Lucinoma aequizonata, Lucinoma annulata and Lucina floridana: a rexamination of the functional morphology of the gills as bacteria-bearing organs. Marine Biology 96: 79 - 86." type="journal article" year="1987">Distel &amp; Felbeck, 1987</bibRefCitation>
). Labial palps are highly reduced, consisting of small folds at the edge of the lips. Posterior inhalant and exhalant apertures are present, the latter with an eversible tube. The foot is elongate, usually cylindrical and highly extensible with a differentiated, ciliated and glandular tip. A large pallial blood vessel runs diagonally from the auricle to near the ventral tip of the anterior adductor muscle, often leaving a deep impression in the shell interior. The inner mantle around the anterior adductor muscle is often thickened by blood space or in some species thrown into complex folds as mantle gills.
</paragraph>
</subSubSection>
<caption id="DF0D6660FFE50625AD72F9A1FBE38306" ID-DOI="http://doi.org/10.5281/zenodo.4687493" ID-Zenodo-Dep="4687493" httpUri="https://zenodo.org/record/4687493/files/figure.png" pageId="4" pageNumber="425" startId="4.[806,884,1602,1621]" targetBox="[810,1419,1114,1570]" targetPageId="4">
<paragraph id="8BCD36E8FFE50625AD72F9A1FBE38306" blockId="4.[806,1423,1602,1798]" pageId="4" pageNumber="425">
<emphasis id="B906EAFAFFE50625AD72F9A1FC6A8255" bold="true" box="[806,910,1602,1621]" pageId="4" pageNumber="425">Figure 4.</emphasis>
General anatomy of 
<taxonomicName id="4C724D6BFFE50625AADBF9A1FC668272" authority=", Dampier" authorityName="Dampier" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="4" pageNumber="425" phylum="Mollusca" rank="species" species="philippiana">
<emphasis id="B906EAFAFFE50625AADBF9A1FA638255" box="[1167,1415,1602,1621]" italics="true" pageId="4" pageNumber="425">Anodontia philippiana</emphasis>
, Dampier
</taxonomicName>
, Western Australia, with left valve and mantle removed. Abbreviations: aa, anterior adductor muscle; exa, exhalant aperture; f, foot; fm, fused mantle; ld, left demibranch of ctenidia; me, mantle edge; mg, mantle gills on septum; p, periostracum; pa, posterior adductor muscle. Shell length = 40 mm
</paragraph>
</caption>
<subSubSection id="C3686563FFE40624AF10FF21FD8C84DA" box="[324,616,194,218]" pageId="5" pageNumber="426" type="multiple">
<paragraph id="8BCD36E8FFE40624AF10FF21FD8C84DA" blockId="5.[324,616,194,218]" box="[324,616,194,218]" pageId="5" pageNumber="426">
DIVERSITY OF 
<taxonomicName id="4C724D6BFFE40624AFBEFF21FD8C84DA" box="[490,616,194,218]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">LUCINIDAE</taxonomicName>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE40624AEF6FF08FD26807A" pageId="5" pageNumber="426" type="discussion">
<paragraph id="8BCD36E8FFE40624AEF6FF08FD26807A" blockId="5.[162,779,235,1146]" pageId="5" pageNumber="426">
It is increasingly recognized that the family 
<taxonomicName id="4C724D6BFFE40624ACC3FF08FCEC8501" box="[663,776,235,257]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
is much more diverse than previous assessments. Using genera as a proxy for morphological disparity and the revision in the ‘Bivalve Treatise’ (
<bibRefCitation id="EFE34B19FFE40624ACFEFEA4FF3E857B" author="Chavan A" pageId="5" pageNumber="426" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan, 1969</bibRefCitation>
) as a starting point, 44 valid genera containing Recent species were recognized. By 2005 this had increased to 58 published genera, and another 15 new genera are in press or preparation (E. A. Glover &amp; J. D. Taylor, unpubl. data; Cosel &amp; Bouchet, in press) = 73; while we are aware of perhaps another 15 distinct but as yet unworked taxa = 88. This represents a doubling of the known genera since 1969. From our experience, we anticipate that there are many more undescribed taxa from mid- and deep-water environments, especially species &lt;
<quantity id="4C8A9B0DFFE40624AF0AFD7BFE4986AD" box="[350,429,664,685]" metricMagnitude="-2" metricUnit="m" metricValue="1.0" pageId="5" pageNumber="426" unit="mm" value="10.0">10 mm</quantity>
in size. At the specific level there is a similar unrecognized diversity. For example, amongst the larger taxa, many new species of 
<taxonomicName id="4C724D6BFFE40624AC9BFD35FF06870A" authorityName="Dall" authorityYear="1901" class="Bivalvia" family="Lucinidae" genus="Lucinoma" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE40624AC9BFD35FF06870A" italics="true" pageId="5" pageNumber="426">Lucinoma</emphasis>
</taxonomicName>
are being discovered from cold seeps and oxygen minimum zones (von Cosel, in press; 
<bibRefCitation id="EFE34B19FFE40624AC11FCF0FF388747" author="Oliver PG &amp; Holmes AM" pageId="5" pageNumber="426" pagination="63 - 77" refId="ref9969" refString="Oliver PG, Holmes AM. 2006. A new species of Lucinoma (Bivalvia: Lucinoidea) from the oxygen minimum zone of the Oman margin, Arabian Sea. Journal of Conchology 39: 63 - 77." type="journal article" year="2006">Oliver &amp; Holmes, 2006</bibRefCitation>
). Amongst the 
<taxonomicName id="4C724D6BFFE40624AFCFFCD2FDF58746" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[411,529,817,838]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE40624AFCFFCD2FDF58746" box="[411,529,817,838]" italics="true" pageId="5" pageNumber="426">Anodontia</emphasis>
</taxonomicName>
group from shallow water tropical habitats, we now identify 25 species compared to the possible eight we thought existed only three years ago (Taylor &amp; Glover, 2005). Furthermore, Cosel &amp; Bouchet (in press) are describing many new species from deeper water across the Indo-West Pacific. Additionally, upon closer study, a number of apparently well-known tropical species turn out to be complexes of similar species (
<bibRefCitation id="EFE34B19FFE40624AFAAFBC4FCE1803C" author="Taylor JD &amp; Glover EA" box="[510,773,1063,1085]" pageId="5" pageNumber="426" pagination="93 - 122" refId="ref10349" refString="Taylor JD, Glover EA. 1997. The lucinid bivalve genus Cardiolucina (Mollusca, Bivalvia, Lucinidae): systematics, anatomy and relationships. Bulletin of the Natural History Museum, London (Zoology) 63: 93 - 122." type="journal article" year="1997">Taylor &amp; Glover, 1997</bibRefCitation>
, 
<bibRefCitation id="EFE34B19FFE40624AEF6FBA6FF38805B" author="Taylor JD &amp; Glover EA" box="[162,220,1093,1115]" pageId="5" pageNumber="426" pagination="317 - 336" refId="ref10443" refString="Taylor JD, Glover EA. 2002. Lamellolucina: a new genus of lucinid bivalve with four new species from the Indo-West Pacific. Journal of Conchology 37: 317 - 336." type="journal article" year="2002">2002</bibRefCitation>
). Our current estimates suggest that there may be as many as 500 extant species of 
<taxonomicName id="4C724D6BFFE40624AC1CFB87FD5A807A" box="[584,702,1124,1146]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
.
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE40624AEE9FB4CFDE780E5" pageId="5" pageNumber="426" type="multiple">
<paragraph id="8BCD36E8FFE40624AEE9FB4CFDE780E5" blockId="5.[189,752,1199,1253]" pageId="5" pageNumber="426">
RELATIONSHIP OF 
<taxonomicName id="4C724D6BFFE40624AFC5FB4CFDEB80C5" authority="TO OTHER BIVALVE GROUPS" box="[401,527,1199,1223]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">LUCINIDAE</taxonomicName>
TO OTHER BIVALVE GROUPS
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE40624AEF6FB14FB7C8072" pageId="5" pageNumber="426" type="discussion">
<paragraph id="8BCD36E8FFE40624AEF6FB14FDC5827D" blockId="5.[162,779,1271,1907]" pageId="5" pageNumber="426">
<bibRefCitation id="EFE34B19FFE40624AEF6FB14FE80810D" author="McAlester AL" box="[162,356,1271,1293]" pageId="5" pageNumber="426" pagination="433 - 439" refId="ref9804" refString="McAlester AL. 1966. Evolutionary and systematic implications of a transitional Ordovician lucinoid bivalve. Malacologia 3: 433 - 439." type="journal article" year="1966">McAlester (1966)</bibRefCitation>
suggested that 
<taxonomicName id="4C724D6BFFE40624AC42FB14FD93810C" box="[534,631,1271,1292]" class="Bivalvia" family="Babinkidae" genus="Babinka" higherTaxonomySource="GBIF" kingdom="Animalia" order="Venerida" pageId="5" pageNumber="426" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE40624AC42FB14FD93810C" box="[534,631,1271,1292]" italics="true" pageId="5" pageNumber="426">Babinka</emphasis>
</taxonomicName>
and the lucinoids were derived from monoplacophorans independently from the rest of the bivalves and 
<bibRefCitation id="EFE34B19FFE40624AC20FAD6FCEE814B" author="Pojeta J" box="[628,778,1333,1355]" pageId="5" pageNumber="426" pagination="225 - 246" refId="ref10035" refString="Pojeta J. 1978. The origin and early taxonomic diversification of. Pelecypods. Philosophical Transactions of the Royal Society of London Series B. 284: 225 - 246." type="journal article" year="1978">Pojeta (1978)</bibRefCitation>
considered them a sufficiently distinct group to warrant separation at subclass level (Lucinata). However, these concepts were countered by 
<bibRefCitation id="EFE34B19FFE40624AC6EFA72FD5F81A7" author="Boss KJ" box="[570,699,1425,1447]" pageId="5" pageNumber="426" pagination="128 - 131" refId="ref8218" refString="Boss KJ. 1969. Lucinacea and their heterodont affinities. Nautilus 82: 128 - 131." type="journal article" year="1969">Boss (1969</bibRefCitation>
, 
<bibRefCitation id="EFE34B19FFE40624AC9FFA72FCE781A7" author="Boss KJ" box="[715,771,1425,1447]" pageId="5" pageNumber="426" pagination="1 - 1" refId="ref8236" refString="Boss KJ. 1970. Fimbria and its lucinoid affinities (Mollusca, Bivalvia). Breviora 350: 1 - 1 - 16." type="journal article" year="1970">1970</bibRefCitation>
) who pointed out the many morphological characters of lucinids that are shared with heterodont bivalves. Subsequent morphological and molecular analyses have confirmed the position of the 
<taxonomicName id="4C724D6BFFE40624AC7BF9E8FD448221" box="[559,672,1547,1569]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
amongst the Heterodonta (
<bibRefCitation id="EFE34B19FFE40624AF2EF9C9FDED8240" author="Healy JM" box="[378,521,1578,1600]" pageId="5" pageNumber="426" pagination="155 - 166" refId="ref9446" refString="Healy JM. 1995. Comparative spermatozoal ultrastructure and its taxonomic and phylogenetic significance in the bivalve order Veneroidea. Memoires Museum National d'Histoire Naturelle, Paris 166: 155 - 166." type="journal article" year="1995">Healy, 1995</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AC4FF9C9FF3F825E" author="Steiner G &amp; Hammer S" pageId="5" pageNumber="426" pagination="11 - 29" refId="ref10291" refString="Steiner G, Hammer S. 2000. Molecular phylogeny of the Bivalvia inferred from 18 S rDNA sequences with particular reference to the Pteriomorphia. In: Harper EM, Taylor JD, Crame JA, eds. The Evolutionary Biology of the Bivalvia. Geological Society of London Special Publication 177: 11 - 29." type="journal article" year="2000">Steiner &amp; Hammer, 2000</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AEB2F9AAFE18825E" author="Giribet G &amp; Wheeler W" box="[230,508,1609,1631]" pageId="5" pageNumber="426" pagination="271 - 324" refId="ref9138" refString="Giribet G, Wheeler W. 2002. On bivalve phylogeny: a highlevel analysis of the Bivalvia (Mollusca) based on combined morphology and DNA sequence data. Invertebrate Biology 121: 271 - 324." type="journal article" year="2002">Giribet &amp; Wheeler, 2002</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AC53F9AAFCE2825E" author="Giribet G &amp; Distel DL" box="[519,774,1609,1631]" pageId="5" pageNumber="426" pagination="45 - 90" refId="ref9097" refString="Giribet G, Distel DL. 2004. Bivalve phylogeny and molecular data. In: Lydeard C, Lindberg D, eds. Molecular Systematics and PhyloGeographyraphy of Mollusks. Washington: Smithsonian Institution Press, 45 - 90." type="book chapter" year="2004">Giribet &amp; Distel, 2004</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AEF6F984FDF2827D" author="Williams ST &amp; Taylor JD &amp; Glover EA" box="[162,534,1639,1661]" pageId="5" pageNumber="426" pagination="187 - 202" refId="ref10661" refString="Williams ST, Taylor JD, Glover EA. 2004. Molecular phylogeny of the Lucinoidea (Bivalvia): non-monophyly and separate acquisition of bacterial chemosymbiosis. Journal of Molluscan Studies 70: 187 - 202." type="journal article" year="2004">Williams, Taylor &amp; Glover, 2004</bibRefCitation>
).
</paragraph>
<paragraph id="8BCD36E8FFE40624AEEFF965FC058720" blockId="5.[162,779,1271,1907]" lastBlockId="5.[826,1442,195,1138]" pageId="5" pageNumber="426">
Some workers have proposed, on the basis of morphology, a phylogenetic relationship between the Crassatelloidea and 
<taxonomicName id="4C724D6BFFE40624AFDDF920FDE382D9" authorityName="J.Fleming" authorityYear="1828" box="[393,519,1731,1753]" class="Bivalvia" family="Lucinoidea" kingdom="Animalia" order="Veneroida" pageId="5" pageNumber="435" phylum="Mollusca" rank="family">Lucinoidea</taxonomicName>
(in old concept) (
<bibRefCitation id="EFE34B19FFE40624AC90F920FF3F82F8" author="Allen JA" pageId="5" pageNumber="426" pagination="421 - 484" refId="ref7956" refString="Allen JA. 1958. On the basic form and adaptations to habitat in the Lucinacea (Eulamellibranchia). Philosophical Transactions of the Royal Society of London B 241: 421 - 484." type="journal article" year="1958">Allen, 1958</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AEA5F901FE9282F8" author="Boss KJ" box="[241,374,1762,1784]" pageId="5" pageNumber="426" pagination="128 - 131" refId="ref8218" refString="Boss KJ. 1969. Lucinacea and their heterodont affinities. Nautilus 82: 128 - 131." type="journal article" year="1969">Boss, 1969</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AFDFF901FCE282F7" author="Scarlato OA &amp; Starobogatov YI" box="[395,774,1762,1784]" pageId="5" pageNumber="426" pagination="217 - 224" refId="ref10187" refString="Scarlato OA, Starobogatov YI. 1978. Phylogenetic relations and the early evolution of the class Bivalvia. Philosophical Transactions of the Royal Society of London, Series B 284: 217 - 224." type="journal article" year="1978">Scarlato &amp; Starobogatov, 1978</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AEF6F8E2FEB68316" author="Johnston PA" box="[162,338,1793,1815]" pageId="5" pageNumber="426" pagination="1 - 134" refId="ref9609" refString="Johnston PA. 1993. Lower Devonian Pelecypoda from southeastern Australia. Memoirs of the Association of Australasian Palaeontologists 14: 1 - 134." type="journal article" year="1993">Johnston, 1993</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AF0BF8E2FE1F8317" author="Morton B" box="[351,507,1793,1815]" pageId="5" pageNumber="426" pagination="337 - 359" refId="ref9898" refString="Morton B. 1996. The evolutionary history of the Bivalvia. In: Taylor JD, ed. Origin and Evolutionary Radiation of the Mollusca. Oxford: Oxford University Press, 337 - 359." type="book chapter" year="1996">Morton, 1996</bibRefCitation>
). Molecular analyses of species of 
<taxonomicName id="4C724D6BFFE40624AF7AF8FCFE438335" authorityName="d Orbigny" authorityYear="1844" box="[302,423,1823,1845]" class="Bivalvia" family="Astartidae" kingdom="Animalia" order="Carditoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Astartidae</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE40624AFAEF8FCFD908335" box="[506,628,1823,1845]" class="Bivalvia" family="Carditidae" kingdom="Animalia" order="Carditoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Carditidae</taxonomicName>
(
<bibRefCitation id="EFE34B19FFE40624ACDBF8FCFEA28353" author="Giribet G &amp; Wheeler W" pageId="5" pageNumber="426" pagination="271 - 324" refId="ref9138" refString="Giribet G, Wheeler W. 2002. On bivalve phylogeny: a highlevel analysis of the Bivalvia (Mollusca) based on combined morphology and DNA sequence data. Invertebrate Biology 121: 271 - 324." type="journal article" year="2002">Giribet &amp; Wheeler, 2002</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AF06F8DDFDB18354" author="Giribet G &amp; Distel DL" box="[338,597,1854,1876]" pageId="5" pageNumber="426" pagination="45 - 90" refId="ref9097" refString="Giribet G, Distel DL. 2004. Bivalve phylogeny and molecular data. In: Lydeard C, Lindberg D, eds. Molecular Systematics and PhyloGeographyraphy of Mollusks. Washington: Smithsonian Institution Press, 45 - 90." type="book chapter" year="2004">Giribet &amp; Distel, 2004</bibRefCitation>
), indicated that they group together in a monophyletic clade that forms a sister group to the remaining heterodont bivalves, but with no close relationship to the 
<taxonomicName id="4C724D6BFFE40624AD6EFEE2FC4A8517" box="[826,942,257,279]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
. Inclusion of a crassatellid species, 
<taxonomicName id="4C724D6BFFE40624AB1EFEE2FB2F8535" authority="(Lamarck, 1818)" baseAuthorityName="Lamarck" baseAuthorityYear="1818" class="Bivalvia" family="Crassatellidae" genus="Eucrassatella" kingdom="Animalia" order="Carditoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="species" species="donacina">
<emphasis id="B906EAFAFFE40624AB1EFEE2FC1F8534" italics="true" pageId="5" pageNumber="426">Eucrassatella donacina</emphasis>
(Lamarck, 1818)
</taxonomicName>
, in the molecular analysis (
<bibRefCitation id="EFE34B19FFE40624ADE4FEDDFAA08554" author="Taylor JD &amp; Glover EA &amp; Williams ST" box="[944,1348,318,340]" pageId="5" pageNumber="426" pagination="261 - 288" refId="ref10514" refString="Taylor JD, Glover EA, Williams ST. 2005. Another bloody bivalve: anatomy and relationships of Eucrassatella donacina from south Western Australia (Mollusca: Bivalvia: Crassatellidae). In: Wells FE, Walker DI, Kendrick GA, eds. The Marine Fauna and Flora of Esperance, Western Australia. Perth: Western Australian Museum, 261 - 288." type="book chapter" year="2005">Taylor, Glover &amp; Williams, 2005</bibRefCitation>
) shows (
<figureCitation id="13492A6DFFE40624AD16FEBEFC668573" box="[834,898,349,371]" captionStart="Figure 2" captionStartId="3.[162,240,1657,1676]" captionTargetBox="[162,1442,195,1624]" captionTargetId="figure-157@3.[162,1442,194,1624]" captionTargetPageId="3" captionText="Figure 2. Molecular phylogeny of heterodont and palaeoheterodont bivalves produced by Bayesian analysis of partial sequences from the 18SrRNA gene. Branches with posterior probabilities &lt;85% have been collapsed. Nodal support is posterior probability/bootstrap (Neighbour-joining using Maximum Likelihood distance, 10 000 reps). Details of taxa and methods in Taylor et al., 2005." figureDoi="http://doi.org/10.5281/zenodo.4687489" httpUri="https://zenodo.org/record/4687489/files/figure.png" pageId="5" pageNumber="426">Fig. 2</figureCitation>
) that a combined monophyletic clade of 
<taxonomicName id="4C724D6BFFE40624AD6EFE98FC518591" authorityName="d Orbigny" authorityYear="1844" box="[826,949,379,401]" class="Bivalvia" family="Astartidae" kingdom="Animalia" order="Carditoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Astartidae</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE40624AD9DFE98FB898591" authorityName="Ferussac" authorityYear="1822" box="[969,1133,379,401]" class="Bivalvia" family="Crassatellidae" kingdom="Animalia" order="Carditoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Crassatellidae</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE40624AAECFE98FAD68591" box="[1208,1330,379,401]" class="Bivalvia" family="Carditidae" kingdom="Animalia" order="Carditoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Carditidae</taxonomicName>
forms a basal sister group to all other heterodont bivalves including the Anomalodesmata. The monophyly of this clade is corroborated by morphological characters, including those of sperm (
<bibRefCitation id="EFE34B19FFE40624AA0AFE15FB07860C" author="Healy JM" box="[1118,1251,502,524]" pageId="5" pageNumber="426" pagination="155 - 166" refId="ref9446" refString="Healy JM. 1995. Comparative spermatozoal ultrastructure and its taxonomic and phylogenetic significance in the bivalve order Veneroidea. Memoires Museum National d'Histoire Naturelle, Paris 166: 155 - 166." type="journal article" year="1995">Healy, 1995</bibRefCitation>
) and presence of extracellular haemoglobin of high molecular weight in all three families. This result supports the idea, based on morphological studies, that the Crassatelloidea and Carditoidea are the most primitive of the living heterodont bivalves (
<bibRefCitation id="EFE34B19FFE40624AA52FD6CFB7086A5" author="Yonge CM" box="[1030,1172,655,677]" pageId="5" pageNumber="426" pagination="493 - 527" refId="ref10699" refString="Yonge CM. 1969. Functional morphology and evolution within the Carditacea (Bivalvia). Proceedings of the Malacological Society of London 38: 493 - 527." type="journal article" year="1969">Yonge, 1969</bibRefCitation>
). Suggestions of a relationship between the 
<taxonomicName id="4C724D6BFFE40624AA6AFD4DFB0786C4" authorityName="Ferussac" authorityYear="1822" box="[1086,1251,686,708]" class="Bivalvia" family="Crassatellidae" kingdom="Animalia" order="Carditoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Crassatellidae</taxonomicName>
and any of the families previously included in the 
<taxonomicName id="4C724D6BFFE40624AA84FD2EFAAA86E3" authorityName="J.Fleming" authorityYear="1828" box="[1232,1358,717,739]" class="Bivalvia" family="Lucinoidea" kingdom="Animalia" order="Veneroida" pageId="5" pageNumber="435" phylum="Mollusca" rank="family">Lucinoidea</taxonomicName>
(
<bibRefCitation id="EFE34B19FFE40624AB09FD2EFC978701" author="Allen JA" pageId="5" pageNumber="426" pagination="421 - 484" refId="ref7956" refString="Allen JA. 1958. On the basic form and adaptations to habitat in the Lucinacea (Eulamellibranchia). Philosophical Transactions of the Royal Society of London B 241: 421 - 484." type="journal article" year="1958">Allen, 1958</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624ADD6FD0FFBE48701" author="Boss KJ" box="[898,1024,747,769]" pageId="5" pageNumber="426" pagination="128 - 131" refId="ref8218" refString="Boss KJ. 1969. Lucinacea and their heterodont affinities. Nautilus 82: 128 - 131." type="journal article" year="1969">Boss, 1969</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AA5AFD08FB248700" author="Johnston PA" box="[1038,1216,747,769]" pageId="5" pageNumber="426" pagination="1 - 134" refId="ref9609" refString="Johnston PA. 1993. Lower Devonian Pelecypoda from southeastern Australia. Memoirs of the Association of Australasian Palaeontologists 14: 1 - 134." type="journal article" year="1993">Johnston, 1993</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE40624AA9BFD0FFA8F8701" author="Morton B" box="[1231,1387,747,769]" pageId="5" pageNumber="426" pagination="337 - 359" refId="ref9898" refString="Morton B. 1996. The evolutionary history of the Bivalvia. In: Taylor JD, ed. Origin and Evolutionary Radiation of the Mollusca. Oxford: Oxford University Press, 337 - 359." type="book chapter" year="1996">Morton, 1996</bibRefCitation>
) are not supported.
</paragraph>
<paragraph id="8BCD36E8FFE40624AD07FCCAFB7C8072" blockId="5.[826,1442,195,1138]" pageId="5" pageNumber="426">
A molecular phylogeny of the Anomalodesmata (
<bibRefCitation id="EFE34B19FFE40624AD15FCA4FB52875D" author="Dreyer H &amp; Steiner G &amp; Harper EM" box="[833,1206,839,861]" pageId="5" pageNumber="426" pagination="229 - 246" refId="ref8922" refString="Dreyer H, Steiner G, Harper EM. 2003. Molecular phylogeny of Anomalodesmata (Mollusca: Bivalvia) inferred from 18 S rRNA sequences. Zoological Journal of the Linnean Society 139: 229 - 246." type="journal article" year="2003">Dreyer, Steiner &amp; Harper, 2003</bibRefCitation>
) showed them rooting, in parsimony analysis, as a monophyletic clade amongst basal heterodonts between the Carditoidea/ Crassatelloidea clade and the rest of the heterodonts but in a maximum likelihood analysis they formed a sister group to the 
<taxonomicName id="4C724D6BFFE40624AA41FC02FB6E87F7" box="[1045,1162,993,1015]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
. Nevertheless, we are at present unable to identify a sister group to the 
<taxonomicName id="4C724D6BFFE40624AD6EFBFDFC4F8034" box="[826,939,1054,1076]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
and, in our molecular analyses, the clade falls into a polytomy with several other major groups of heterodont bivalves (
<figureCitation id="13492A6DFFE40624AA1CFBB8FB6F8072" box="[1096,1163,1115,1138]" captionStart="Figure 2" captionStartId="3.[162,240,1657,1676]" captionTargetBox="[162,1442,195,1624]" captionTargetId="figure-157@3.[162,1442,194,1624]" captionTargetPageId="3" captionText="Figure 2. Molecular phylogeny of heterodont and palaeoheterodont bivalves produced by Bayesian analysis of partial sequences from the 18SrRNA gene. Branches with posterior probabilities &lt;85% have been collapsed. Nodal support is posterior probability/bootstrap (Neighbour-joining using Maximum Likelihood distance, 10 000 reps). Details of taxa and methods in Taylor et al., 2005." figureDoi="http://doi.org/10.5281/zenodo.4687489" httpUri="https://zenodo.org/record/4687489/files/figure.png" pageId="5" pageNumber="426">Fig. 2</figureCitation>
).
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE40624ADDDFB4EFC1B80EB" pageId="5" pageNumber="426" type="multiple">
<paragraph id="8BCD36E8FFE40624ADDDFB4EFAB780C5" blockId="5.[905,1363,1197,1221]" box="[905,1363,1197,1221]" pageId="5" pageNumber="426">
RELATIONSHIPS WITHIN THE 
<taxonomicName id="4C724D6BFFE40624AA81FB4EFAB780C5" box="[1237,1363,1197,1221]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">LUCINIDAE</taxonomicName>
</paragraph>
<paragraph id="8BCD36E8FFE40624AD6EFB35FC1B80EB" blockId="5.[826,1442,1238,1904]" box="[826,1023,1238,1259]" pageId="5" pageNumber="426">
<emphasis id="B906EAFAFFE40624AD6EFB35FC1B80EB" box="[826,1023,1238,1259]" italics="true" pageId="5" pageNumber="426">Previous analyses</emphasis>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE40626AD6EFB16FC3385CF" lastPageId="7" lastPageNumber="428" pageId="5" pageNumber="426" type="discussion">
<paragraph id="8BCD36E8FFE40624AD6EFB16FBD3821F" blockId="5.[826,1442,1238,1904]" pageId="5" pageNumber="426">
In the first major review of 
<taxonomicName id="4C724D6BFFE40624AA39FB16FA8C810B" authority=", Dall (1901)" authorityName=", Dall" authorityYear="1901" box="[1133,1384,1269,1291]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">
Lucinidae, 
<bibRefCitation id="EFE34B19FFE40624AABEFB16FA8C810B" author="Dall WH" box="[1258,1384,1269,1291]" pageId="5" pageNumber="426" pagination="779 - 833" refId="ref8711" refString="Dall WH. 1901. Synopsis of the Lucinacea and of the American species. Proceedings of the United States National Museum 23: 779 - 833." type="journal article" year="1901">Dall (1901)</bibRefCitation>
</taxonomicName>
classified all 
<taxonomicName id="4C724D6BFFE40624ADF2FAF0FBF38129" authorityName=", Dall" authorityYear="1901" box="[934,1047,1299,1321]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
into six genera: 
<taxonomicName id="4C724D6BFFE40624AA88FAF0FADF8128" authorityName="Scopoli" authorityYear="1777" box="[1244,1339,1299,1320]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE40624AA88FAF0FADF8128" box="[1244,1339,1299,1320]" italics="true" pageId="5" pageNumber="426">Codakia</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE40624AB1FFAF7FA7F8129" box="[1355,1435,1300,1321]" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE40624AB1FFAF7FA7F8129" box="[1355,1435,1300,1321]" italics="true" pageId="5" pageNumber="426">Lucina</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE40624AD6EFAD0FC6A8148" baseAuthorityName="Southward" baseAuthorityYear="1986" box="[826,910,1331,1352]" class="Bivalvia" family="Lucinidae" genus="Loripes" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE40624AD6EFAD0FC6A8148" box="[826,910,1331,1352]" italics="true" pageId="5" pageNumber="426">Loripes</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE40624ADCAFAD0FC0A8148" box="[926,1006,1331,1352]" class="Bivalvia" family="Lucinidae" genus="Myrtea" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE40624ADCAFAD0FC0A8148" box="[926,1006,1331,1352]" italics="true" pageId="5" pageNumber="426">Myrtea</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE40624ADA9FAD1FB8B8147" box="[1021,1135,1330,1351]" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE40624ADA9FAD1FB8B8147" box="[1021,1135,1330,1351]" italics="true" pageId="5" pageNumber="426">Phacoides</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE40624AAFAFAD1FAC88147" baseAuthorityName="Gros, Frenkiel &amp; Felbeck" baseAuthorityYear="2000" box="[1198,1324,1330,1351]" class="Bivalvia" family="Lucinidae" genus="Divaricella" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE40624AAFAFAD1FAC88147" box="[1198,1324,1330,1351]" italics="true" pageId="5" pageNumber="426">Divaricella</emphasis>
</taxonomicName>
, with further divisions into subgenera and sections. Although there were no explicit statements of relationship, the inclusion of subgenera and sections within the genera reflected such ideas. A separate family, Corbiidae, contained 
<taxonomicName id="4C724D6BFFE40624ADC0FA28FC1581E0" box="[916,1009,1483,1504]" class="Bivalvia" family="Lucinidae" genus="Fimbria" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE40624ADC0FA28FC1581E0" box="[916,1009,1483,1504]" italics="true" pageId="5" pageNumber="426">Fimbria</emphasis>
</taxonomicName>
. Later, 
<bibRefCitation id="EFE34B19FFE40624AA0FFA2FFB1181E1" author="Lamy E" box="[1115,1269,1483,1505]" pageId="5" pageNumber="426" pagination="71 - 388" refId="ref9661" refString="Lamy E. 1920. Revision des Lucinacea vivants du Museum d'Histoire Naturelle de Paris. Journal de Conchyliologie 65: 71 - 388." type="journal article" year="1920">Lamy (1920)</bibRefCitation>
reviewed the Recent species of 
<taxonomicName id="4C724D6BFFE40624ADAAFA09FB8B8200" authorityName=", Dall" authorityYear="1901" box="[1022,1135,1514,1536]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
but made no explicit statements of relationship.
</paragraph>
<paragraph id="8BCD36E8FFE40627AD07F9C4FDF0825C" blockId="5.[826,1442,1238,1904]" lastBlockId="6.[142,758,1514,1904]" lastPageId="6" lastPageNumber="427" pageId="5" pageNumber="426">
The first comprehensive study of Recent and fossil 
<taxonomicName id="4C724D6BFFE40624AD6EF9A5FC2C825B" authority="to" authorityName="TO" box="[826,968,1606,1628]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="5" pageNumber="426" phylum="Mollusca" rank="family">Lucinidae to</taxonomicName>
develop ideas of relationship and phylogeny was that of 
<bibRefCitation id="EFE34B19FFE40624AA52F986FB48827B" author="Chavan A" box="[1030,1196,1637,1659]" pageId="5" pageNumber="426" pagination="215 - 241" refId="ref8523" refString="Chavan A. 1937 - 38. Essai critique de classification des lucines. Journal de Conchyliologie 81: 237 - 281, 82: 215 - 241." type="journal article" year="1937">Chavan (1937</bibRefCitation>
–38). The latter concluded with a geological range chart of the Recent and fossil lucinid genera, grouped according to his ideas of relationship. A cladogram derived from Chavan’s diagram and including Recent genera only is shown in 
<figureCitation id="13492A6DFFE40624AD6EF91DFC788314" box="[826,924,1790,1812]" captionStart="Figure 5" captionStartId="6.[142,220,1369,1388]" captionTargetBox="[146,754,194,1337]" captionTargetId="figure-359@6.[146,756,194,1337]" captionTargetPageId="6" captionText="Figure 5. Tree of lucinid relationships derived from final figure (tableau chronologique de l’evolution des lucines) by Chavan, 1937−1938), including living taxa only." figureDoi="http://doi.org/10.5281/zenodo.4687499" httpUri="https://zenodo.org/record/4687499/files/figure.png" pageId="5" pageNumber="426">Figure 5</figureCitation>
. By the time of the publication of the 
<taxonomicName id="4C724D6BFFE40624AB16F91DFA458314" authorityName="Linnaeus" authorityYear="1758" box="[1346,1441,1790,1812]" class="Bivalvia" higherTaxonomySource="GBIF" kingdom="Animalia" pageId="5" pageNumber="426" phylum="Mollusca" rank="class">Bivalvia</taxonomicName>
volume of the 
<emphasis id="B906EAFAFFE40624ADB6F8FEFA7F8332" box="[994,1435,1821,1842]" italics="true" pageId="5" pageNumber="426">Treatise on Invertebrate Palaeontology</emphasis>
, 
<bibRefCitation id="EFE34B19FFE40624AD6EF8D8FC028351" author="Chavan A" box="[826,998,1851,1873]" pageId="5" pageNumber="426" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan (1969)</bibRefCitation>
had somewhat revised his ideas and divided the lucinid genera into four subfamilies, 
<taxonomicName id="4C724D6BFFE70627AEDAFA09FEE68200" authorityName="J.Fleming" authorityYear="1828" box="[142,258,1514,1536]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="subFamily" subFamily="Lucininae">Lucininae</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE70627AF46FA09FE6E8200" authorityName="Chavan" authorityYear="1969" box="[274,394,1514,1536]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="subFamily" subFamily="Myrteinae">Myrteinae</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE70627AFCFFA09FDEF8200" authorityName="Chavan" authorityYear="1969" box="[411,523,1514,1536]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="subFamily" subFamily="Milthinae">Milthinae</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE70627AC1AFA09FD168200" authorityName="Gilbert" authorityYear="1967" box="[590,754,1514,1536]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="subFamily" subFamily="Divaricellinae">Divaricellinae</taxonomicName>
, with the 
<taxonomicName id="4C724D6BFFE70627AEACF9EBFE93821E" box="[248,375,1544,1566]" class="Bivalvia" family="Fimbriidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="6" pageNumber="427" phylum="Mollusca" rank="family">Fimbriidae</taxonomicName>
as a separate family. A tree constructed from this classification, but including Recent genera only, is shown in 
<figureCitation id="13492A6DFFE70627AFF8F9A5FDF5825C" box="[428,529,1606,1628]" captionStart="Figure 6" captionStartId="6.[806,884,956,975]" captionTargetBox="[810,1418,193,924]" captionTargetId="figure-386@6.[810,1418,193,924]" captionTargetPageId="6" captionText="Figure 6. Tree summarizing Chavan’s (1969) ideas of relationships in Lucinidae derived from his subfamilial classification of genera. Recent taxa only included." figureDoi="http://doi.org/10.5281/zenodo.4687495" httpUri="https://zenodo.org/record/4687495/files/figure.png" pageId="6" pageNumber="427">Figure 6</figureCitation>
.
</paragraph>
<caption id="DF0D6660FFE70627AD72FC5FFADA800A" ID-DOI="http://doi.org/10.5281/zenodo.4687495" ID-Zenodo-Dep="4687495" httpUri="https://zenodo.org/record/4687495/files/figure.png" pageId="6" pageNumber="427" startId="6.[806,884,956,975]" targetBox="[810,1418,193,924]" targetPageId="6">
<paragraph id="8BCD36E8FFE70627AD72FC5FFADA800A" blockId="6.[806,1422,956,1034]" pageId="6" pageNumber="427">
<emphasis id="B906EAFAFFE70627AD72FC5FFC6A87CF" bold="true" box="[806,910,956,975]" pageId="6" pageNumber="427">Figure 6.</emphasis>
Tree summarizing 
<bibRefCitation id="EFE34B19FFE70627AA20FC5FFAC187CF" author="Chavan A" box="[1140,1317,956,975]" pageId="6" pageNumber="427" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan’s (1969)</bibRefCitation>
ideas of relationships in 
<taxonomicName id="4C724D6BFFE70627AD89FC39FBA187ED" box="[989,1093,986,1005]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
derived from his subfamilial classification of genera. Recent taxa only included.
</paragraph>
</caption>
<caption id="DF0D6660FFE70627AEDAFABAFD6281A7" ID-DOI="http://doi.org/10.5281/zenodo.4687499" ID-Zenodo-Dep="4687499" httpUri="https://zenodo.org/record/4687499/files/figure.png" pageId="6" pageNumber="427" startId="6.[142,220,1369,1388]" targetBox="[146,754,194,1337]" targetPageId="6">
<paragraph id="8BCD36E8FFE70627AEDAFABAFD6281A7" blockId="6.[142,757,1369,1448]" pageId="6" pageNumber="427">
<emphasis id="B906EAFAFFE70627AEDAFABAFF12816D" bold="true" box="[142,246,1369,1389]" pageId="6" pageNumber="427">Figure 5.</emphasis>
Tree of lucinid relationships derived from final figure (tableau chronologique de l’evolution des lucines) by 
<bibRefCitation id="EFE34B19FFE70627AEDAFA77FEFA81A7" author="Chavan A" box="[142,286,1428,1447]" pageId="6" pageNumber="427" pagination="215 - 241" refId="ref8523" refString="Chavan A. 1937 - 38. Essai critique de classification des lucines. Journal de Conchyliologie 81: 237 - 281, 82: 215 - 241." type="journal article" year="1937">Chavan, 1937</bibRefCitation>
−1938), including living taxa only.
</paragraph>
</caption>
<paragraph id="8BCD36E8FFE70627AEF3F987FB238147" blockId="6.[142,758,1514,1904]" lastBlockId="6.[806,1422,1115,1904]" pageId="6" pageNumber="427">
Subsequently, 
<bibRefCitation id="EFE34B19FFE70627AF19F987FE1C827A" author="Bretsky SS" box="[333,504,1636,1658]" pageId="6" pageNumber="427" pagination="5 - 23" refId="ref8361" refString="Bretsky SS. 1970. Phenetic and phylogenetic classifications of the Lucinidae (Mollusca, Bivalvia). Bulletin of the Geological Institute of the University of Uppsala New Series 2: 5 - 23." type="book chapter" year="1970">Bretsky (1970)</bibRefCitation>
attempted a phenetic analysis of 
<taxonomicName id="4C724D6BFFE70627AF45F960FE668299" box="[273,386,1667,1689]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
largely using Recent and Cenozoic species from North America. For each of 42 species, she scored 42 shell characters, with up to five states recognized for each character. Considerable attention was paid to some shell features – for instance, the lunule was analysed as five separate characters with 16 states. Her resulting phenetic analysis classified the lucinids into seven groups that she called genera further divided into many subgenera. Subsequently, these phenetic results were combined with data from fossil lineages and used to produce a series of phylogenetic trees and a new classification with no suprageneric categories (
<bibRefCitation id="EFE34B19FFE70627AB7AFB35FCBB810A" author="Bretsky SS" pageId="6" pageNumber="427" pagination="219 - 337" refId="ref8397" refString="Bretsky SS. 1976. Evolution and classification of the Lucinidae (Mollusca; Bivalvia). Palaeontographica Americana 8: 219 - 337." type="journal article" year="1976">Bretsky, 1976</bibRefCitation>
), again largely based on North American taxa. A cladogram derived from Bretsky’s trees and using only Recent genera is shown in 
<figureCitation id="13492A6DFFE70627AA0BFAD1FB208147" box="[1119,1220,1330,1352]" captionStart="Figure 7" captionStartId="7.[162,240,1191,1210]" captionTargetBox="[166,774,207,1159]" captionTargetId="figure-556@7.[166,774,207,1159]" captionTargetPageId="7" captionText="Figure 7. Composite tree of lucinid relationships derived from Bretsky (1976: figs 3–9) and including living taxa only." figureDoi="http://doi.org/10.5281/zenodo.4687503" httpUri="https://zenodo.org/record/4687503/files/figure.png" pageId="6" pageNumber="427">Figure 7</figureCitation>
.
</paragraph>
<paragraph id="8BCD36E8FFE70627AD6BFAB2FB7D82D6" blockId="6.[806,1422,1115,1904]" pageId="6" pageNumber="427">
It is difficult to compare these phylogenies, as different taxa were discussed by Chavan and Bretsky, but two examples illustrate conflicts between the classifications. In 1938, Chavan thought that 
<taxonomicName id="4C724D6BFFE70627AB43FA4FFA6981C1" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[1303,1421,1452,1473]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE70627AB43FA4FFA6981C1" box="[1303,1421,1452,1473]" italics="true" pageId="6" pageNumber="427">Anodontia</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE70627AD35FA28FC1C81E0" authorityName="Stewart" authorityYear="1930" box="[865,1016,1483,1504]" class="Bivalvia" family="Lucinidae" genus="Pegophysema" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE70627AD35FA28FC1C81E0" box="[865,1016,1483,1504]" italics="true" pageId="6" pageNumber="427">Pegophysema</emphasis>
</taxonomicName>
were related to 
<taxonomicName id="4C724D6BFFE70627AA82FA28FAB781E0" authorityName="P.Fischer" authorityYear="1887" box="[1238,1363,1483,1504]" class="Bivalvia" family="Lucinidae" genus="Cavilucina" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE70627AA82FA28FAB781E0" box="[1238,1363,1483,1504]" italics="true" pageId="6" pageNumber="427">Cavilucina</emphasis>
</taxonomicName>
and 
<emphasis id="B906EAFAFFE70627AD72FA09FC4281FF" box="[806,934,1514,1535]" italics="true" pageId="6" pageNumber="427">
<taxonomicName id="4C724D6BFFE70627AD72FA09FC4681FF" authorityName="Iredale" authorityYear="1930" box="[806,930,1514,1535]" class="Bivalvia" family="Lucinidae" genus="Monitilora" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="genus">Monitilora</taxonomicName>
,
</emphasis>
but in 1969 he placed the former two genera in his subfamily 
<taxonomicName id="4C724D6BFFE70627AA44F9EBFB64821E" authorityName="Chavan" authorityYear="1969" box="[1040,1152,1544,1566]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="subFamily" subFamily="Milthinae">Milthinae</taxonomicName>
and the latter two genera into the 
<taxonomicName id="4C724D6BFFE70627ADEBF9C4FBDC823D" authorityName="Chavan" authorityYear="1969" box="[959,1080,1575,1597]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="subFamily" subFamily="Myrteinae">Myrteinae</taxonomicName>
. By contrast, 
<bibRefCitation id="EFE34B19FFE70627AAB5F9C4FA6A823D" author="Bretsky SS" box="[1249,1422,1575,1597]" pageId="6" pageNumber="427" pagination="219 - 337" refId="ref8397" refString="Bretsky SS. 1976. Evolution and classification of the Lucinidae (Mollusca; Bivalvia). Palaeontographica Americana 8: 219 - 337." type="journal article" year="1976">Bretsky (1976)</bibRefCitation>
indicated a relationship between 
<taxonomicName id="4C724D6BFFE70627AA8CF9A5FAAA825B" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[1240,1358,1606,1627]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE70627AA8CF9A5FAAA825B" box="[1240,1358,1606,1627]" italics="true" pageId="6" pageNumber="427">Anodontia</emphasis>
</taxonomicName>
and 
<emphasis id="B906EAFAFFE70627AD72F986FC99827A" box="[806,893,1637,1658]" italics="true" pageId="6" pageNumber="427">
<taxonomicName id="4C724D6BFFE70627AD72F986FC9D827A" box="[806,889,1637,1658]" class="Bivalvia" family="Lucinidae" genus="Myrtea" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="genus">Myrtea</taxonomicName>
,
</emphasis>
or in an alternative scenario, with 
<taxonomicName id="4C724D6BFFE70627AB67F986FA63827A" baseAuthorityName="Southward" baseAuthorityYear="1986" box="[1331,1415,1637,1658]" class="Bivalvia" family="Lucinidae" genus="Loripes" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE70627AB67F986FA63827A" box="[1331,1415,1637,1658]" italics="true" pageId="6" pageNumber="427">Loripes</emphasis>
</taxonomicName>
. Similarly, 
<bibRefCitation id="EFE34B19FFE70627ADF0F960FBB18299" author="Chavan A" box="[932,1109,1667,1689]" pageId="6" pageNumber="427" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan (1969)</bibRefCitation>
placed 
<taxonomicName id="4C724D6BFFE70627AAEBF967FAD58299" authorityName="Dall" authorityYear="1901" box="[1215,1329,1668,1689]" class="Bivalvia" family="Lucinidae" genus="Lucinoma" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE70627AAEBF967FAD58299" box="[1215,1329,1668,1689]" italics="true" pageId="6" pageNumber="427">Lucinoma</emphasis>
</taxonomicName>
in the 
<taxonomicName id="4C724D6BFFE70627AD72F941FC7A82B8" authorityName="Chavan" authorityYear="1969" box="[806,926,1698,1720]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="subFamily" subFamily="Myrteinae">Myrteinae</taxonomicName>
, but 
<bibRefCitation id="EFE34B19FFE70627ADBDF941FB7F82B8" author="Bretsky SS" box="[1001,1179,1698,1720]" pageId="6" pageNumber="427" pagination="219 - 337" refId="ref8397" refString="Bretsky SS. 1976. Evolution and classification of the Lucinidae (Mollusca; Bivalvia). Palaeontographica Americana 8: 219 - 337." type="journal article" year="1976">Bretsky (1976)</bibRefCitation>
thought the genus related to 
<taxonomicName id="4C724D6BFFE70627ADCAF923FC0882D5" authorityName="H.Adams &amp; A.Adams" authorityYear="1857" box="[926,1004,1728,1749]" class="Bivalvia" family="Lucinidae" genus="Miltha" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE70627ADCAF923FC0882D5" box="[926,1004,1728,1749]" italics="true" pageId="6" pageNumber="427">Miltha</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE70627AA73F923FB7582D5" authorityName="Cossmann" authorityYear="1912" box="[1063,1169,1728,1749]" class="Bivalvia" family="Lucinidae" genus="Eomiltha" kingdom="Animalia" order="Lucinoida" pageId="6" pageNumber="427" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE70627AA73F923FB7582D5" box="[1063,1169,1728,1749]" italics="true" pageId="6" pageNumber="427">Eomiltha</emphasis>
</taxonomicName>
.
</paragraph>
<paragraph id="8BCD36E8FFE70626AD6BF93CFEEB8370" blockId="6.[806,1422,1115,1904]" lastBlockId="7.[162,778,1360,1904]" lastPageId="7" lastPageNumber="428" pageId="6" pageNumber="427">
All these previous studies were based entirely on shell characters, the conflicting hypotheses probably resulting from high levels of homoplasy. Many lucinids have relatively smooth, subcircular, discoidal shells with minimal shell sculpture. Moreover, hinge teeth are often reduced or in many instances entirely absent. Divaricate sculpture, as in 
<taxonomicName id="4C724D6BFFE60626AC62FA8CFD508184" baseAuthorityName="Gros, Frenkiel &amp; Felbeck" baseAuthorityYear="2000" box="[566,692,1391,1412]" class="Bivalvia" family="Lucinidae" genus="Divaricella" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AC62FA8CFD508184" box="[566,692,1391,1412]" italics="true" pageId="7" pageNumber="428">Divaricella</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE60626AC97FA8CFF3181A3" authorityName="Chavan" authorityYear="1951" class="Bivalvia" family="Lucinidae" genus="Divalinga" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AC97FA8CFF3181A3" italics="true" pageId="7" pageNumber="428">Divalinga</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE60626AF45FA6DFE4B81A3" authorityName="Dall" authorityYear="1901" box="[273,431,1422,1443]" class="Bivalvia" family="Lucinidae" genus="Pompholigina" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AF45FA6DFE4B81A3" box="[273,431,1422,1443]" italics="true" pageId="7" pageNumber="428">Pompholigina</emphasis>
</taxonomicName>
(
<figureCitation id="13492A6DFFE60626AFEBFA6DFDEE81A4" box="[447,522,1422,1444]" captionStart="Figure 1" captionStartId="1.[162,240,1737,1756]" captionTargetBox="[238,1366,192,1704]" captionTargetId="figure-151@1.[238,1368,192,1704]" captionTargetPageId="1" captionText="Figure 1. Diversity of form within Lucinidae. A, Plicolucina flabellata Glover, Taylor &amp; Slack-Smith, 2003, Shell length (SL) = 22 mm; B, Lamellolucina trisulcata Taylor &amp; Glover, 2002, SL = 10 mm; C, Codakia tigerina (Linnaeus, 1758), SL = 70 mm; D, Anodontia philippiana (Reeve, 1850), SL = 66 mm; E, Miltha childrenae (Gray 1825), SL = 82 mm; F, Eomiltha voorhoevi, SL = 80 mm; G, Austriella corrugata (Deshayes, 1843), SL = 60 mm; H, Ctena bella (Conrad, 1837), SL = 25 mm; I, Rasta lamyi (Abrard, 1942), SL = 30 mm; J, Pompholigina gibba (Gray, 1825), SL = 27 mm; K, Myrtea spinifera (Montagu, 1803), SL = 26 mm." figureDoi="http://doi.org/10.5281/zenodo.4687487" httpUri="https://zenodo.org/record/4687487/files/figure.png" pageId="7" pageNumber="428">Fig. 1J</figureCitation>
) and used by 
<bibRefCitation id="EFE34B19FFE60626ACE5FA6DFF0E81C2" author="Chavan A" pageId="7" pageNumber="428" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan (1969)</bibRefCitation>
to define the 
<taxonomicName id="4C724D6BFFE60626AFE2FA4FFDB281C2" authorityName="Gilbert" authorityYear="1967" box="[438,598,1452,1474]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="subFamily" subFamily="Divaricellinae">Divaricellinae</taxonomicName>
has probably evolved independently in different clades (
<bibRefCitation id="EFE34B19FFE60626ACC2FA28FEC38200" author="Dekker H &amp; Goud J" pageId="7" pageNumber="428" pagination="115 - 136" refId="ref8816" refString="Dekker H, Goud J. 1994. Review of the living Indo-West- Pacific species of. Divaricella sens auct. With descriptions of two new species and a summary of species from other regions. Vita Marina 42: 115 - 136." type="journal article" year="1994">Dekker &amp; Goud, 1994</bibRefCitation>
). Recent molecular evidence is confirming that the 
<taxonomicName id="4C724D6BFFE60626AF57F9EBFE47821E" authorityName="Gilbert" authorityYear="1967" box="[259,419,1544,1566]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="subFamily" subFamily="Divaricellinae">Divaricellinae</taxonomicName>
is paraphyletic, with, for example, 
<taxonomicName id="4C724D6BFFE60626AE82F9C4FD76823D" authority="(Linnaeus, 1758)" baseAuthorityName="Linnaeus" baseAuthorityYear="1758" box="[214,658,1575,1597]" class="Bivalvia" family="Lucinidae" genus="Lucinella" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="species" species="divaricata">
<emphasis id="B906EAFAFFE60626AE82F9C4FE25823C" box="[214,449,1575,1596]" italics="true" pageId="7" pageNumber="428">Lucinella divaricata</emphasis>
(Linnaeus, 1758)
</taxonomicName>
identified as part of the 
<taxonomicName id="4C724D6BFFE60626AF6AF9A5FE76825B" baseAuthorityName="Southward" baseAuthorityYear="1986" box="[318,402,1606,1627]" class="Bivalvia" family="Lucinidae" genus="Loripes" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AF6AF9A5FE76825B" box="[318,402,1606,1627]" italics="true" pageId="7" pageNumber="428">Loripes</emphasis>
</taxonomicName>
group (J. D. Taylor, S. T. Williams &amp; E. A. Glover, unpubl. data). We previously considered (
<bibRefCitation id="EFE34B19FFE60626AEB7F960FE048299" author="Glover EA &amp; Taylor JD" box="[227,480,1667,1689]" pageId="7" pageNumber="428" pagination="263 - 292" refId="ref9176" refString="Glover EA, Taylor JD. 2001. Systematic revision of Australian and Indo-Pacific Lucinidae (Mollusca: Bivalvia): Pillucina, Wallucina and descriptions of two new genera and four new species. Records of the Australian Museum 53: 263 - 292." type="journal article" year="2001">Glover &amp; Taylor, 2001</bibRefCitation>
) an obliquely inset, internal ligament as a possible apomorphic character of a group of genera around 
<taxonomicName id="4C724D6BFFE60626AF91F922FDFD82D6" baseAuthorityName="Southward" baseAuthorityYear="1986" box="[453,537,1729,1750]" class="Bivalvia" family="Lucinidae" genus="Loripes" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AF91F922FDFD82D6" box="[453,537,1729,1750]" italics="true" pageId="7" pageNumber="428">Loripes</emphasis>
</taxonomicName>
, including 
<taxonomicName id="4C724D6BFFE60626ACF5F923FCEE82D5" authorityName="Pilsbry" authorityYear="1921" box="[673,778,1728,1749]" class="Bivalvia" family="Lucinidae" genus="Pillucina" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626ACF5F923FCEE82D5" box="[673,778,1728,1749]" italics="true" pageId="7" pageNumber="428">Pillucina</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE60626AE87F93CFEA382F4" authorityName="Iredale" authorityYear="1930" box="[211,327,1759,1780]" class="Bivalvia" family="Lucinidae" genus="Wallucina" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AE87F93CFEA382F4" box="[211,327,1759,1780]" italics="true" pageId="7" pageNumber="428">Wallucina</emphasis>
</taxonomicName>
. However, a similarly inset internal ligament occurs in several species of the 
<taxonomicName id="4C724D6BFFE60626ACC7F91DFCED8313" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[659,777,1790,1811]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626ACC7F91DFCED8313" box="[659,777,1790,1811]" italics="true" pageId="7" pageNumber="428">Anodontia</emphasis>
</taxonomicName>
clade, including 
<taxonomicName id="4C724D6BFFE60626AF0BF8FEFDE78331" box="[351,515,1820,1842]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="species" species="philippiana">
<emphasis id="B906EAFAFFE60626AF0BF8FEFDE78331" box="[351,515,1820,1842]" italics="true" pageId="7" pageNumber="428">A. philippiana</emphasis>
</taxonomicName>
and 
<emphasis id="B906EAFAFFE60626AC6BF8FEFD468332" box="[575,674,1821,1842]" italics="true" pageId="7" pageNumber="428">
<taxonomicName id="4C724D6BFFE60626AC6BF8FEFD7A8332" baseAuthorityName="Reeve" baseAuthorityYear="1850" box="[575,670,1821,1842]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="species" species="ovum">A. ovum</taxonomicName>
,
</emphasis>
suggesting an independent derivation of this form of ligament.
</paragraph>
<paragraph id="8BCD36E8FFE60626AD07FF20FC3385CF" blockId="7.[826,1442,195,463]" pageId="7" pageNumber="428">Shell characters have important potential in phylogenetic analysis and their use is essential if fossil taxa are to be integrated into phylogenetic schemes. However, rigorous analysis of ligament structure, anterior muscle scars, ribbing structure, hinge teeth and shell microstructure is almost entirely lacking. At present shell characters are useful in discrimination of species and genera but give little information on relationships.</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE60626ADA6FDE8FB0E8621" box="[1010,1258,523,547]" pageId="7" pageNumber="428" type="multiple">
<paragraph id="8BCD36E8FFE60626ADA6FDE8FB0E8621" blockId="7.[1010,1258,523,547]" box="[1010,1258,523,547]" pageId="7" pageNumber="428">MOLECULAR RESULTS</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE60626AD6EFDD0FBA38701" pageId="7" pageNumber="428" type="description">
<paragraph id="8BCD36E8FFE60626AD6EFDD0FBA38701" blockId="7.[826,1442,563,769]" pageId="7" pageNumber="428">
<bibRefCitation id="EFE34B19FFE60626AD6EFDD0FBD28649" author="Williams ST &amp; Taylor JD &amp; Glover EA" box="[826,1078,563,585]" pageId="7" pageNumber="428" pagination="187 - 202" refId="ref10661" refString="Williams ST, Taylor JD, Glover EA. 2004. Molecular phylogeny of the Lucinoidea (Bivalvia): non-monophyly and separate acquisition of bacterial chemosymbiosis. Journal of Molluscan Studies 70: 187 - 202." type="journal article" year="2004">
Williams 
<emphasis id="B906EAFAFFE60626ADF8FDD7FC398648" box="[940,989,563,585]" italics="true" pageId="7" pageNumber="428">et al</emphasis>
. (2004)
</bibRefCitation>
presented the first significant molecular analysis of relationships within the 
<taxonomicName id="4C724D6BFFE60626AD6EFD92FC4A8687" box="[826,942,625,647]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
. Sequences of 18S and 28S rRNA genes were obtained from 32 species representing 21 genera from around the world. This initial phylogeny recognized a number of major clades (
<figureCitation id="13492A6DFFE60626AAE0FD2EFB1086E3" box="[1204,1268,717,739]" captionStart="Figure 3" captionStartId="4.[142,220,939,958]" captionTargetBox="[142,1422,195,907]" captionTargetId="figure-297@4.[142,1422,194,907]" captionTargetPageId="4" captionText="Figure 3. Molecular phylogeny of Lucinidae (from Williams et al., 2004) based on concatenated gene sequence data from 18S rRNA and 28S rRNA genes. Branches collapsed with posterior probabilities of&gt; 90%. Nodal support is posterior probability/bootstrap (NJ using ML distance, 10 000 reps). *Bootstrap support is 96% for lucinid clade B excluding Phacoides pectinatus." figureDoi="http://doi.org/10.5281/zenodo.4687491" httpUri="https://zenodo.org/record/4687491/files/figure.png" pageId="7" pageNumber="428">Fig. 3</figureCitation>
) and these are briefly discussed below.
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE60626AD6EFCABFC2E875C" box="[826,970,839,861]" pageId="7" pageNumber="428" type="multiple">
<paragraph id="8BCD36E8FFE60626AD6EFCABFC2E875C" blockId="7.[826,1442,839,1291]" box="[826,970,839,861]" pageId="7" pageNumber="428">
<emphasis id="B906EAFAFFE60626AD6EFCABFC2E875C" box="[826,970,839,861]" italics="true" pageId="7" pageNumber="428">
<taxonomicName id="4C724D6BFFE60626AD6EFCABFC6C875D" box="[826,904,840,861]" class="Bivalvia" family="Lucinidae" genus="Myrtea" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">Myrtea</taxonomicName>
clade
</emphasis>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE60626AD6EFC85FC43810B" pageId="7" pageNumber="428" type="discussion">
<paragraph id="8BCD36E8FFE60626AD6EFC85FC43810B" blockId="7.[826,1442,839,1291]" pageId="7" pageNumber="428">
The two species sequenced, 
<taxonomicName id="4C724D6BFFE60626AADBFC84FC25879B" authority="(Montagu, 1803)" baseAuthorityName="Montagu" baseAuthorityYear="1803" class="Bivalvia" family="Lucinidae" genus="Myrtea" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="species" species="spinifera">
<emphasis id="B906EAFAFFE60626AADBFC84FAB5877B" box="[1167,1361,870,892]" italics="true" pageId="7" pageNumber="428">Myrtea spinifera</emphasis>
(Montagu, 1803)
</taxonomicName>
from Europe and 
<taxonomicName id="4C724D6BFFE60626AAF9FC66FC0587B9" authority="(Hedley, 1918)" baseAuthorityName="Hedley" baseAuthorityYear="1918" class="Bivalvia" family="Lucinidae" genus="Notomyrtea" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="species" species="botanica">
<emphasis id="B906EAFAFFE60626AAF9FC66FA45879A" box="[1197,1441,901,922]" italics="true" pageId="7" pageNumber="428">Notomyrtea botanica</emphasis>
(Hedley, 1918)
</taxonomicName>
from 
<collectingCountry id="F3657678FFE60626AA7BFC40FB7987B9" box="[1071,1181,931,953]" name="Australia" pageId="7" pageNumber="428">Australia</collectingCountry>
, form a monophyletic clade. Species in the 
<emphasis id="B906EAFAFFE60626AA6CFC20FB5787D7" box="[1080,1203,962,984]" italics="true" pageId="7" pageNumber="428">
<taxonomicName id="4C724D6BFFE60626AA6CFC20FB6C87D8" box="[1080,1160,963,984]" class="Bivalvia" family="Lucinidae" genus="Myrtea" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus" sensu="lato">Myrtea</taxonomicName>
<taxonomicNameLabel id="A2355781FFE60626AAC0FC21FB5787D7" box="[1172,1203,962,983]" pageId="7" pageNumber="428" sensu="lato">s.l.</taxonomicNameLabel>
</emphasis>
group usually have rather flat elongate shells, prominent commarginal lamellae, spinose dorsal margins, small teeth and short anterior adductor muscles. The clade is diverse in offshore habitats where there are many undescribed species. 
<bibRefCitation id="EFE34B19FFE60626ADADFBB8FB428071" author="Chavan A" box="[1017,1190,1115,1137]" pageId="7" pageNumber="428" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan (1969)</bibRefCitation>
included five Recent genera (synonymizing 
<taxonomicName id="4C724D6BFFE60626AA10FB98FB2C8090" authorityName="Iredale" authorityYear="1924" box="[1092,1224,1147,1168]" class="Bivalvia" family="Lucinidae" genus="Notomyrtea" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AA10FB98FB2C8090" box="[1092,1224,1147,1168]" italics="true" pageId="7" pageNumber="428">Notomyrtea</emphasis>
</taxonomicName>
within 
<taxonomicName id="4C724D6BFFE60626AB7CFB98FA9C8090" box="[1320,1400,1147,1168]" class="Bivalvia" family="Lucinidae" genus="Myrtea" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AB7CFB98FA9C8090" box="[1320,1400,1147,1168]" italics="true" pageId="7" pageNumber="428">Myrtea</emphasis>
</taxonomicName>
) in the new subfamily 
<taxonomicName id="4C724D6BFFE60626AA7CFB7AFB4580AF" authorityName="Chavan" authorityYear="1969" box="[1064,1185,1177,1199]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="subFamily" subFamily="Myrteinae">Myrteinae</taxonomicName>
, but his inclusion of 
<taxonomicName id="4C724D6BFFE60626AD6EFB5BFC4880CD" authorityName="Dall" authorityYear="1901" box="[826,940,1208,1229]" class="Bivalvia" family="Lucinidae" genus="Lucinoma" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AD6EFB5BFC4880CD" box="[826,940,1208,1229]" italics="true" pageId="7" pageNumber="428">Lucinoma</emphasis>
</taxonomicName>
is not supported by our molecular results and three of the other genera have not yet been analysed.
</paragraph>
</subSubSection>
<caption id="DF0D6660FFE60626AEF6FB44FCEF80D8" ID-DOI="http://doi.org/10.5281/zenodo.4687503" ID-Zenodo-Dep="4687503" httpUri="https://zenodo.org/record/4687503/files/figure.png" pageId="7" pageNumber="428" startId="7.[162,240,1191,1210]" targetBox="[166,774,207,1159]" targetPageId="7">
<paragraph id="8BCD36E8FFE60626AEF6FB44FCEF80D8" blockId="7.[162,779,1191,1240]" pageId="7" pageNumber="428">
<emphasis id="B906EAFAFFE60626AEF6FB44FEEE80BB" bold="true" box="[162,266,1191,1211]" pageId="7" pageNumber="428">Figure 7.</emphasis>
Composite tree of lucinid relationships derived from 
<bibRefCitation id="EFE34B19FFE60626AE8CFB26FE8980D8" author="Bretsky SS" box="[216,365,1221,1240]" pageId="7" pageNumber="428" pagination="219 - 337" refId="ref8397" refString="Bretsky SS. 1976. Evolution and classification of the Lucinidae (Mollusca; Bivalvia). Palaeontographica Americana 8: 219 - 337." type="journal article" year="1976">Bretsky (1976</bibRefCitation>
: figs 3–9) and including living taxa only.
</paragraph>
</caption>
<subSubSection id="C3686563FFE60626AD6EFAB3FC0B8165" box="[826,1007,1360,1381]" pageId="7" pageNumber="428" type="multiple">
<paragraph id="8BCD36E8FFE60626AD6EFAB3FC0B8165" blockId="7.[826,1442,1360,1904]" box="[826,1007,1360,1381]" pageId="7" pageNumber="428">
<emphasis id="B906EAFAFFE60626AD6EFAB3FC0B8165" box="[826,1007,1360,1381]" italics="true" pageId="7" pageNumber="428">
<taxonomicName id="4C724D6BFFE60626AD6EFAB3FC498165" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[826,941,1360,1381]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">Anodontia</taxonomicName>
clade
</emphasis>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE60629AD6EFA93FDDF8572" lastPageId="8" lastPageNumber="429" pageId="7" pageNumber="428" type="discussion">
<paragraph id="8BCD36E8FFE60629AD6EFA93FDDF8572" blockId="7.[826,1442,1360,1904]" lastBlockId="8.[142,758,195,371]" lastPageId="8" lastPageNumber="429" pageId="7" pageNumber="428">
Most of the 
<taxonomicName id="4C724D6BFFE60626AD9EFA8CFBA48184" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[970,1088,1391,1412]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AD9EFA8CFBA48184" box="[970,1088,1391,1412]" italics="true" pageId="7" pageNumber="428">Anodontia</emphasis>
</taxonomicName>
species analysed form a wellsupported, monophyletic clade (including West Atlantic, Mediterranean and Indo-Pacific species) distinct from other lucinids (
<figureCitation id="13492A6DFFE60626AA71FA28FB8181E1" box="[1061,1125,1483,1505]" captionStart="Figure 3" captionStartId="4.[142,220,939,958]" captionTargetBox="[142,1422,195,907]" captionTargetId="figure-297@4.[142,1422,194,907]" captionTargetPageId="4" captionText="Figure 3. Molecular phylogeny of Lucinidae (from Williams et al., 2004) based on concatenated gene sequence data from 18S rRNA and 28S rRNA genes. Branches collapsed with posterior probabilities of&gt; 90%. Nodal support is posterior probability/bootstrap (NJ using ML distance, 10 000 reps). *Bootstrap support is 96% for lucinid clade B excluding Phacoides pectinatus." figureDoi="http://doi.org/10.5281/zenodo.4687491" httpUri="https://zenodo.org/record/4687491/files/figure.png" pageId="7" pageNumber="428">Fig. 3</figureCitation>
). However, the 
<typeStatus id="54C9884AFFE60626AB4CFA2FFAAD81E1" box="[1304,1353,1484,1505]" pageId="7" pageNumber="428">type</typeStatus>
species 
<taxonomicName id="4C724D6BFFE60626AD6EFA09FB9B81FF" authority="Link, 1807" authorityName="Link" authorityYear="1807" box="[826,1151,1514,1536]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="species" species="alba">
<emphasis id="B906EAFAFFE60626AD6EFA09FC1481FF" box="[826,1008,1514,1535]" italics="true" pageId="7" pageNumber="428">Anodontia alba</emphasis>
Link, 1807
</taxonomicName>
from the West Atlantic groups with the southern Australian species 
<taxonomicName id="4C724D6BFFE60626AD6EF9C4FB02823D" authority="(Tate, 1897)" baseAuthorityName="Tate" baseAuthorityYear="1897" box="[826,1254,1575,1597]" class="Bivalvia" family="Lucinidae" genus="Pseudolucinisca" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="species" species="lacteola">
<emphasis id="B906EAFAFFE60626AD6EF9C4FBB6823C" box="[826,1106,1575,1596]" italics="true" pageId="7" pageNumber="428">Pseudolucinisca lacteola</emphasis>
(Tate, 1897)
</taxonomicName>
to form a basal sister clade to all the other 
<taxonomicName id="4C724D6BFFE60626AA26F9A5FB0C825B" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[1138,1256,1606,1627]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AA26F9A5FB0C825B" box="[1138,1256,1606,1627]" italics="true" pageId="7" pageNumber="428">Anodontia</emphasis>
</taxonomicName>
species. In shell characters 
<taxonomicName id="4C724D6BFFE60626ADEFF986FBC9827A" baseAuthorityName="Tate" baseAuthorityYear="1897" box="[955,1069,1637,1658]" class="Bivalvia" family="Lucinidae" genus="Pseudolucinisca" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="species" species="lacteola">
<emphasis id="B906EAFAFFE60626ADEFF986FBC9827A" box="[955,1069,1637,1658]" italics="true" pageId="7" pageNumber="428">P. lacteola</emphasis>
</taxonomicName>
is not similar to 
<taxonomicName id="4C724D6BFFE60626AAA8F986FA96827A" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[1276,1394,1637,1658]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AAA8F986FA96827A" box="[1276,1394,1637,1658]" italics="true" pageId="7" pageNumber="428">Anodontia</emphasis>
</taxonomicName>
but further studies of these poorly known bivalves are needed to resolve its position and the paraphyly of the 
<taxonomicName id="4C724D6BFFE60626AD6EF922FC5482D6" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[826,944,1729,1750]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AD6EF922FC5482D6" box="[826,944,1729,1750]" italics="true" pageId="7" pageNumber="428">Anodontia</emphasis>
</taxonomicName>
group. 
<taxonomicName id="4C724D6BFFE60626AA52F922FB9882D6" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[1030,1148,1729,1750]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="7" pageNumber="428" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE60626AA52F922FB9882D6" box="[1030,1148,1729,1750]" italics="true" pageId="7" pageNumber="428">Anodontia</emphasis>
</taxonomicName>
species are characterized by smooth, subspherical toothless shells and they also possess a number of distinctive anatomical features including: a mantle septum, digitiform mantle gills, a thick outer mantle fold and extensive mantle fusion ventral to the posterior apertures involving the inner and most of the middle mantle folds (Taylor &amp; Glover, 2005). 
<bibRefCitation id="EFE34B19FFE90629AE88FF01FE6284F8" author="Chavan A" box="[220,390,226,248]" pageId="8" pageNumber="429" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan (1969)</bibRefCitation>
included 
<taxonomicName id="4C724D6BFFE90629AFAEFF01FD9484F7" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[506,624,226,247]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AFAEFF01FD9484F7" box="[506,624,226,247]" italics="true" pageId="8" pageNumber="429">Anodontia</emphasis>
</taxonomicName>
in his subfamily 
<taxonomicName id="4C724D6BFFE90629AEB5FEE2FEB58517" authorityName="Chavan" authorityYear="1969" box="[225,337,257,279]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="subFamily" subFamily="Milthinae">Milthinae</taxonomicName>
but his concept of the group is not supported by the molecular analysis. Neither is there any support for 
<bibRefCitation id="EFE34B19FFE90629AF15FEDDFE1D8554" author="Bretsky SS" box="[321,505,318,340]" pageId="8" pageNumber="429" pagination="219 - 337" refId="ref8397" refString="Bretsky SS. 1976. Evolution and classification of the Lucinidae (Mollusca; Bivalvia). Palaeontographica Americana 8: 219 - 337." type="journal article" year="1976">Bretsky’s (1976)</bibRefCitation>
proposal of a relationship between 
<taxonomicName id="4C724D6BFFE90629AF7AFEBEFE408572" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[302,420,349,370]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AF7AFEBEFE408572" box="[302,420,349,370]" italics="true" pageId="8" pageNumber="429">Anodontia</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE90629AFB4FEBEFDD08572" baseAuthorityName="Southward" baseAuthorityYear="1986" box="[480,564,349,370]" class="Bivalvia" family="Lucinidae" genus="Loripes" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AFB4FEBEFDD08572" box="[480,564,349,370]" italics="true" pageId="8" pageNumber="429">Loripes</emphasis>
</taxonomicName>
.
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AEDAFE53FECF85C5" box="[142,299,432,453]" pageId="8" pageNumber="429" type="multiple">
<paragraph id="8BCD36E8FFE90629AEDAFE53FECF85C5" blockId="8.[142,757,432,547]" box="[142,299,432,453]" pageId="8" pageNumber="429">
<emphasis id="B906EAFAFFE90629AEDAFE53FECF85C5" box="[142,299,432,453]" italics="true" pageId="8" pageNumber="429">
<taxonomicName id="4C724D6BFFE90629AEDAFE53FF0D85C5" box="[142,233,432,453]" class="Bivalvia" family="Lucinidae" genus="Fimbria" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">Fimbria</taxonomicName>
clade
</emphasis>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AEDAFE2CFD7C8622" pageId="8" pageNumber="429" type="discussion">
<paragraph id="8BCD36E8FFE90629AEDAFE2CFD7C8622" blockId="8.[142,757,432,547]" pageId="8" pageNumber="429">
<taxonomicName id="4C724D6BFFE90629AEDAFE2CFDCD85E5" authority="(Linnaeus, 1758)" baseAuthorityName="Linnaeus" baseAuthorityYear="1758" box="[142,553,463,485]" class="Bivalvia" family="Lucinidae" genus="Fimbria" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="fimbriata">
<emphasis id="B906EAFAFFE90629AEDAFE2CFEBB85E4" box="[142,351,463,484]" italics="true" pageId="8" pageNumber="429">Fimbria fimbriata</emphasis>
(Linnaeus, 1758)
</taxonomicName>
groups in a polytomy with other lucinid clades. There is no support on present evidence for separate familial status.
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AEDAFD83FEDA8676" box="[142,318,608,630]" pageId="8" pageNumber="429" type="multiple">
<paragraph id="8BCD36E8FFE90629AEDAFD83FEDA8676" blockId="8.[142,758,608,937]" box="[142,318,608,630]" pageId="8" pageNumber="429">
<emphasis id="B906EAFAFFE90629AEDAFD83FEDA8676" box="[142,318,608,630]" italics="true" pageId="8" pageNumber="429">Lucinid clade A</emphasis>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AEDAFD9CFD5887A9" pageId="8" pageNumber="429" type="discussion">
<paragraph id="8BCD36E8FFE90629AEDAFD9CFD5887A9" blockId="8.[142,758,608,937]" pageId="8" pageNumber="429">
This well-supported clade contains 
<taxonomicName id="4C724D6BFFE90629AC6EFD9CFD7D8694" authorityName="Scopoli" authorityYear="1777" box="[570,665,639,660]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AC6EFD9CFD7D8694" box="[570,665,639,660]" italics="true" pageId="8" pageNumber="429">Codakia</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE90629ACF8FD63FD0B8695" box="[684,751,640,661]" class="Bivalvia" family="Lucinidae" genus="Ctena" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629ACF8FD63FD0B8695" box="[684,751,640,661]" italics="true" pageId="8" pageNumber="429">Ctena</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE90629AEDAFD7CFEE486B4" authorityName="Dall" authorityYear="1901" box="[142,256,671,692]" class="Bivalvia" family="Lucinidae" genus="Lucinoma" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AEDAFD7CFEE486B4" box="[142,256,671,692]" italics="true" pageId="8" pageNumber="429">Lucinoma</emphasis>
</taxonomicName>
species and 
<emphasis id="B906EAFAFFE90629AFC2FD7DFD6886B4" box="[406,652,670,692]" italics="true" pageId="8" pageNumber="429">
<taxonomicName id="4C724D6BFFE90629AFC2FD7DFD6C86B4" authorityName="Zorina" authorityYear="1978" box="[406,648,670,692]" class="Bivalvia" family="Lucinidae" genus="Pillucina" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="vietnamica">Pillucina vietnamica</taxonomicName>
.
</emphasis>
On shell characters 
<taxonomicName id="4C724D6BFFE90629AF58FD5EFE8F86D2" authorityName="Scopoli" authorityYear="1777" box="[268,363,701,722]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AF58FD5EFE8F86D2" box="[268,363,701,722]" italics="true" pageId="8" pageNumber="429">Codakia</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE90629AFF7FD5EFE0286D2" box="[419,486,701,722]" class="Bivalvia" family="Lucinidae" genus="Ctena" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AFF7FD5EFE0286D2" box="[419,486,701,722]" italics="true" pageId="8" pageNumber="429">Ctena</emphasis>
</taxonomicName>
have long been thought to be related (
<bibRefCitation id="EFE34B19FFE90629AF7DFD38FE2286F0" author="Chavan A" box="[297,454,731,753]" pageId="8" pageNumber="429" pagination="215 - 241" refId="ref8523" refString="Chavan A. 1937 - 38. Essai critique de classification des lucines. Journal de Conchyliologie 81: 237 - 281, 82: 215 - 241." type="journal article" year="1937">Chavan, 1937</bibRefCitation>
−38; 
<bibRefCitation id="EFE34B19FFE90629AFAFFD38FD7386F1" author="Bretsky SS" box="[507,663,731,753]" pageId="8" pageNumber="429" pagination="219 - 337" refId="ref8397" refString="Bretsky SS. 1976. Evolution and classification of the Lucinidae (Mollusca; Bivalvia). Palaeontographica Americana 8: 219 - 337." type="journal article" year="1976">Bretsky, 1976</bibRefCitation>
) but the inclusion of 
<taxonomicName id="4C724D6BFFE90629AF7EFD18FE788710" authorityName="Dall" authorityYear="1901" box="[298,412,763,784]" class="Bivalvia" family="Lucinidae" genus="Lucinoma" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AF7EFD18FE788710" box="[298,412,763,784]" italics="true" pageId="8" pageNumber="429">Lucinoma</emphasis>
</taxonomicName>
is surprising. 
<taxonomicName id="4C724D6BFFE90629AC0FFD19FD5E870F" authorityName="Scopoli" authorityYear="1777" box="[603,698,762,783]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AC0FFD19FD5E870F" box="[603,698,762,783]" italics="true" pageId="8" pageNumber="429">Codakia</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE90629AEDAFCFAFF35872E" box="[142,209,793,814]" class="Bivalvia" family="Lucinidae" genus="Ctena" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AEDAFCFAFF35872E" box="[142,209,793,814]" italics="true" pageId="8" pageNumber="429">Ctena</emphasis>
</taxonomicName>
were included by 
<bibRefCitation id="EFE34B19FFE90629AFF5FCFAFDAC872F" author="Chavan A" box="[417,584,793,815]" pageId="8" pageNumber="429" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan (1969)</bibRefCitation>
in the subfamily 
<taxonomicName id="4C724D6BFFE90629AEE1FCD4FEC3874D" authorityName="J.Fleming" authorityYear="1828" box="[181,295,823,845]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="subFamily" subFamily="Lucininae">Lucininae</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE90629AF33FCDBFE3D874D" authorityName="Dall" authorityYear="1901" box="[359,473,824,845]" class="Bivalvia" family="Lucinidae" genus="Lucinoma" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AF33FCDBFE3D874D" box="[359,473,824,845]" italics="true" pageId="8" pageNumber="429">Lucinoma</emphasis>
</taxonomicName>
in the 
<taxonomicName id="4C724D6BFFE90629AC67FCD4FD48874D" authorityName="Chavan" authorityYear="1969" box="[563,684,823,845]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="subFamily" subFamily="Myrteinae">Myrteinae</taxonomicName>
. However, all the species in the group possess only a short length of mantle fusion ventral to the posterior apertures and papillae around the inhalant opening.
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AEDAFC04FEDB87FD" box="[142,319,999,1021]" pageId="8" pageNumber="429" type="multiple">
<paragraph id="8BCD36E8FFE90629AEDAFC04FEDB87FD" blockId="8.[142,758,999,1757]" box="[142,319,999,1021]" pageId="8" pageNumber="429">
<emphasis id="B906EAFAFFE90629AEDAFC04FEDB87FD" box="[142,319,999,1021]" italics="true" pageId="8" pageNumber="429">Lucinid clade B</emphasis>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AEDAFBE5FDD582DD" pageId="8" pageNumber="429" type="discussion">
<paragraph id="8BCD36E8FFE90629AEDAFBE5FE1D816D" blockId="8.[142,758,999,1757]" pageId="8" pageNumber="429">
This large clade contains many of the lucinid genera analysed including 
<taxonomicName id="4C724D6BFFE90629AF20FBC6FE20803A" box="[372,452,1061,1082]" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AF20FBC6FE20803A" box="[372,452,1061,1082]" italics="true" pageId="8" pageNumber="429">Lucina</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE90629AF80FBC6FD8E803A" authorityName="Sacco" authorityYear="1901" box="[468,618,1061,1082]" class="Bivalvia" family="Lucinidae" genus="Cardiolucina" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AF80FBC6FD8E803A" box="[468,618,1061,1082]" italics="true" pageId="8" pageNumber="429">Cardiolucina</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE90629AC2FFBC6FD0B803A" authorityName="Iredale" authorityYear="1930" box="[635,751,1061,1082]" class="Bivalvia" family="Lucinidae" genus="Wallucina" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AC2FFBC6FD0B803A" box="[635,751,1061,1082]" italics="true" pageId="8" pageNumber="429">Wallucina</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE90629AEDAFBA7FF068059" baseAuthorityName="Southward" baseAuthorityYear="1986" box="[142,226,1092,1113]" class="Bivalvia" family="Lucinidae" genus="Loripes" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AEDAFBA7FF068059" box="[142,226,1092,1113]" italics="true" pageId="8" pageNumber="429">Loripes</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE90629AEA4FBA0FE848058" box="[240,352,1091,1112]" class="Bivalvia" family="Lucinidae" genus="Austriella" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AEA4FBA0FE848058" box="[240,352,1091,1112]" italics="true" pageId="8" pageNumber="429">Austriella</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE90629AF3AFBA0FE088058" baseAuthorityName="Gros, Frenkiel &amp; Felbeck" baseAuthorityYear="2000" box="[366,492,1091,1112]" class="Bivalvia" family="Lucinidae" genus="Divaricella" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AF3AFBA0FE088058" box="[366,492,1091,1112]" italics="true" pageId="8" pageNumber="429">Divaricella</emphasis>
</taxonomicName>
, 
<emphasis id="B906EAFAFFE90629AFAFFBA7FDA78059" box="[507,579,1092,1113]" italics="true" pageId="8" pageNumber="429">
<taxonomicName id="4C724D6BFFE90629AFAFFBA7FDA48059" authorityName="J.D.Taylor &amp; Glover" authorityYear="2000" box="[507,576,1092,1113]" class="Bivalvia" family="Lucinidae" genus="Rasta" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">Rasta</taxonomicName>
,
</emphasis>
and the hydrothermal vent species 
<taxonomicName id="4C724D6BFFE90629AFEBFB81FE1D8097" authority="(Glover et al., 2004) Although" authorityName="Although" baseAuthorityName="Glover" baseAuthorityYear="2004" class="Bivalvia" family="Lucinidae" genus="Bathyaustriella" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="thionipta">
<emphasis id="B906EAFAFFE90629AFEBFB81FD118077" box="[447,757,1122,1143]" italics="true" pageId="8" pageNumber="429">Bathyaustriella thionipta</emphasis>
(
<bibRefCitation id="EFE34B19FFE90629AEC1FB62FE9F8097" author="Glover EA &amp; Taylor JD &amp; Rowden AA" box="[149,379,1153,1175]" pageId="8" pageNumber="429" pagination="283 - 295" refId="ref9250" refString="Glover EA, Taylor JD, Rowden AA. 2004. Bathyaustriella thionipta, a new lucinid bivalve from a hydrothermal vent on the Kermadec Ridge, New Zealand and its relationship to shallow-water taxa (Bivalvia: Lucinidae). Journal of Molluscan Studies 70: 283 - 295." type="journal article" year="2004">
Glover 
<emphasis id="B906EAFAFFE90629AEA4FB62FECB8096" box="[240,303,1153,1174]" italics="true" pageId="8" pageNumber="429">et al.</emphasis>
, 2004
</bibRefCitation>
) Although
</taxonomicName>
there are groupings within this clade (e.g. 
<taxonomicName id="4C724D6BFFE90629AFF4FB43FE1080B5" baseAuthorityName="Southward" baseAuthorityYear="1986" box="[416,500,1184,1205]" class="Bivalvia" family="Lucinidae" genus="Loripes" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AFF4FB43FE1080B5" box="[416,500,1184,1205]" italics="true" pageId="8" pageNumber="429">Loripes</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE90629AC52FB7CFD9E80B4" authorityName="Iredale" authorityYear="1930" box="[518,634,1183,1204]" class="Bivalvia" family="Lucinidae" genus="Wallucina" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AC52FB7CFD9E80B4" box="[518,634,1183,1204]" italics="true" pageId="8" pageNumber="429">Wallucina</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE90629ACEAFB7CFF2A80D4" class="Bivalvia" family="Lucinidae" genus="Chavania" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629ACEAFB7CFF2A80D4" italics="true" pageId="8" pageNumber="429">Chavania</emphasis>
</taxonomicName>
; 
<bibRefCitation id="EFE34B19FFE90629AE8FFB5DFE2480D3" author="Williams ST &amp; Taylor JD &amp; Glover EA" box="[219,448,1214,1236]" pageId="8" pageNumber="429" pagination="187 - 202" refId="ref10661" refString="Williams ST, Taylor JD, Glover EA. 2004. Molecular phylogeny of the Lucinoidea (Bivalvia): non-monophyly and separate acquisition of bacterial chemosymbiosis. Journal of Molluscan Studies 70: 187 - 202." type="journal article" year="2004">
Williams 
<emphasis id="B906EAFAFFE90629AF1CFB5CFE9D80D3" box="[328,377,1214,1236]" italics="true" pageId="8" pageNumber="429">et al</emphasis>
. 2004
</bibRefCitation>
: figs 1, 4) they are less well supported (&gt; 90% posterior probabilities). 
<taxonomicName id="4C724D6BFFE90629ACD0FB3EFE1E8111" authority="(d'Orbigny, 1842)" baseAuthorityName="d'Orbigny" baseAuthorityYear="1842" class="Bivalvia" family="Lucinidae" genus="Divalinga" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="quadrisulcata">
<emphasis id="B906EAFAFFE90629ACD0FB3EFEC98110" italics="true" pageId="8" pageNumber="429">Divalinga quadrisulcata</emphasis>
(d’Orbigny, 1842)
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFE90629AC62FB18FECC8130" authority="(Smith, 1885)" baseAuthorityName="Smith" baseAuthorityYear="1885" class="Bivalvia" family="Lucinidae" genus="Divaricella" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="irpex">
<emphasis id="B906EAFAFFE90629AC62FB18FD128111" box="[566,758,1275,1297]" italics="true" pageId="8" pageNumber="429">Divaricella irpex</emphasis>
(Smith, 1885)
</taxonomicName>
fall within this clade and the separation by 
<bibRefCitation id="EFE34B19FFE90629AEE1FADAFE86814F" author="Chavan A" box="[181,354,1337,1359]" pageId="8" pageNumber="429" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan (1969)</bibRefCitation>
of the genera into the subfamily 
<taxonomicName id="4C724D6BFFE90629AEDAFAB4FECA816D" authorityName="Gilbert" authorityYear="1967" box="[142,302,1367,1389]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="subFamily" subFamily="Divaricellinae">Divaricellinae</taxonomicName>
is not supported.
</paragraph>
<paragraph id="8BCD36E8FFE90629AEF3FA95FDD582DD" blockId="8.[142,758,999,1757]" pageId="8" pageNumber="429">
The position of 
<taxonomicName id="4C724D6BFFE90629AF03FA95FD12818C" authority="(Gmelin, 1792)" baseAuthorityName="Gmelin" baseAuthorityYear="1792" box="[343,758,1398,1420]" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="pectinatus">
<emphasis id="B906EAFAFFE90629AF03FA95FDA1818C" box="[343,581,1398,1420]" italics="true" pageId="8" pageNumber="429">Phacoides pectinatus</emphasis>
(Gmelin, 1792)
</taxonomicName>
is unresolved; in the 18S rRNA tree it forms a poorly supported sister taxon to 
<taxonomicName id="4C724D6BFFE90629AFE4FA50FDC281C8" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[432,550,1459,1480]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AFE4FA50FDC281C8" box="[432,550,1459,1480]" italics="true" pageId="8" pageNumber="429">Anodontia</emphasis>
</taxonomicName>
, while in the combined 18S/28S rRNA tree it forms a sister to Lucinid clade B. The species has many small indels and base changes not shared with other lucinids. Additionally, it has distinctive mantle gills and extensive mantle fusion similar to 
<taxonomicName id="4C724D6BFFE90629AF06F9AEFE2C8262" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[338,456,1613,1634]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AF06F9AEFE2C8262" box="[338,456,1613,1634]" italics="true" pageId="8" pageNumber="429">Anodontia</emphasis>
</taxonomicName>
species (see below). There is probably only a single living species of 
<taxonomicName id="4C724D6BFFE90629ACD7F988FD118280" box="[643,757,1643,1664]" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629ACD7F988FD118280" box="[643,757,1643,1664]" italics="true" pageId="8" pageNumber="429">Phacoides</emphasis>
</taxonomicName>
and its relationships are obscure; 
<bibRefCitation id="EFE34B19FFE90629AC10F969FD1282A0" author="Chavan A" box="[580,758,1674,1696]" pageId="8" pageNumber="429" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan (1969)</bibRefCitation>
thought it related to 
<taxonomicName id="4C724D6BFFE90629AFF5F94AFDEB82BE" authority="Bretsky (1976)" authorityName="Dall" authorityYear="1901" box="[417,527,1705,1726]" class="Bivalvia" family="Lucinidae" genus="Lucinisca" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AFF5F94AFDEB82BE" box="[417,527,1705,1726]" italics="true" pageId="8" pageNumber="429">Lucinisca</emphasis>
</taxonomicName>
&amp; 
<bibRefCitation id="EFE34B19FFE90629AC10F94AFD1282BF" author="Bretsky SS" box="[580,758,1705,1727]" pageId="8" pageNumber="429" pagination="219 - 337" refId="ref8397" refString="Bretsky SS. 1976. Evolution and classification of the Lucinidae (Mollusca; Bivalvia). Palaeontographica Americana 8: 219 - 337." type="journal article" year="1976">Bretsky (1976)</bibRefCitation>
included it as a subgenus of 
<emphasis id="B906EAFAFFE90629AF8EF92BFDD582DD" box="[474,561,1736,1757]" italics="true" pageId="8" pageNumber="429">
<taxonomicName id="4C724D6BFFE90629AF8EF92BFDC982DD" box="[474,557,1736,1757]" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">Lucina</taxonomicName>
.
</emphasis>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AF7FF8F1FDBE8329" box="[299,602,1810,1834]" pageId="8" pageNumber="429" type="multiple">
<paragraph id="8BCD36E8FFE90629AF7FF8F1FDBE8329" blockId="8.[299,602,1810,1834]" box="[299,602,1810,1834]" pageId="8" pageNumber="429">ANATOMICAL CHARACTERS</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AEDAF8D8FAD58535" pageId="8" pageNumber="429" type="discussion">
<paragraph id="8BCD36E8FFE90629AEDAF8D8FAD58535" blockId="8.[142,758,1851,1903]" lastBlockId="8.[806,1421,195,309]" pageId="8" pageNumber="429">Reviewed in the context of molecular analyses, anatomical studies are revealing characters that may prove useful in phylogenetic analyses and also in tracking the evolutionary adaptations to the symbiosis. In the following section we briefly describe some results from major organ systems of lucinids.</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AD72FE98FC1D8591" box="[806,1017,379,401]" pageId="8" pageNumber="429" type="multiple">
<paragraph id="8BCD36E8FFE90629AD72FE98FC1D8591" blockId="8.[806,1423,379,1904]" box="[806,1017,379,401]" pageId="8" pageNumber="429">
<emphasis id="B906EAFAFFE90629AD72FE98FC1D8591" box="[806,1017,379,401]" italics="true" pageId="8" pageNumber="429">Ctenidial structure</emphasis>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AD72FE79FACB873F" pageId="8" pageNumber="429" type="discussion">
<paragraph id="8BCD36E8FFE90629AD72FE79FACB873F" blockId="8.[806,1423,379,1904]" pageId="8" pageNumber="429">
Because the ctenidia house the chemosymbiotic bacteria their structure has been investigated in much more detail than any other feature of lucinid anatomy. Detailed electron microscopic studies are available for a wide variety of genera including: 
<emphasis id="B906EAFAFFE90629AA94FDF6FAC4862A" box="[1216,1312,533,554]" italics="true" pageId="8" pageNumber="429">
<taxonomicName id="4C724D6BFFE90629AA94FDF6FAF4862A" box="[1216,1296,533,554]" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">Lucina</taxonomicName>
(
</emphasis>
as 
<taxonomicName id="4C724D6BFFE90629AB16FDF6FA61862A" box="[1346,1413,533,554]" class="Bivalvia" family="Lucinidae" genus="Linga" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AB16FDF6FA61862A" box="[1346,1413,533,554]" italics="true" pageId="8" pageNumber="429">Linga</emphasis>
</taxonomicName>
) (
<bibRefCitation id="EFE34B19FFE90629AD7AFDD0FB488649" author="Frenkiel L &amp; Gros O &amp; Moueza M" box="[814,1196,563,585]" pageId="8" pageNumber="429" pagination="511 - 524" refId="ref8984" refString="Frenkiel L, Gros O, Moueza M. 1996. Gill structure in Lucina pectinata (Bivalvia: Lucinidae) with reference to hemoglobin in bivalves with symbiotic sulphur-oxidising bacteria. Marine Biology 125: 511 - 524." type="journal article" year="1996">Gros, Frenkiel &amp; Mouëza, 1996</bibRefCitation>
); 
<taxonomicName id="4C724D6BFFE90629AA91FDD0FB8A8668" authority="(Gros, Liberge &amp; Felbeck, 2003)" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AA91FDD0FADF8648" box="[1221,1339,563,584]" italics="true" pageId="8" pageNumber="429">Anodontia</emphasis>
(
<bibRefCitation id="EFE34B19FFE90629AB05FDD0FB828668" author="Gros O &amp; Liberge M &amp; Felbeck H" pageId="8" pageNumber="429" pagination="57 - 66" refId="ref9413" refString="Gros O, Liberge M, Felbeck H. 2003. Interspecific infection of aposymbiotic juveniles of Codakia orbicularis by various tropical lucinid gill-endosymbionts. Marine Biology 142: 57 - 66." type="journal article" year="2003">Gros, Liberge &amp; Felbeck, 2003</bibRefCitation>
)
</taxonomicName>
; 
<taxonomicName id="4C724D6BFFE90629AAD3FDB1FB028667" authorityName="Scopoli" authorityYear="1777" box="[1159,1254,594,615]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AAD3FDB1FB028667" box="[1159,1254,594,615]" italics="true" pageId="8" pageNumber="429">Codakia</emphasis>
</taxonomicName>
(
<bibRefCitation id="EFE34B19FFE90629AB57FDB1FC238687" author="Frenkiel L &amp; Moueza M" pageId="8" pageNumber="429" pagination="51 - 61" refId="ref9024" refString="Frenkiel L, Moueza M. 1995. Gill ultrastructure and symbiotic bacteria in Codakia orbicularis (Bivalvia, Lucinidae). Zoomorphology 115: 51 - 61." type="journal article" year="1995">Frenkiel &amp; Mouëza, 1995</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE90629AD80FD92FAA68687" author="Gros O &amp; Frenkiel L &amp; Moueza M" box="[980,1346,625,647]" pageId="8" pageNumber="429" pagination="219 - 231" refId="ref9371" refString="Gros O, Frenkiel L, Moueza M. 1998. Gill filament differentiation and experimental colonization by symbiotic bacteria in aposymbiotic juveniles of Codakia orbicularis (Bivalvia: Lucinidae). Invertebrate Reproduction and Development 34: 219 - 231." type="journal article" year="1998">Gros, Frenkiel &amp; Mouëza, 1998</bibRefCitation>
), 
<emphasis id="B906EAFAFFE90629AB0CFD92FC9A86A5" italics="true" pageId="8" pageNumber="429">
<taxonomicName id="4C724D6BFFE90629AB0CFD92FC8E86A4" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">Phacoides</taxonomicName>
(
</emphasis>
as 
<taxonomicName id="4C724D6BFFE90629ADF0FD73FC1086A5" box="[932,1012,656,677]" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629ADF0FD73FC1086A5" box="[932,1012,656,677]" italics="true" pageId="8" pageNumber="429">Lucina</emphasis>
</taxonomicName>
) (
<bibRefCitation id="EFE34B19FFE90629AA44FD6CFA6E86A5" author="Frenkiel L &amp; Gros O &amp; Moueza M" box="[1040,1418,655,677]" pageId="8" pageNumber="429" pagination="511 - 524" refId="ref8984" refString="Frenkiel L, Gros O, Moueza M. 1996. Gill structure in Lucina pectinata (Bivalvia: Lucinidae) with reference to hemoglobin in bivalves with symbiotic sulphur-oxidising bacteria. Marine Biology 125: 511 - 524." type="journal article" year="1996">Frenkiel, Gros &amp; Mouëza, 1996</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE90629AD72FD4DFB7986C4" author="Liberge M &amp; Gros O &amp; Frenkiel L" box="[806,1181,686,708]" pageId="8" pageNumber="429" pagination="401 - 409" refId="ref9719" refString="Liberge M, Gros O, Frenkiel L. 2001. Lysosomes and sulfide-oxidising bodies in the bacteriocytes of Lucina pectinata, a cytochemical and microanalysis approach. Marine Biology 139: 401 - 409." type="journal article" year="2001">Liberge, Gros &amp; Frenkiel, 2001</bibRefCitation>
); 
<taxonomicName id="4C724D6BFFE90629AAE2FD4CFACC86C4" authorityName="Dall" authorityYear="1901" box="[1206,1320,687,708]" class="Bivalvia" family="Lucinidae" genus="Lucinoma" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AAE2FD4CFACC86C4" box="[1206,1320,687,708]" italics="true" pageId="8" pageNumber="429">Lucinoma</emphasis>
</taxonomicName>
(
<bibRefCitation id="EFE34B19FFE90629AB68FD4DFB4086E3" author="Dando PR &amp; Southward AJ &amp; Southward EC" pageId="8" pageNumber="429" pagination="227 - 247" refId="ref8772" refString="Dando PR, Southward AJ, Southward EC. 1986. Chemoautotrophic symbionts in the gills of the bivalve mollusc Lucinoma borealis and the sediment chemistry of its habitat. Proceedings of the Royal Society of London B 227: 227 - 247." type="journal article" year="1986">Dando, Southward &amp; Southward, 1986</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE90629AAECFD2EFCBB8701" author="Distel DL &amp; Felbeck H" pageId="8" pageNumber="429" pagination="79 - 86" refId="ref8879" refString="Distel DL, Felbeck H. 1987. Endosymbiosis in the lucinid clams Lucinoma aequizonata, Lucinoma annulata and Lucina floridana: a rexamination of the functional morphology of the gills as bacteria-bearing organs. Marine Biology 96: 79 - 86." type="journal article" year="1987">Distel &amp; Felbeck, 1987</bibRefCitation>
); 
<taxonomicName id="4C724D6BFFE90629AD21FD08FAE68701" authority="(Reid &amp; Brand, 1986)" baseAuthorityName="Reid &amp; Brand" baseAuthorityYear="1986" box="[885,1282,747,769]" class="Bivalvia" family="Lucinidae" genus="Parvilucina" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AD21FD08FC1E8700" box="[885,1018,747,768]" italics="true" pageId="8" pageNumber="429">Parvilucina</emphasis>
(
<bibRefCitation id="EFE34B19FFE90629AA5FFD08FB1D8701" author="Reid RGB &amp; Brand DG" box="[1035,1273,747,769]" pageId="8" pageNumber="429" pagination="3 - 24" refId="ref10117" refString="Reid RGB, Brand DG. 1986. Sulfide-oxidising symbiosis in lucinaceans: implications for bivalve evolution. Veliger 29: 3 - 24." type="journal article" year="1986">Reid &amp; Brand, 1986</bibRefCitation>
)
</taxonomicName>
; 
<taxonomicName id="4C724D6BFFE90629AB44FD08FB468720" authority="(Gros, Frenkiel &amp; Felbeck, 2000)" baseAuthorityName="Gros, Frenkiel &amp; Felbeck" baseAuthorityYear="2000" class="Bivalvia" family="Lucinidae" genus="Divaricella" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AB44FD08FA6A8700" box="[1296,1422,747,768]" italics="true" pageId="8" pageNumber="429">Divaricella</emphasis>
(
<bibRefCitation id="EFE34B19FFE90629AD7AFCE9FB7F8720" author="Gros O &amp; Frenkiel L &amp; Felbeck H" box="[814,1179,778,800]" pageId="8" pageNumber="429" pagination="293 - 317" refId="ref9301" refString="Gros O, Frenkiel L, Felbeck H. 2000. Sulfur-oxidising endosymbioisis in Divaricella quadrisulcata (Bivalvia: Lucinidae): morphological, ultrastructural and phylogenetic analysis. Symbiosis 29: 293 - 317." type="journal article" year="2000">Gros, Frenkiel &amp; Felbeck, 2000</bibRefCitation>
)
</taxonomicName>
; 
<taxonomicName id="4C724D6BFFE90629AAFBFCE9FC0F873F" authority="(Herry &amp; Le Pennec, 1987)" baseAuthorityName="Herry &amp; Le Pennec" baseAuthorityYear="1987" class="Bivalvia" family="Lucinidae" genus="Lucinella" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AAFBFCE9FAFE871F" box="[1199,1306,778,799]" italics="true" pageId="8" pageNumber="429">Lucinella</emphasis>
(
<bibRefCitation id="EFE34B19FFE90629AB78FCE9FC07873F" author="Herry A &amp; Le Pennec M" pageId="8" pageNumber="429" pagination="25 - 36" refId="ref9479" refString="Herry A, Le Pennec M. 1987. Endosymbiotic bacteria in the gills of the littoral bivalve molluscs Thyasira flexuosa (Thyasiridae) and Lucinella divaricata (Lucinidae). Symbiosis 4: 25 - 36." type="journal article" year="1987">Herry &amp; Le Pennec, 1987</bibRefCitation>
)
</taxonomicName>
; 
<taxonomicName id="4C724D6BFFE90629ADACFCCAFACF873F" authority="(Southward, 1986)" baseAuthorityName="Southward" baseAuthorityYear="1986" box="[1016,1323,809,831]" class="Bivalvia" family="Lucinidae" genus="Loripes" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629ADACFCCAFBA8873E" box="[1016,1100,809,830]" italics="true" pageId="8" pageNumber="429">Loripes</emphasis>
(
<bibRefCitation id="EFE34B19FFE90629AA08FCCAFAC7873F" author="Southward EC" box="[1116,1315,809,831]" pageId="8" pageNumber="429" pagination="889 - 914" refId="ref10261" refString="Southward EC. 1986. Gill symbionts in thyasirids and other bivalve molluscs. Journal of the Marine Biology Association of the United Kingdom 66: 889 - 914." type="journal article" year="1986">Southward, 1986</bibRefCitation>
)
</taxonomicName>
.
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE90629AD6BFCA4FC418370" pageId="8" pageNumber="429" type="description">
<paragraph id="8BCD36E8FFE90629AD6BFCA4FA6B80CD" blockId="8.[806,1423,379,1904]" pageId="8" pageNumber="429">
All lucinids examined have a similar gill filament structure with a ciliated zone of frontal, eulateral and lateral cilia similar to that of other heterodont bivalves. Inwards of this is a narrow intermediary zone of several large cells and then a broad lateral zone comprising bacteriocytes, intercalary cells and mucocytes (
<figureCitation id="13492A6DFFE90629ADFFFC1CFC0F8016" box="[939,1003,1023,1046]" captionStart="Figure 8" captionStartId="9.[162,240,1165,1184]" captionTargetBox="[386,1218,188,1132]" captionTargetId="figure-406@9.[386,1219,188,1132]" captionTargetPageId="9" captionText="Figure 8. TEM section through part of ctenidial filament of Anodontia ovum (Reeve, 1850), Lizard Island, Queensland, showing central blood space flanked by bacteriocytes and intercalary cells. Scale bar = 5 µm. Abbreviations: b, bacteria; ba, bacteriocyte; bs, blood space; eic, distal extension of intercalary cell; ic, intercalary cell; ly, lysosome; m, microvilli; n, nucleus." figureDoi="http://doi.org/10.5281/zenodo.4687505" httpUri="https://zenodo.org/record/4687505/files/figure.png" pageId="8" pageNumber="429">Fig. 8</figureCitation>
). The symbiotic bacteria are usually contained in single vacuoles within the bacteriocytes. Although there are small differences in ctenidial structure between the species studied, for example the relative lack of mucoctyes in 
<taxonomicName id="4C724D6BFFE90629AA3FFB99FAFD808F" authorityName="Link" authorityYear="1807" box="[1131,1305,1146,1167]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="alba">
<emphasis id="B906EAFAFFE90629AA3FFB99FAFD808F" box="[1131,1305,1146,1167]" italics="true" pageId="8" pageNumber="429">Anodontia alba</emphasis>
</taxonomicName>
compared with other lucinids (
<bibRefCitation id="EFE34B19FFE90629AA58FB7AFB2C80AF" author="Gros O &amp; Liberge M &amp; Felbeck H" box="[1036,1224,1177,1199]" pageId="8" pageNumber="429" pagination="57 - 66" refId="ref9413" refString="Gros O, Liberge M, Felbeck H. 2003. Interspecific infection of aposymbiotic juveniles of Codakia orbicularis by various tropical lucinid gill-endosymbionts. Marine Biology 142: 57 - 66." type="journal article" year="2003">
Gros 
<emphasis id="B906EAFAFFE90629AA1EFB7AFB9F80AE" box="[1098,1147,1177,1198]" italics="true" pageId="8" pageNumber="429">et al</emphasis>
., 2003
</bibRefCitation>
), no phylogenetic pattern has yet been established for these differences.
</paragraph>
<paragraph id="8BCD36E8FFE90629AD6BFB35FC418370" blockId="8.[806,1423,379,1904]" pageId="8" pageNumber="429">
A striking feature of 
<taxonomicName id="4C724D6BFFE90629AA78FB35FC81810B" authority="(Linnaeus, 1758)" baseAuthorityName="Linnaeus" baseAuthorityYear="1758" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="orbicularis">
<emphasis id="B906EAFAFFE90629AA78FB35FAE980EB" box="[1068,1293,1238,1259]" italics="true" pageId="8" pageNumber="429">Codakia orbicularis</emphasis>
(Linnaeus, 1758)
</taxonomicName>
is the granule cells that occupy a large proportion of the inner part of the lateral zone, with the bacteriocytes restricted to the outermost portions (
<bibRefCitation id="EFE34B19FFE90629AD79FAB2FBBB8167" author="Frenkiel L &amp; Moueza M" box="[813,1119,1361,1383]" pageId="8" pageNumber="429" pagination="51 - 61" refId="ref9024" refString="Frenkiel L, Moueza M. 1995. Gill ultrastructure and symbiotic bacteria in Codakia orbicularis (Bivalvia, Lucinidae). Zoomorphology 115: 51 - 61." type="journal article" year="1995">Frenkiel &amp; Mouëza, 1995</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE90629AA3BFAB2FAD08167" author="Gros O &amp; Liberge M &amp; Felbeck H" box="[1135,1332,1361,1383]" pageId="8" pageNumber="429" pagination="57 - 66" refId="ref9413" refString="Gros O, Liberge M, Felbeck H. 2003. Interspecific infection of aposymbiotic juveniles of Codakia orbicularis by various tropical lucinid gill-endosymbionts. Marine Biology 142: 57 - 66." type="journal article" year="2003">
Gros 
<emphasis id="B906EAFAFFE90629AAE4FAB2FB058166" box="[1200,1249,1361,1382]" italics="true" pageId="8" pageNumber="429">et al</emphasis>
., 2003
</bibRefCitation>
). These cells are packed with spherical granules of various sizes to about 
<quantity id="4C8A9B0DFFE90629AD91FA6DFC1A81A4" box="[965,1022,1422,1444]" metricMagnitude="-3" metricUnit="m" metricValue="5.0" pageId="8" pageNumber="429" unit="mm" value="5.0">5 µm</quantity>
in diameter (
<figureCitation id="13492A6DFFE90629AAC1FA6DFB3281A4" box="[1173,1238,1422,1444]" captionStart="Figure 9" captionStartId="10.[142,220,715,734]" captionTargetBox="[146,754,194,682]" captionTargetId="figure-740@10.[146,754,194,682]" captionTargetPageId="10" captionText="Figure 9. SEM section of ctenidial filament of Lucinisca nassula (Conrad, 1846) showing bacteriocytes and granule cells. Scale bar = 10 µm. Abbreviations b, bacteriocyte with rod-shaped bacteria. gr, granule cell and granules." figureDoi="http://doi.org/10.5281/zenodo.4687507" httpUri="https://zenodo.org/record/4687507/files/figure.png" pageId="8" pageNumber="429">Fig. 9</figureCitation>
). The functional significance of the granules is uncertain, they are cystine-rich and may represent a means of storage of sulphur compounds. Such granule cells are seen in 
<taxonomicName id="4C724D6BFFE90629AD72F9EAFC61821E" authorityName="Scopoli" authorityYear="1777" box="[806,901,1545,1566]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AD72F9EAFC61821E" box="[806,901,1545,1566]" italics="true" pageId="8" pageNumber="429">Codakia</emphasis>
</taxonomicName>
species, in 
<taxonomicName id="4C724D6BFFE90629AA58F9EAFA6A821F" authority="(Conrad, 1846)" baseAuthorityName="Conrad" baseAuthorityYear="1846" box="[1036,1422,1545,1567]" class="Bivalvia" family="Lucinidae" genus="Lucinisca" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="nassula">
<emphasis id="B906EAFAFFE90629AA58F9EAFB3F821E" box="[1036,1243,1545,1566]" italics="true" pageId="8" pageNumber="429">Lucinisca nassula</emphasis>
(Conrad, 1846)
</taxonomicName>
(
<figureCitation id="13492A6DFFE90629AD7AF9C4FC8B823E" box="[814,879,1575,1598]" captionStart="Figure 9" captionStartId="10.[142,220,715,734]" captionTargetBox="[146,754,194,682]" captionTargetId="figure-740@10.[146,754,194,682]" captionTargetPageId="10" captionText="Figure 9. SEM section of ctenidial filament of Lucinisca nassula (Conrad, 1846) showing bacteriocytes and granule cells. Scale bar = 10 µm. Abbreviations b, bacteriocyte with rod-shaped bacteria. gr, granule cell and granules." figureDoi="http://doi.org/10.5281/zenodo.4687507" httpUri="https://zenodo.org/record/4687507/files/figure.png" pageId="8" pageNumber="429">Fig. 9</figureCitation>
), 
<taxonomicName id="4C724D6BFFE90629ADDEF9CBFB37823E" authority="(Conrad, 1837)" baseAuthorityName="Conrad" baseAuthorityYear="1837" box="[906,1235,1575,1598]" class="Bivalvia" family="Lucinidae" genus="Ctena" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="bella">
<emphasis id="B906EAFAFFE90629ADDEF9CBFBF6823C" box="[906,1042,1575,1597]" italics="true" pageId="8" pageNumber="429">Ctena bella</emphasis>
(Conrad, 1837)
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE90629AAB2F9C4FC9F825C" authorityName="Zorina" authorityYear="1978" class="Bivalvia" family="Lucinidae" genus="Pillucina" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="species" species="vietnamica">
<emphasis id="B906EAFAFFE90629AAB2F9C4FC9F825C" italics="true" pageId="8" pageNumber="429">Pillucina vietnamica</emphasis>
</taxonomicName>
, and some 
<taxonomicName id="4C724D6BFFE90629AA5BF9A4FB65825C" authorityName="Dall" authorityYear="1901" box="[1039,1153,1607,1628]" class="Bivalvia" family="Lucinidae" genus="Lucinoma" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AA5BF9A4FB65825C" box="[1039,1153,1607,1628]" italics="true" pageId="8" pageNumber="429">Lucinoma</emphasis>
</taxonomicName>
species (Dando 
<emphasis id="B906EAFAFFE90629AB1BF9A4FA64825B" box="[1359,1408,1606,1628]" italics="true" pageId="8" pageNumber="429">et al</emphasis>
., 1986; J. D. Taylor &amp; E. A. Glover, pers. observ.) but are absent in other lucinids. The presence of granule cells in some lucinids and not others probably reflects physiological differences in sulphur metabolism between the taxa. Our molecular analysis shows that 
<taxonomicName id="4C724D6BFFE90629AB73F93CFA6282F4" authorityName="Scopoli" authorityYear="1777" box="[1319,1414,1759,1780]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AB73F93CFA6282F4" box="[1319,1414,1759,1780]" italics="true" pageId="8" pageNumber="429">Codakia</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFE90629AD72F91DFC8D8313" box="[806,873,1790,1811]" class="Bivalvia" family="Lucinidae" genus="Ctena" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629AD72F91DFC8D8313" box="[806,873,1790,1811]" italics="true" pageId="8" pageNumber="429">Ctena</emphasis>
</taxonomicName>
, and 
<taxonomicName id="4C724D6BFFE90629ADE5F91CFBC78314" authorityName="Dall" authorityYear="1901" box="[945,1059,1791,1812]" class="Bivalvia" family="Lucinidae" genus="Lucinoma" kingdom="Animalia" order="Lucinoida" pageId="8" pageNumber="429" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE90629ADE5F91CFBC78314" box="[945,1059,1791,1812]" italics="true" pageId="8" pageNumber="429">Lucinoma</emphasis>
</taxonomicName>
group together into the same clade suggesting that the presence of granule cells in this group of species may be phylogenetically significant.
</paragraph>
</subSubSection>
<caption id="DF0D6660FFE80628AEF6FB6EFF1D80F8" ID-DOI="http://doi.org/10.5281/zenodo.4687505" ID-Zenodo-Dep="4687505" httpUri="https://zenodo.org/record/4687505/files/figure.png" pageId="9" pageNumber="430" startId="9.[162,240,1165,1184]" targetBox="[386,1218,188,1132]" targetPageId="9">
<paragraph id="8BCD36E8FFE80628AEF6FB6EFF1D80F8" blockId="9.[162,1443,1165,1272]" pageId="9" pageNumber="430">
<emphasis id="B906EAFAFFE80628AEF6FB6EFEEE80A0" bold="true" box="[162,266,1165,1184]" pageId="9" pageNumber="430">Figure 8.</emphasis>
TEM section through part of ctenidial filament of 
<taxonomicName id="4C724D6BFFE80628AD7BFB6EFB9180A0" authority="(Reeve, 1850)" baseAuthorityName="Reeve" baseAuthorityYear="1850" box="[815,1141,1165,1184]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="species" species="ovum">
<emphasis id="B906EAFAFFE80628AD7BFB6EFC39809F" box="[815,989,1165,1184]" italics="true" pageId="9" pageNumber="430">Anodontia ovum</emphasis>
(Reeve, 1850)
</taxonomicName>
, Lizard Island, Queensland, showing central blood space flanked by bacteriocytes and intercalary cells. Scale bar = 5 µm. Abbreviations: b, bacteria; ba, bacteriocyte; bs, blood space; eic, distal extension of intercalary cell; ic, intercalary cell; ly, lysosome; m, microvilli; n, nucleus.
</paragraph>
</caption>
<subSubSection id="C3686563FFE80628AEF6FAD2FECC8146" box="[162,296,1329,1350]" pageId="9" pageNumber="430" type="multiple">
<paragraph id="8BCD36E8FFE80628AEF6FAD2FECC8146" blockId="9.[162,778,1329,1904]" box="[162,296,1329,1350]" pageId="9" pageNumber="430">
<emphasis id="B906EAFAFFE80628AEF6FAD2FECC8146" box="[162,296,1329,1350]" italics="true" pageId="9" pageNumber="430">Mantle gills</emphasis>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFE8062BAEF6FAB2FF3F8148" lastPageId="10" lastPageNumber="431" pageId="9" pageNumber="430" type="description">
<paragraph id="8BCD36E8FFE80628AEF6FAB2FC2E82B8" blockId="9.[162,778,1329,1904]" lastBlockId="9.[826,1442,1330,1904]" pageId="9" pageNumber="430">
In some lucinids the inner surface of the anterior mantle around the anterior adductor muscle is modified to form secondary respiratory organs called mantle gills (
<bibRefCitation id="EFE34B19FFE80628AEFEFA4FFED681C2" author="Allen JA" box="[170,306,1452,1474]" pageId="9" pageNumber="430" pagination="421 - 484" refId="ref7956" refString="Allen JA. 1958. On the basic form and adaptations to habitat in the Lucinacea (Eulamellibranchia). Philosophical Transactions of the Royal Society of London B 241: 421 - 484." type="journal article" year="1958">Allen, 1958</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE80628AF16FA4FFDA981C2" author="Taylor JD &amp; Glover EA" box="[322,589,1452,1474]" pageId="9" pageNumber="430" pagination="207 - 225" refId="ref10393" refString="Taylor JD, Glover EA. 2000. Functional anatomy, chemosymbiosis and evolution of the Lucinidae. In: Harper EM, Taylor JD, Crame JA, eds. The Evolutionary Biology of the Bivalvia. Geological Society of London Special Publication 177: 207 - 225." type="journal article" year="2000">Taylor &amp; Glover, 2000</bibRefCitation>
). Although it is likely that in most lucinids the anterior mantle epithelium acts as a respiratory surface (extensive blood space beneath the epithelium and large pallial blood vessel runs to the site), in some species the mantle is elaborated into complex folded structures. In 
<taxonomicName id="4C724D6BFFE80628ACFEF9A5FCED825B" authorityName="Scopoli" authorityYear="1777" box="[682,777,1606,1627]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE80628ACFEF9A5FCED825B" box="[682,777,1606,1627]" italics="true" pageId="9" pageNumber="430">Codakia</emphasis>
</taxonomicName>
species, in the space between the anterior adductor and the mantle edge and extending from the ventral tip of the muscle, the inner mantle is folded into elongate pleats (
<figureCitation id="13492A6DFFE80628AF6BF923FE4582D6" box="[319,417,1728,1750]" captionStart="Figure 10" captionStartId="11.[162,240,1495,1514]" captionTargetBox="[162,1442,193,1462]" captionTargetId="figure-228@11.[162,1443,193,1463]" captionTargetPageId="11" captionText="Figure 10. Mantle gills in lucinids. A, Codakia tigerina; B, Lucina pensylvanica; C, Phacoides pectinatus; D, Anodontia philippiana. Scale bars = 1 mm." figureDoi="http://doi.org/10.5281/zenodo.4687509" httpUri="https://zenodo.org/record/4687509/files/figure.png" pageId="9" pageNumber="430">Fig. 10A</figureCitation>
). 
<taxonomicName id="4C724D6BFFE80628AFE9F923FD5082D6" baseAuthorityName="Gmelin" baseAuthorityYear="1792" box="[445,692,1728,1750]" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="species" species="pectinatus">
<emphasis id="B906EAFAFFE80628AFE9F923FD5082D6" box="[445,692,1728,1750]" italics="true" pageId="9" pageNumber="430">Phacoides pectinatus</emphasis>
</taxonomicName>
has a series of discrete lamellate ‘knots’ (
<figureCitation id="13492A6DFFE80628AC0EF93CFD5E82F5" box="[602,698,1759,1781]" captionStart="Figure 10" captionStartId="11.[162,240,1495,1514]" captionTargetBox="[162,1442,193,1462]" captionTargetId="figure-228@11.[162,1443,193,1463]" captionTargetPageId="11" captionText="Figure 10. Mantle gills in lucinids. A, Codakia tigerina; B, Lucina pensylvanica; C, Phacoides pectinatus; D, Anodontia philippiana. Scale bars = 1 mm." figureDoi="http://doi.org/10.5281/zenodo.4687509" httpUri="https://zenodo.org/record/4687509/files/figure.png" pageId="9" pageNumber="430">Fig. 10C</figureCitation>
) lying along and extending ventrally beyond the gutter between the adductor muscle and the mantle margin (
<bibRefCitation id="EFE34B19FFE80628AEFEF8D8FE0A8351" author="Narchi W &amp; Farani Assis RC" box="[170,494,1851,1873]" pageId="9" pageNumber="430" pagination="79 - 110" refId="ref9935" refString="Narchi W, Farani Assis RC. 1980. Anatomia functional de Lucina pectinata (Gmelin, 1791) Lucinidae-Bivalvia. Boletim de Zoologia Universidade de Sao Paulo 5: 79 - 110." type="journal article" year="1980">Narchi &amp; Farani Assis, 1980</bibRefCitation>
). In 
<taxonomicName id="4C724D6BFFE80628AC74F8DFFE87836F" authority="(Linnaeus, 1758)" baseAuthorityName="Linnaeus" baseAuthorityYear="1758" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="species" species="pensylvanica">
<emphasis id="B906EAFAFFE80628AC74F8DFFCED8350" box="[544,777,1851,1873]" italics="true" pageId="9" pageNumber="430">Lucina pensylvanica</emphasis>
(Linnaeus, 1758)
</taxonomicName>
(and 
<taxonomicName id="4C724D6BFFE80628AFFCF8B9FD0F8370" authority="d'Orbigny, 1839" authorityName="d'Orbigny" authorityYear="1839" box="[424,747,1882,1904]" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="species" species="adansoni">
<emphasis id="B906EAFAFFE80628AFFCF8B9FDCA836F" box="[424,558,1882,1903]" italics="true" pageId="9" pageNumber="430">L. adansoni</emphasis>
d’Orbigny, 1839
</taxonomicName>
) a pectinate branched structure lies to either side of the pallial blood vessel (
<figureCitation id="13492A6DFFE80628AA73FAB3FB6D8166" box="[1063,1161,1360,1382]" captionStart="Figure 10" captionStartId="11.[162,240,1495,1514]" captionTargetBox="[162,1442,193,1462]" captionTargetId="figure-228@11.[162,1443,193,1463]" captionTargetPageId="11" captionText="Figure 10. Mantle gills in lucinids. A, Codakia tigerina; B, Lucina pensylvanica; C, Phacoides pectinatus; D, Anodontia philippiana. Scale bars = 1 mm." figureDoi="http://doi.org/10.5281/zenodo.4687509" httpUri="https://zenodo.org/record/4687509/files/figure.png" pageId="9" pageNumber="430">Fig. 10B</figureCitation>
). For all 
<taxonomicName id="4C724D6BFFE80628AAA0FAB3FA8E8165" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[1268,1386,1360,1381]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE80628AAA0FAB3FA8E8165" box="[1268,1386,1360,1381]" italics="true" pageId="9" pageNumber="430">Anodontia</emphasis>
</taxonomicName>
species examined except 
<taxonomicName id="4C724D6BFFE80628AA6CFA8CFB6C8184" authorityName="Link" authorityYear="1807" box="[1080,1160,1391,1412]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="species" species="alba">
<emphasis id="B906EAFAFFE80628AA6CFA8CFB6C8184" box="[1080,1160,1391,1412]" italics="true" pageId="9" pageNumber="430">A. alba</emphasis>
</taxonomicName>
, the anterior end of the mantle septum (itself a large fold of the inner mantle epithelium) bears digitiform structures (
<figureCitation id="13492A6DFFE80628AB56FA4FFA8181C2" box="[1282,1381,1452,1474]" captionStart="Figure 10" captionStartId="11.[162,240,1495,1514]" captionTargetBox="[162,1442,193,1462]" captionTargetId="figure-228@11.[162,1443,193,1463]" captionTargetPageId="11" captionText="Figure 10. Mantle gills in lucinids. A, Codakia tigerina; B, Lucina pensylvanica; C, Phacoides pectinatus; D, Anodontia philippiana. Scale bars = 1 mm." figureDoi="http://doi.org/10.5281/zenodo.4687509" httpUri="https://zenodo.org/record/4687509/files/figure.png" pageId="9" pageNumber="430">Fig. 10D</figureCitation>
) that result from labyrinthine folding of the septum. In 
<taxonomicName id="4C724D6BFFE80628AB3BFA28FB368200" authority="(Deshayes, 1843)" baseAuthorityName="Deshayes" baseAuthorityYear="1843" class="Bivalvia" family="Lucinidae" genus="Austriella" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="species" species="corrugata">
<emphasis id="B906EAFAFFE80628AB3BFA28FC1881FF" italics="true" pageId="9" pageNumber="430">Austriella corrugata</emphasis>
(Deshayes, 1843)
</taxonomicName>
, a large ridge of folded mantle, accommodating extensive blood space, extends posteriorly from around the ventral tip of the adductor muscle. Finally, the so-called ‘mantle palps’ near the anterior adductor of 
<taxonomicName id="4C724D6BFFE80628AACEF987FA888279" baseAuthorityName="Linnaeus" baseAuthorityYear="1758" box="[1178,1388,1636,1657]" class="Bivalvia" family="Lucinidae" genus="Fimbria" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="species" species="fimbriata">
<emphasis id="B906EAFAFFE80628AACEF987FA888279" box="[1178,1388,1636,1657]" italics="true" pageId="9" pageNumber="430">Fimbria fimbriata</emphasis>
</taxonomicName>
(see 
<bibRefCitation id="EFE34B19FFE80628AD6EF960FBD28298" author="Allen JA &amp; Turner JF" box="[826,1078,1667,1689]" pageId="9" pageNumber="430" pagination="147 - 154" refId="ref7991" refString="Allen JA, Turner JF. 1970. The morphology of Fimbria fimbriata (Linne) (Bivalvia: Lucinidae). Pacific Science 24: 147 - 154." type="journal article" year="1970">Allen &amp; Turner, 1970</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFE80628AA10F960FB048299" author="Morton B" box="[1092,1248,1667,1689]" pageId="9" pageNumber="430" pagination="389 - 420" refId="ref9865" refString="Morton B. 1979. The biology and functional morphology of the coral-sand bivalve Fimbria fimbriata (Linnaeus, 1758). Records of the Australian Museum 32: 389 - 420." type="journal article" year="1979">Morton, 1979</bibRefCitation>
) are most likely mantle gills.
</paragraph>
<paragraph id="8BCD36E8FFE8062BAD07F923FF218015" blockId="9.[826,1442,1330,1904]" lastBlockId="10.[142,758,900,1352]" lastPageId="10" lastPageNumber="431" pageId="9" pageNumber="430">
Plotting the distribution of the mantle gills on the molecular phylogeny shows that they occur in five different clades. In the 
<taxonomicName id="4C724D6BFFE80628AA70F91DFB7E8313" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[1060,1178,1790,1811]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE80628AA70F91DFB7E8313" box="[1060,1178,1790,1811]" italics="true" pageId="9" pageNumber="430">Anodontia</emphasis>
</taxonomicName>
clade all the examined species except 
<taxonomicName id="4C724D6BFFE80628ADB4F8FFFB6B8331" authorityName="Link" authorityYear="1807" box="[992,1167,1820,1841]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="species" species="alba">
<emphasis id="B906EAFAFFE80628ADB4F8FFFB6B8331" box="[992,1167,1820,1841]" italics="true" pageId="9" pageNumber="430">Anodontia alba</emphasis>
</taxonomicName>
possess the septum and digitform gills, in Lucinid clade A only 
<taxonomicName id="4C724D6BFFE80628AB5EF8D8FA8D8350" authorityName="Scopoli" authorityYear="1777" box="[1290,1385,1851,1872]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="9" pageNumber="430" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFE80628AB5EF8D8FA8D8350" box="[1290,1385,1851,1872]" italics="true" pageId="9" pageNumber="430">Codakia</emphasis>
</taxonomicName>
species have the mantle gills and in Lucinid clade B only species of 
<emphasis id="B906EAFAFFEB062BAF5AFC66FE68879A" box="[270,396,901,922]" italics="true" pageId="10" pageNumber="431">
<taxonomicName id="4C724D6BFFEB062BAF5AFC66FEBA879A" box="[270,350,901,922]" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="genus" sensu="stricto">Lucina</taxonomicName>
<taxonomicNameLabel id="A2355781FFEB062BAF3FFC66FE68879A" box="[363,396,901,922]" pageId="10" pageNumber="431" sensu="stricto">s.s.</taxonomicNameLabel>
</emphasis>
possess the pectinate mantle gills. Also in clade B 
<taxonomicName id="4C724D6BFFEB062BAFCAFC40FDEA87B8" box="[414,526,931,952]" class="Bivalvia" family="Lucinidae" genus="Austriella" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEB062BAFCAFC40FDEA87B8" box="[414,526,931,952]" italics="true" pageId="10" pageNumber="431">Austriella</emphasis>
</taxonomicName>
has the thickened ridge. In 
<taxonomicName id="4C724D6BFFEB062BAEA2FC21FE8C87D7" box="[246,360,962,983]" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEB062BAEA2FC21FE8C87D7" box="[246,360,962,983]" italics="true" pageId="10" pageNumber="431">Phacoides</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C724D6BFFEB062BAFF6FC21FE1B87D7" box="[418,511,962,983]" class="Bivalvia" family="Lucinidae" genus="Fimbria" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEB062BAFF6FC21FE1B87D7" box="[418,511,962,983]" italics="true" pageId="10" pageNumber="431">Fimbria</emphasis>
</taxonomicName>
there are only one or two living species in the clades and both have mantle gills.
</paragraph>
<caption id="DF0D6660FFEB062BAEDAFD28FD478736" ID-DOI="http://doi.org/10.5281/zenodo.4687507" ID-Zenodo-Dep="4687507" httpUri="https://zenodo.org/record/4687507/files/figure.png" pageId="10" pageNumber="431" startId="10.[142,220,715,734]" targetBox="[146,754,194,682]" targetPageId="10">
<paragraph id="8BCD36E8FFEB062BAEDAFD28FD478736" blockId="10.[142,758,715,822]" pageId="10" pageNumber="431">
<emphasis id="B906EAFAFFEB062BAEDAFD28FF1286DE" bold="true" box="[142,246,715,734]" pageId="10" pageNumber="431">Figure 9.</emphasis>
SEM section of ctenidial filament of 
<taxonomicName id="4C724D6BFFEB062BACC5FD28FE6686FB" authority="(Conrad, 1846)" baseAuthorityName="Conrad" baseAuthorityYear="1846" class="Bivalvia" family="Lucinidae" genus="Lucinisca" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="species" species="nassula">
<emphasis id="B906EAFAFFEB062BACC5FD28FF3B86FB" italics="true" pageId="10" pageNumber="431">Lucinisca nassula</emphasis>
(Conrad, 1846)
</taxonomicName>
showing bacteriocytes and granule cells. Scale bar = 10 µm. Abbreviations b, bacteriocyte with rod-shaped bacteria. gr, granule cell and granules.
</paragraph>
</caption>
<paragraph id="8BCD36E8FFEB062BAEF3FBFDFF3F8148" blockId="10.[142,758,900,1352]" pageId="10" pageNumber="431">
Although these structures are thought to have a similar respiratory function they are unlikely all to be homologous – the pectinate organ in 
<taxonomicName id="4C724D6BFFEB062BAC1FFBBFFF3D808F" baseAuthorityName="Linnaeus" baseAuthorityYear="1758" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="species" species="pensylvanica">
<emphasis id="B906EAFAFFEB062BAC1FFBBFFF3D808F" italics="true" pageId="10" pageNumber="431">Lucina pensylvanica</emphasis>
</taxonomicName>
is structurally different from the others and appears derived from branching of the pallial blood vessel. Folding of the inner mantle surface to increase the surface area for respiration is a fairly obvious adaptational pathway and the various structures may have evolved independently in the different lucinid clades.
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFEB062BAEDAFA6DFDD081A2" box="[142,564,1421,1443]" pageId="10" pageNumber="431" type="multiple">
<paragraph id="8BCD36E8FFEB062BAEDAFA6DFDD081A2" blockId="10.[142,758,1421,1904]" box="[142,564,1421,1443]" pageId="10" pageNumber="431">
<emphasis id="B906EAFAFFEB062BAEDAFA6DFDD081A2" box="[142,564,1421,1443]" italics="true" pageId="10" pageNumber="431">Posterior apertures and mantle fusion</emphasis>
</paragraph>
</subSubSection>
<subSubSection id="C3686563FFEB062BAEDAFA4FFC8781A4" pageId="10" pageNumber="431" type="description">
<paragraph id="8BCD36E8FFEB062BAEDAFA4FFC9A8517" blockId="10.[142,758,1421,1904]" lastBlockId="10.[806,1422,195,1444]" pageId="10" pageNumber="431">
<taxonomicName id="4C724D6BFFEB062BAEDAFA4FFF1B81C2" box="[142,255,1452,1474]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
usually possess two posterior mantle apertures situated in a homologous position to the inhalant and exhalant siphons of other heterodont bivalves. The exhalant aperture of lucinids has an extensible tube, formed from fusion of the inner mantle fold, that retracts into the suprabranchial chamber. Preliminary observations and evidence from published figures (
<bibRefCitation id="EFE34B19FFEB062BAEC1F960FED48299" author="Allen JA" box="[149,304,1667,1689]" pageId="10" pageNumber="431" pagination="421 - 484" refId="ref7956" refString="Allen JA. 1958. On the basic form and adaptations to habitat in the Lucinacea (Eulamellibranchia). Philosophical Transactions of the Royal Society of London B 241: 421 - 484." type="journal article" year="1958">Allen, 1958</bibRefCitation>
) indicated considerable variation amongst lucinid species both in the length of posterior mantle fusion ventral to the inhalant aperture and also in the number of mantle folds involved in the fusion. Additionally, in some species the inhalant and sometimes also exhalant apertures are ringed with mantle papillae. Moreover, the eversible exhalant tube varies in size and robustness. A survey of more taxa has revealed a possible phylogenetic signal in these characters, although more comprehensive sampling is needed.
</paragraph>
<paragraph id="8BCD36E8FFEB062BAD6BFEC3FC328701" blockId="10.[806,1422,195,1444]" pageId="10" pageNumber="431">
In all species of 
<taxonomicName id="4C724D6BFFEB062BADA3FEFCFB898534" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[1015,1133,287,308]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEB062BADA3FEFCFB898534" box="[1015,1133,287,308]" italics="true" pageId="10" pageNumber="431">Anodontia</emphasis>
</taxonomicName>
examined, mantle fusion below the inhalant aperture is long (
<figureCitation id="13492A6DFFEB062BAAB9FEDDFAA98554" box="[1261,1357,318,340]" captionStart="Figure 11" captionStartId="12.[142,220,1703,1722]" captionTargetBox="[229,1335,190,1670]" captionTargetId="figure-147@12.[229,1335,190,1670]" captionTargetPageId="12" captionText="Figure 11. Posterior apertures of a range of lucinid species. All SEMs of critical point dried specimens. A, Anodontia omissa (Iredale, 1930), Moreton Bay Queensland; B, Phacoides pectinatus (Gmelin, 1792), Brazil; C, Bathyaustriella thionipta (Glover et al., 2004), Kermadec Ridge, New Zealand; D, Ctena bella (Conrad, 1837), Lizard Island, Queensland; E, Pillucina vietnamica Zorina, 1978, Port Douglas, Queensland; F, Wallucina assimilis (Angas, 1867), Jervis Bay, New South Wales; G, Lucina adansoni d’Orbigny, 1839, Cape Verde Islands. H, Cardiolucina pisiformis (Thiele, 1930), Shark Bay, Western Australia; I, Myrtea spinifera (Montagu, 1803), Oban Scotland. Images adjusted to similar scale. Abbreviations: ex, exhalant aperture; in, inhalant aperture; p, papillae; vf, ventral mantle fusion." figureDoi="http://doi.org/10.5281/zenodo.4687511" httpUri="https://zenodo.org/record/4687511/files/figure.png" pageId="10" pageNumber="431">Fig. 11A</figureCitation>
) and involves the inner and most of the middle mantle folds so that the middle fold forms a narrow ridge down the centre of the fused zone, flanked to either side by the periostracal groove. Thus, most of the fused zone is periostracum covered. There are no papillae around the apertures. A similar long, fused zone, involving most of the middle mantle fold, also occurs in 
<taxonomicName id="4C724D6BFFEB062BAB0CFDF6FC0E8649" baseAuthorityName="Gmelin" baseAuthorityYear="1792" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="species" species="pectinatus">
<emphasis id="B906EAFAFFEB062BAB0CFDF6FC0E8649" italics="true" pageId="10" pageNumber="431">Phacoides pectinatus</emphasis>
</taxonomicName>
(
<figureCitation id="13492A6DFFEB062BADA8FDD0FBB9864A" box="[1020,1117,563,586]" captionStart="Figure 11" captionStartId="12.[142,220,1703,1722]" captionTargetBox="[229,1335,190,1670]" captionTargetId="figure-147@12.[229,1335,190,1670]" captionTargetPageId="12" captionText="Figure 11. Posterior apertures of a range of lucinid species. All SEMs of critical point dried specimens. A, Anodontia omissa (Iredale, 1930), Moreton Bay Queensland; B, Phacoides pectinatus (Gmelin, 1792), Brazil; C, Bathyaustriella thionipta (Glover et al., 2004), Kermadec Ridge, New Zealand; D, Ctena bella (Conrad, 1837), Lizard Island, Queensland; E, Pillucina vietnamica Zorina, 1978, Port Douglas, Queensland; F, Wallucina assimilis (Angas, 1867), Jervis Bay, New South Wales; G, Lucina adansoni d’Orbigny, 1839, Cape Verde Islands. H, Cardiolucina pisiformis (Thiele, 1930), Shark Bay, Western Australia; I, Myrtea spinifera (Montagu, 1803), Oban Scotland. Images adjusted to similar scale. Abbreviations: ex, exhalant aperture; in, inhalant aperture; p, papillae; vf, ventral mantle fusion." figureDoi="http://doi.org/10.5281/zenodo.4687511" httpUri="https://zenodo.org/record/4687511/files/figure.png" pageId="10" pageNumber="431">Fig. 11B</figureCitation>
). Some 
<taxonomicName id="4C724D6BFFEB062BAAE8FDD0FAD68648" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[1212,1330,563,584]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEB062BAAE8FDD0FAD68648" box="[1212,1330,563,584]" italics="true" pageId="10" pageNumber="431">Anodontia</emphasis>
</taxonomicName>
species and 
<taxonomicName id="4C724D6BFFEB062BAD0CFDB1FBA18668" baseAuthorityName="Gmelin" baseAuthorityYear="1792" box="[856,1093,594,616]" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="species" species="pectinatus">
<emphasis id="B906EAFAFFEB062BAD0CFDB1FBA18668" box="[856,1093,594,616]" italics="true" pageId="10" pageNumber="431">Phacoides pectinatus</emphasis>
</taxonomicName>
live deeply burrowed in dysaerobic habitats and the extensive mantle fusion with its periostracal covering is a possible adaptation to protect the mantle and regulate passage of interstitial water into the mantle cavity by reducing the size of the pedal gape.
</paragraph>
<paragraph id="8BCD36E8FFEB062BAD6BFCE9FC3887D8" blockId="10.[806,1422,195,1444]" pageId="10" pageNumber="431">
Lucinids of Clade A (
<taxonomicName id="4C724D6BFFEB062BAA7DFCE9FB6C871F" authorityName="Scopoli" authorityYear="1777" box="[1065,1160,778,799]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEB062BAA7DFCE9FB6C871F" box="[1065,1160,778,799]" italics="true" pageId="10" pageNumber="431">Codakia</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C724D6BFFEB062BAAC1FCE9FB3C871F" box="[1173,1240,778,799]" class="Bivalvia" family="Lucinidae" genus="Ctena" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEB062BAAC1FCE9FB3C871F" box="[1173,1240,778,799]" italics="true" pageId="10" pageNumber="431">Ctena</emphasis>
</taxonomicName>
, 
<emphasis id="B906EAFAFFEB062BAAB7FCE8FAB88720" box="[1251,1372,779,800]" italics="true" pageId="10" pageNumber="431">
<taxonomicName id="4C724D6BFFEB062BAAB7FCE8FABC8720" authorityName="Dall" authorityYear="1901" box="[1251,1368,779,800]" class="Bivalvia" family="Lucinidae" genus="Lucinoma" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="genus">Lucinoma</taxonomicName>
,
</emphasis>
and 
<taxonomicName id="4C724D6BFFEB062BAD72FCCAFBF3873E" authorityName="Zorina" authorityYear="1978" box="[806,1047,809,830]" class="Bivalvia" family="Lucinidae" genus="Pillucina" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="species" species="vietnamica">
<emphasis id="B906EAFAFFEB062BAD72FCCAFBF3873E" box="[806,1047,809,830]" italics="true" pageId="10" pageNumber="431">Pillucina vietnamica</emphasis>
</taxonomicName>
) have only a short, fused zone ventral to the inhalant aperture, with the fusion involving inner mantle folds and the inner part of the middle folds (
<figureCitation id="13492A6DFFEB062BAD86FC66FBB8879A" box="[978,1116,901,923]" captionStart="Figure 11" captionStartId="12.[142,220,1703,1722]" captionTargetBox="[229,1335,190,1670]" captionTargetId="figure-147@12.[229,1335,190,1670]" captionTargetPageId="12" captionText="Figure 11. Posterior apertures of a range of lucinid species. All SEMs of critical point dried specimens. A, Anodontia omissa (Iredale, 1930), Moreton Bay Queensland; B, Phacoides pectinatus (Gmelin, 1792), Brazil; C, Bathyaustriella thionipta (Glover et al., 2004), Kermadec Ridge, New Zealand; D, Ctena bella (Conrad, 1837), Lizard Island, Queensland; E, Pillucina vietnamica Zorina, 1978, Port Douglas, Queensland; F, Wallucina assimilis (Angas, 1867), Jervis Bay, New South Wales; G, Lucina adansoni d’Orbigny, 1839, Cape Verde Islands. H, Cardiolucina pisiformis (Thiele, 1930), Shark Bay, Western Australia; I, Myrtea spinifera (Montagu, 1803), Oban Scotland. Images adjusted to similar scale. Abbreviations: ex, exhalant aperture; in, inhalant aperture; p, papillae; vf, ventral mantle fusion." figureDoi="http://doi.org/10.5281/zenodo.4687511" httpUri="https://zenodo.org/record/4687511/files/figure.png" pageId="10" pageNumber="431">Fig. 11D, E</figureCitation>
). Moreover, the inhalant apertures are fringed by short papillae arising from the middle fold.
</paragraph>
<paragraph id="8BCD36E8FFEB062BAD6BFC02FC8781A4" blockId="10.[806,1422,195,1444]" pageId="10" pageNumber="431">
Species of the 
<taxonomicName id="4C724D6BFFEB062BADBFFC02FBDF87F6" box="[1003,1083,993,1014]" class="Bivalvia" family="Lucinidae" genus="Myrtea" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEB062BADBFFC02FBDF87F6" box="[1003,1083,993,1014]" italics="true" pageId="10" pageNumber="431">Myrtea</emphasis>
</taxonomicName>
clade (
<figureCitation id="13492A6DFFEB062BAAC6FC02FB0D87F7" box="[1170,1257,993,1015]" captionStart="Figure 11" captionStartId="12.[142,220,1703,1722]" captionTargetBox="[229,1335,190,1670]" captionTargetId="figure-147@12.[229,1335,190,1670]" captionTargetPageId="12" captionText="Figure 11. Posterior apertures of a range of lucinid species. All SEMs of critical point dried specimens. A, Anodontia omissa (Iredale, 1930), Moreton Bay Queensland; B, Phacoides pectinatus (Gmelin, 1792), Brazil; C, Bathyaustriella thionipta (Glover et al., 2004), Kermadec Ridge, New Zealand; D, Ctena bella (Conrad, 1837), Lizard Island, Queensland; E, Pillucina vietnamica Zorina, 1978, Port Douglas, Queensland; F, Wallucina assimilis (Angas, 1867), Jervis Bay, New South Wales; G, Lucina adansoni d’Orbigny, 1839, Cape Verde Islands. H, Cardiolucina pisiformis (Thiele, 1930), Shark Bay, Western Australia; I, Myrtea spinifera (Montagu, 1803), Oban Scotland. Images adjusted to similar scale. Abbreviations: ex, exhalant aperture; in, inhalant aperture; p, papillae; vf, ventral mantle fusion." figureDoi="http://doi.org/10.5281/zenodo.4687511" httpUri="https://zenodo.org/record/4687511/files/figure.png" pageId="10" pageNumber="431">Fig. 11I</figureCitation>
) have simple, narrow apertures without papillae and a very short length of mantle fusion. In species of Lucinid clade B (
<figureCitation id="13492A6DFFEB062BAD7AFBDEFC188052" box="[814,1020,1085,1107]" captionStart="Figure 11" captionStartId="12.[142,220,1703,1722]" captionTargetBox="[229,1335,190,1670]" captionTargetId="figure-147@12.[229,1335,190,1670]" captionTargetPageId="12" captionText="Figure 11. Posterior apertures of a range of lucinid species. All SEMs of critical point dried specimens. A, Anodontia omissa (Iredale, 1930), Moreton Bay Queensland; B, Phacoides pectinatus (Gmelin, 1792), Brazil; C, Bathyaustriella thionipta (Glover et al., 2004), Kermadec Ridge, New Zealand; D, Ctena bella (Conrad, 1837), Lizard Island, Queensland; E, Pillucina vietnamica Zorina, 1978, Port Douglas, Queensland; F, Wallucina assimilis (Angas, 1867), Jervis Bay, New South Wales; G, Lucina adansoni d’Orbigny, 1839, Cape Verde Islands. H, Cardiolucina pisiformis (Thiele, 1930), Shark Bay, Western Australia; I, Myrtea spinifera (Montagu, 1803), Oban Scotland. Images adjusted to similar scale. Abbreviations: ex, exhalant aperture; in, inhalant aperture; p, papillae; vf, ventral mantle fusion." figureDoi="http://doi.org/10.5281/zenodo.4687511" httpUri="https://zenodo.org/record/4687511/files/figure.png" pageId="10" pageNumber="431">Fig. 11C, F, G, H</figureCitation>
), there is much variation in the degree of fusion, and further analysis of the less wellsupported subclades within this large group is needed to establish the existence of any systematic pattern. In 
<taxonomicName id="4C724D6BFFEB062BAD72FB54FC1A80CC" baseAuthorityName="Linnaeus" baseAuthorityYear="1758" box="[806,1022,1207,1228]" class="Bivalvia" family="Lucinidae" genus="Fimbria" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="species" species="fimbriata">
<emphasis id="B906EAFAFFEB062BAD72FB54FC1A80CC" box="[806,1022,1207,1228]" italics="true" pageId="10" pageNumber="431">Fimbria fimbriata</emphasis>
</taxonomicName>
(
<figureCitation id="13492A6DFFEB062BAA42FB54FB8080CE" box="[1046,1124,1207,1230]" captionStart="Figure 12" captionStartId="13.[162,240,1133,1152]" captionTargetBox="[166,774,188,1100]" captionTargetId="figure-611@13.[166,775,188,1100]" captionTargetPageId="13" captionText="Figure 12. Posterior apertures of Fimbria fimbriata (Lizard Island, Queensland) showing double row of papillae, and short length of mantle fusion ventral to inhalant aperture. Abbreviations: ex, exhalant aperture; in, inhalant aperture; pg, pedal gape; vf, ventral fusion." figureDoi="http://doi.org/10.5281/zenodo.4687513" httpUri="https://zenodo.org/record/4687513/files/figure.png" pageId="10" pageNumber="431">Fig. 12</figureCitation>
) there is short zone of fusion ventral to the inhalant aperture, but the whole apertural area is fringed by two rows of mantle papillae; an outer row of short papillae and an inner row of longer finger-like structures. These papillae may be associated with the coral sand habitat of this species and function to keep the mantle and apertures clear of sand.
</paragraph>
</subSubSection>
<subSection id="E2FD2F03FFEB062BAD2FFA1BFADC8210" box="[891,1336,1528,1552]" pageId="10" pageNumber="431" type="multiple">
<subSubSection id="C3686563FFEB062BAD2FFA1BFADC8210" box="[891,1336,1528,1552]" pageId="10" pageNumber="431" type="multiple">
<paragraph id="8BCD36E8FFEB062BAD2FFA1BFADC8210" blockId="10.[891,1336,1528,1552]" box="[891,1336,1528,1552]" pageId="10" pageNumber="431">
<heading id="D0858184FFEB062BAD2FFA1BFADC8210" allCaps="true" box="[891,1336,1528,1552]" centered="true" fontSize="10" level="1" pageId="10" pageNumber="431" reason="1">
FOSSIL RECORD OF 
<taxonomicName id="4C724D6BFFEB062BAAC3FA1BFADC8210" box="[1175,1336,1528,1552]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="family">LUCINIDAE</taxonomicName>
</heading>
</paragraph>
</subSubSection>
</subSection>
<subSubSection id="C3686563FFEB062CAD72F9C4FBE68687" lastPageId="13" lastPageNumber="434" pageId="10" pageNumber="431" type="discussion">
<paragraph id="8BCD36E8FFEB062BAD72F9C4FAC68370" blockId="10.[806,1422,1575,1904]" pageId="10" pageNumber="431">
Fossils with many of the features of modern 
<taxonomicName id="4C724D6BFFEB062BAB4FF9C4FA68823D" box="[1307,1420,1575,1597]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
can be recognized through the Cenozoic and back into the Mesozoic (
<bibRefCitation id="EFE34B19FFEB062BAD9CF986FB8C827B" author="Chavan A" box="[968,1128,1637,1659]" pageId="10" pageNumber="431" pagination="518" refId="ref8578" refString="Chavan A. 1969. Superfamily Lucinacea Fleming, 1828. In: Moore RC, ed. Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Bivalvia., Vol. 2. Boulder, Colorado: Geological Society of America and University of Kansas, N 491 - N 518." type="book chapter" year="1969">Chavan, 1969</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFEB062BAA27F986FAF6827B" author="Bretsky SS" box="[1139,1298,1637,1659]" pageId="10" pageNumber="431" pagination="219 - 337" refId="ref8397" refString="Bretsky SS. 1976. Evolution and classification of the Lucinidae (Mollusca; Bivalvia). Palaeontographica Americana 8: 219 - 337." type="journal article" year="1976">Bretsky, 1976</bibRefCitation>
). However, the Palaeozoic record of 
<taxonomicName id="4C724D6BFFEB062BAA61F960FB428299" box="[1077,1190,1667,1689]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
is more problematic and extremely patchy. Narrowing of the concept of 
<taxonomicName id="4C724D6BFFEB062BAD72F922FC4082D7" authorityName="J.Fleming" authorityYear="1828" box="[806,932,1729,1751]" class="Bivalvia" family="Lucinoidea" kingdom="Animalia" order="Veneroida" pageId="10" pageNumber="435" phylum="Mollusca" rank="family">Lucinoidea</taxonomicName>
to exclude 
<taxonomicName id="4C724D6BFFEB062BAA60F922FB2682D7" box="[1076,1218,1729,1751]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="10" pageNumber="431" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
and 
<taxonomicName id="4C724D6BFFEB062BAB51F922FA6A82D7" box="[1285,1422,1729,1751]" class="Bivalvia" family="Thyasiridae" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="family">Thyasiridae</taxonomicName>
has meant that Palaeozoic bivalves suggested as having ‘lucinoid’ affinities all need reappraisal. Such a course is outside the scope of this paper, but in order to document the antiquity of the 
<taxonomicName id="4C724D6BFFEB062BAADCF8D8FB1D8351" box="[1160,1273,1851,1873]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="10" pageNumber="431" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
we review a few fossils with probable lucinid characters.
</paragraph>
<caption id="DF0D6660FFEA062AAEF6FA34FE178208" ID-DOI="http://doi.org/10.5281/zenodo.4687509" ID-Zenodo-Dep="4687509" httpUri="https://zenodo.org/record/4687509/files/figure.png" pageId="11" pageNumber="432" startId="11.[162,240,1495,1514]" targetBox="[162,1442,193,1462]" targetPageId="11">
<paragraph id="8BCD36E8FFEA062AAEF6FA34FE178208" blockId="11.[162,1442,1495,1544]" pageId="11" pageNumber="432">
<emphasis id="B906EAFAFFEA062AAEF6FA34FEF381EA" bold="true" box="[162,279,1495,1514]" pageId="11" pageNumber="432">Figure 10.</emphasis>
Mantle gills in lucinids. A, 
<taxonomicName id="4C724D6BFFEA062AAC13FA34FD1D81EA" baseAuthorityName="Linnaeus" baseAuthorityYear="1758" box="[583,761,1495,1514]" class="Bivalvia" family="Lucinidae" genus="Codakia" kingdom="Animalia" order="Lucinoida" pageId="11" pageNumber="432" phylum="Mollusca" rank="species" species="tigerina">
<emphasis id="B906EAFAFFEA062AAC13FA34FD1D81EA" box="[583,761,1495,1514]" italics="true" pageId="11" pageNumber="432">Codakia tigerina</emphasis>
</taxonomicName>
; B, 
<taxonomicName id="4C724D6BFFEA062AAD72FA3BFC1B81EA" baseAuthorityName="Linnaeus" baseAuthorityYear="1758" box="[806,1023,1495,1514]" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="11" pageNumber="432" phylum="Mollusca" rank="species" species="pensylvanica">
<emphasis id="B906EAFAFFEA062AAD72FA3BFC1B81EA" box="[806,1023,1495,1514]" italics="true" pageId="11" pageNumber="432">Lucina pensylvanica</emphasis>
</taxonomicName>
; C, 
<taxonomicName id="4C724D6BFFEA062AAA7FFA34FAE381EA" baseAuthorityName="Gmelin" baseAuthorityYear="1792" box="[1067,1287,1495,1514]" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="11" pageNumber="432" phylum="Mollusca" rank="species" species="pectinatus">
<emphasis id="B906EAFAFFEA062AAA7FFA34FAE381EA" box="[1067,1287,1495,1514]" italics="true" pageId="11" pageNumber="432">Phacoides pectinatus</emphasis>
</taxonomicName>
; D, 
<taxonomicName id="4C724D6BFFEA062AAB61FA34FEF98207" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="11" pageNumber="432" phylum="Mollusca" rank="species" species="philippiana">
<emphasis id="B906EAFAFFEA062AAB61FA34FEF98207" italics="true" pageId="11" pageNumber="432">Anodontia philippiana</emphasis>
</taxonomicName>
. Scale bars = 1 mm.
</paragraph>
</caption>
<paragraph id="8BCD36E8FFEA062AAEEFF9A5FEFD8370" blockId="11.[162,778,1606,1904]" pageId="11" pageNumber="432">
The earliest bivalve that can be confidently assigned to the 
<taxonomicName id="4C724D6BFFEA062AAEB8F986FEB9827B" box="[236,349,1637,1659]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="11" pageNumber="432" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
is 
<emphasis id="B906EAFAFFEA062AAF2BF986FE27827A" box="[383,451,1637,1658]" italics="true" pageId="11" pageNumber="432">Iliona</emphasis>
<taxonomicName id="4C724D6BFFEA062AAF9EF986FD29827B" authority="(Hisinger, 1837)" baseAuthorityName="Hisinger" baseAuthorityYear="1837" box="[458,717,1637,1659]" class="Bivalvia" family="Lucinidae" genus="Ilionia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="11" pageNumber="432" phylum="Mollusca" rank="species" species="prisca">
<emphasis id="B906EAFAFFEA062AAF9EF986FDEB827A" box="[458,527,1637,1658]" italics="true" pageId="11" pageNumber="432">prisca</emphasis>
(Hisinger, 1837)
</taxonomicName>
from the Silurian (Ludlovian) of 
<collectingCountry id="F3657678FFEA062AAF8FF960FDD08299" box="[475,564,1667,1689]" name="Sweden" pageId="11" pageNumber="432">Sweden</collectingCountry>
(
<figureCitation id="13492A6DFFEA062AAC17F960FD218299" box="[579,709,1667,1689]" captionStart="Figure 13" captionStartId="14.[142,220,868,887]" captionTargetBox="[302,1262,195,835]" captionTargetId="figure-142@14.[302,1263,195,835]" captionTargetPageId="14" captionText="Figure 13. A, B, internal moulds showing right sides of Ilionia prisca, Silurian, Gotland, Sweden. A, BMNH, Shell length (SL) = 70 mm; B, BMNH, SL = 55 mm. C, D, outside and inside of left valve of Eomiltha voorhoevi, Recent, Mozambique, ANSP 234103, SL = 70 mm." figureDoi="http://doi.org/10.5281/zenodo.4687515" httpUri="https://zenodo.org/record/4687515/files/figure.png" pageId="11" pageNumber="432">Fig. 13A, B</figureCitation>
). This is a large, elongate, anteriorly extended bivalve, having a large anterior adductor muscle scar ventrally detached from the pallial line. 
<taxonomicName id="4C724D6BFFEA062AAFAEF903FDA082F5" box="[506,580,1760,1781]" class="Bivalvia" family="Lucinidae" genus="Ilionia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="11" pageNumber="432" phylum="Mollusca" rank="species" species="situ">
<emphasis id="B906EAFAFFEA062AAFAEF903FDA082F5" box="[506,580,1760,1781]" italics="true" pageId="11" pageNumber="432">In situ</emphasis>
</taxonomicName>
fossils have a life position similar to living lucinids (
<bibRefCitation id="EFE34B19FFEA062AAC1CF91DFD1A8314" author="Liljedahl L" box="[584,766,1790,1812]" pageId="11" pageNumber="432" pagination="219 - 235" refId="ref9755" refString="Liljedahl L. 1991. Contrasting feeding strategies in bivalves from the Silurian of Gotland. Palaeontology 34: 219 - 235." type="journal article" year="1991">Liljedahl, 1991</bibRefCitation>
). The rare living species 
<taxonomicName id="4C724D6BFFEA062AAFFFF8FEFF058351" authority="(Deshayes, 1857)" baseAuthorityName="Deshayes" baseAuthorityYear="1857" class="Bivalvia" family="Lucinidae" genus="Eomiltha" kingdom="Animalia" order="Lucinoida" pageId="11" pageNumber="432" phylum="Mollusca" rank="species" species="voorhoevi">
<emphasis id="B906EAFAFFEA062AAFFFF8FEFD6C8332" box="[427,648,1821,1842]" italics="true" pageId="11" pageNumber="432">Eomiltha voorhoevi</emphasis>
(Deshayes, 1857)
</taxonomicName>
is similar in shape and musculature to 
<taxonomicName id="4C724D6BFFEA062AACFAF8DFFCED8351" baseAuthorityName="Hisinger" baseAuthorityYear="1837" box="[686,777,1852,1873]" class="Bivalvia" family="Lucinidae" genus="Ilionia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="11" pageNumber="432" phylum="Mollusca" rank="species" species="prisca">
<emphasis id="B906EAFAFFEA062AACFAF8DFFCED8351" box="[686,777,1852,1873]" italics="true" pageId="11" pageNumber="432">I. prisca</emphasis>
</taxonomicName>
(
<figureCitation id="13492A6DFFEA062AAEFEF8B9FEE88370" box="[170,268,1882,1904]" captionStart="Figure 13" captionStartId="14.[142,220,868,887]" captionTargetBox="[302,1262,195,835]" captionTargetId="figure-142@14.[302,1263,195,835]" captionTargetPageId="14" captionText="Figure 13. A, B, internal moulds showing right sides of Ilionia prisca, Silurian, Gotland, Sweden. A, BMNH, Shell length (SL) = 70 mm; B, BMNH, SL = 55 mm. C, D, outside and inside of left valve of Eomiltha voorhoevi, Recent, Mozambique, ANSP 234103, SL = 70 mm." figureDoi="http://doi.org/10.5281/zenodo.4687515" httpUri="https://zenodo.org/record/4687515/files/figure.png" pageId="11" pageNumber="432">Fig. 13C</figureCitation>
).
</paragraph>
<paragraph id="8BCD36E8FFEA062CAD07F9A5FDE881A4" blockId="11.[826,1442,1606,1904]" lastBlockId="13.[162,778,1361,1904]" lastPageId="13" lastPageNumber="434" pageId="11" pageNumber="432">
Another fossil with distinct lucinid characters is 
<taxonomicName id="4C724D6BFFEA062AAD6EF986FB06827B" authority="La Rocque, 1950" authorityName="La Rocque" authorityYear="1950" box="[826,1250,1637,1659]" class="Bivalvia" family="Lucinidae" genus="Phenacocyclas" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="11" pageNumber="432" phylum="Mollusca" rank="species" species="pohli">
<emphasis id="B906EAFAFFEA062AAD6EF986FBFA827A" box="[826,1054,1637,1658]" italics="true" pageId="11" pageNumber="432">Phenacocyclas pohli</emphasis>
<bibRefCitation id="EFE34B19FFEA062AAA72F986FB06827B" author="La Rocque A" box="[1062,1250,1637,1659]" pageId="11" pageNumber="432" pagination="271 - 366" refId="ref9634" refString="La Rocque A. 1950. Pre-Traverse Devonian pelecypods of Michigan. Contributions from the Museum of Paleontology University of Michigan 7: 271 - 366." type="journal article" year="1950">La Rocque, 1950</bibRefCitation>
</taxonomicName>
from the Middle Devonian of Michigan. This has an elongate anterior adductor muscle scar that is detached from the pallial line and on internal moulds there is a succession of plications within the area between the muscle scar and the pallial line that could be interpreted as impressions of mantle gills (
<bibRefCitation id="EFE34B19FFEA062AAA66F8FEFB118333" author="La Rocque A" box="[1074,1269,1821,1843]" pageId="11" pageNumber="432" pagination="271 - 366" refId="ref9634" refString="La Rocque A. 1950. Pre-Traverse Devonian pelecypods of Michigan. Contributions from the Museum of Paleontology University of Michigan 7: 271 - 366." type="journal article" year="1950">La Rocque, 1950</bibRefCitation>
: plates 13, 14). There is also a marked posterior sulcus immediately ventral to the posterior adductor scar in a position similar to that of many modern lucinids. The musculature of 
<taxonomicName id="4C724D6BFFEC062CAF5EFA8CFE498184" box="[266,429,1391,1412]" class="Bivalvia" family="Lucinidae" genus="Phenacocyclas" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="13" pageNumber="434" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEC062CAF5EFA8CFE498184" box="[266,429,1391,1412]" italics="true" pageId="13" pageNumber="434">Phenacocyclas</emphasis>
</taxonomicName>
is similar to 
<emphasis id="B906EAFAFFEC062CAC11FA8CFD388185" box="[581,732,1391,1413]" italics="true" pageId="13" pageNumber="434">
Iliona 
<taxonomicName id="4C724D6BFFEC062CACC4FA93FD3C8185" baseAuthorityName="Hisinger" baseAuthorityYear="1837" box="[656,728,1392,1413]" class="Bivalvia" family="Lucinidae" genus="Ilionia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="13" pageNumber="434" phylum="Mollusca" rank="species" species="prisca">prisca</taxonomicName>
,
</emphasis>
but the shell is much less elongate.
</paragraph>
<caption id="DF0D6660FFED062DAEDAF944FC29836A" ID-DOI="http://doi.org/10.5281/zenodo.4687511" ID-Zenodo-Dep="4687511" httpUri="https://zenodo.org/record/4687511/files/figure.png" pageId="12" pageNumber="433" startId="12.[142,220,1703,1722]" targetBox="[229,1335,190,1670]" targetPageId="12">
<paragraph id="8BCD36E8FFED062DAEDAF944FC29836A" blockId="12.[142,1422,1703,1898]" pageId="12" pageNumber="433">
<emphasis id="B906EAFAFFED062DAEDAF944FEE782BA" bold="true" box="[142,259,1703,1722]" pageId="12" pageNumber="433">Figure 11.</emphasis>
Posterior apertures of a range of lucinid species. All SEMs of critical point dried specimens. A, 
<taxonomicName id="4C724D6BFFED062DAB75F944FE9182D7" authority="(Iredale, 1930)" baseAuthorityName="Iredale" baseAuthorityYear="1930" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="12" pageNumber="433" phylum="Mollusca" rank="species" species="omissa">
<emphasis id="B906EAFAFFED062DAB75F944FF3282D7" italics="true" pageId="12" pageNumber="433">Anodontia omissa</emphasis>
(Iredale, 1930)
</taxonomicName>
, Moreton Bay Queensland; B, 
<taxonomicName id="4C724D6BFFED062DACE1F927FBD782D7" authority="(Gmelin, 1792)" baseAuthorityName="Gmelin" baseAuthorityYear="1792" box="[693,1075,1732,1751]" class="Bivalvia" family="Lucinidae" genus="Phacoides" kingdom="Animalia" order="Lucinoida" pageId="12" pageNumber="433" phylum="Mollusca" rank="species" species="pectinatus">
<emphasis id="B906EAFAFFED062DACE1F927FC6B82D7" box="[693,911,1732,1751]" italics="true" pageId="12" pageNumber="433">Phacoides pectinatus</emphasis>
(Gmelin, 1792)
</taxonomicName>
, Brazil; C, 
<taxonomicName id="4C724D6BFFED062DAAF2F927FE6982F5" authority="(Glover et al., 2004)" baseAuthorityName="Glover" baseAuthorityYear="2004" class="Bivalvia" family="Lucinidae" genus="Bathyaustriella" kingdom="Animalia" order="Lucinoida" pageId="12" pageNumber="433" phylum="Mollusca" rank="species" species="thionipta">
<emphasis id="B906EAFAFFED062DAAF2F927FF5C82F4" italics="true" pageId="12" pageNumber="433">Bathyaustriella thionipta</emphasis>
(
<bibRefCitation id="EFE34B19FFED062DAE91F901FE6282F5" author="Glover EA &amp; Taylor JD &amp; Rowden AA" box="[197,390,1762,1781]" pageId="12" pageNumber="433" pagination="283 - 295" refId="ref9250" refString="Glover EA, Taylor JD, Rowden AA. 2004. Bathyaustriella thionipta, a new lucinid bivalve from a hydrothermal vent on the Kermadec Ridge, New Zealand and its relationship to shallow-water taxa (Bivalvia: Lucinidae). Journal of Molluscan Studies 70: 283 - 295." type="journal article" year="2004">
Glover 
<emphasis id="B906EAFAFFED062DAF46F901FEDB82F5" box="[274,319,1762,1781]" italics="true" pageId="12" pageNumber="433">et al</emphasis>
., 2004
</bibRefCitation>
)
</taxonomicName>
, Kermadec Ridge, New Zealand; D, 
<taxonomicName id="4C724D6BFFED062DAD50F901FBFA82F5" authority="(Conrad, 1837)" baseAuthorityName="Conrad" baseAuthorityYear="1837" box="[772,1054,1762,1781]" class="Bivalvia" family="Lucinidae" genus="Ctena" kingdom="Animalia" order="Lucinoida" pageId="12" pageNumber="433" phylum="Mollusca" rank="species" species="bella">
<emphasis id="B906EAFAFFED062DAD50F901FC9F82F5" box="[772,891,1762,1781]" italics="true" pageId="12" pageNumber="433">Ctena bella</emphasis>
(Conrad, 1837)
</taxonomicName>
, Lizard Island, Queensland; E, 
<taxonomicName id="4C724D6BFFED062DAB3CF901FE3F8312" authority="Zorina, 1978" authorityName="Zorina" authorityYear="1978" class="Bivalvia" family="Lucinidae" genus="Pillucina" kingdom="Animalia" order="Lucinoida" pageId="12" pageNumber="433" phylum="Mollusca" rank="species" species="vietnamica">
<emphasis id="B906EAFAFFED062DAB3CF901FEAF8312" italics="true" pageId="12" pageNumber="433">Pillucina vietnamica</emphasis>
Zorina, 1978
</taxonomicName>
, Port Douglas, Queensland; F, 
<taxonomicName id="4C724D6BFFED062DAD70F91CFB6B8312" authority="(Angas, 1867)" baseAuthorityName="Angas" baseAuthorityYear="1867" box="[804,1167,1791,1810]" class="Bivalvia" family="Lucinidae" genus="Wallucina" kingdom="Animalia" order="Lucinoida" pageId="12" pageNumber="433" phylum="Mollusca" rank="species" species="assimilis">
<emphasis id="B906EAFAFFED062DAD70F91CFC118312" box="[804,1013,1791,1810]" italics="true" pageId="12" pageNumber="433">Wallucina assimilis</emphasis>
(Angas, 1867)
</taxonomicName>
, Jervis Bay, New South Wales; G, 
<taxonomicName id="4C724D6BFFED062DAEAFF8FEFD84832F" authority="d'Orbigny, 1839" authorityName="d'Orbigny" authorityYear="1839" box="[251,608,1820,1839]" class="Bivalvia" family="Lucinidae" genus="Lucina" kingdom="Animalia" order="Lucinoida" pageId="12" pageNumber="433" phylum="Mollusca" rank="species" species="adansoni">
<emphasis id="B906EAFAFFED062DAEAFF8FEFE4A832F" box="[251,430,1820,1839]" italics="true" pageId="12" pageNumber="433">Lucina adansoni</emphasis>
d’Orbigny, 1839
</taxonomicName>
, Cape Verde Islands. H, 
<taxonomicName id="4C724D6BFFED062DAD24F8FFFAEE832F" authority="(Thiele, 1930)" baseAuthorityName="Thiele" baseAuthorityYear="1930" box="[880,1290,1820,1839]" class="Bivalvia" family="Lucinidae" genus="Cardiolucina" kingdom="Animalia" order="Lucinoida" pageId="12" pageNumber="433" phylum="Mollusca" rank="species" species="pisiformis">
<emphasis id="B906EAFAFFED062DAD24F8FFFB88832F" box="[880,1132,1820,1839]" italics="true" pageId="12" pageNumber="433">Cardiolucina pisiformis</emphasis>
(Thiele, 1930)
</taxonomicName>
, Shark Bay, Western Australia; I, 
<taxonomicName id="4C724D6BFFED062DAF38F8D9FD2E834D" authority="(Montagu, 1803)" baseAuthorityName="Montagu" baseAuthorityYear="1803" box="[364,714,1850,1869]" class="Bivalvia" family="Lucinidae" genus="Myrtea" kingdom="Animalia" order="Lucinoida" pageId="12" pageNumber="433" phylum="Mollusca" rank="species" species="spinifera">
<emphasis id="B906EAFAFFED062DAF38F8D9FDFD834D" box="[364,537,1850,1869]" italics="true" pageId="12" pageNumber="433">Myrtea spinifera</emphasis>
(Montagu, 1803)
</taxonomicName>
, Oban Scotland. Images adjusted to similar scale. Abbreviations: ex, exhalant aperture; in, inhalant aperture; p, papillae; vf, ventral mantle fusion.
</paragraph>
</caption>
<subSection id="E2FD2F03FFEC062CADE5FD5FFB9A81E1" pageId="13" pageNumber="434" type="multiple">
<paragraph id="8BCD36E8FFEC062CADE5FD5FFAC886D4" blockId="13.[945,1324,700,724]" box="[945,1324,700,724]" pageId="13" pageNumber="434">
<heading id="D0858184FFEC062CADE5FD5FFAC886D4" allCaps="true" box="[945,1324,700,724]" centered="true" fontSize="10" level="1" pageId="13" pageNumber="434" reason="1">AGE OF CHEMOSYMBIOSIS</heading>
</paragraph>
<paragraph id="8BCD36E8FFEC062CAD6EFD08FB0387F7" blockId="13.[826,1442,747,1505]" pageId="13" pageNumber="434">
<bibRefCitation id="EFE34B19FFEC062CAD6EFD08FBE28701" author="Gros O &amp; Liberge M &amp; Felbeck H" box="[826,1030,747,769]" pageId="13" pageNumber="434" pagination="57 - 66" refId="ref9413" refString="Gros O, Liberge M, Felbeck H. 2003. Interspecific infection of aposymbiotic juveniles of Codakia orbicularis by various tropical lucinid gill-endosymbionts. Marine Biology 142: 57 - 66." type="journal article" year="2003">
Gros 
<emphasis id="B906EAFAFFEC062CAD28FD0FFC488700" box="[892,940,747,769]" italics="true" pageId="13" pageNumber="434">et al</emphasis>
. (2003)
</bibRefCitation>
demonstrated that the ctenidia of five species of lucinids from seagrass beds in the west Atlantic are colonized by the same sulphide-oxidizing bacterium, shown experimentally to be acquired from the sediment. These observations led the authors to suggest that the chemautotrophic symbiosis in 
<taxonomicName id="4C724D6BFFEC062CAD6EFC40FC4F87B9" box="[826,939,931,953]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="13" pageNumber="434" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
is relatively recent in comparison to other bivalve families (such as 
<taxonomicName id="4C724D6BFFEC062CAA24FC21FB1087D8" box="[1136,1268,962,984]" class="Bivalvia" family="Solemyidae" kingdom="Animalia" order="Solemyoida" pageId="13" pageNumber="434" phylum="Mollusca" rank="family">Solemyidae</taxonomicName>
) in which the symbionts are vertically transmitted.
</paragraph>
<paragraph id="8BCD36E8FFEC062CAD07FC1CFB9A81E1" blockId="13.[826,1442,747,1505]" pageId="13" pageNumber="434">
Previously, we have argued (
<bibRefCitation id="EFE34B19FFEC062CAAC8FC1CFA7F8015" author="Taylor JD &amp; Glover EA" box="[1180,1435,1023,1045]" pageId="13" pageNumber="434" pagination="207 - 225" refId="ref10393" refString="Taylor JD, Glover EA. 2000. Functional anatomy, chemosymbiosis and evolution of the Lucinidae. In: Harper EM, Taylor JD, Crame JA, eds. The Evolutionary Biology of the Bivalvia. Geological Society of London Special Publication 177: 207 - 225." type="journal article" year="2000">Taylor &amp; Glover, 2000</bibRefCitation>
) that the symbiosis in 
<taxonomicName id="4C724D6BFFEC062CAA67FBFDFB408034" box="[1075,1188,1054,1076]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="13" pageNumber="434" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
dates back to at least the Silurian. The evidence for this was based upon similarity of morphological characters between Recent and fossil lucinids, including the position and shape of the anterior adductor muscle, and the impression on the shell interior of the pallial blood vessel – both characters thought to be associated with the endosymbiosis. The Silurian 
<emphasis id="B906EAFAFFEC062CAA4EFB16FB4D810A" box="[1050,1193,1269,1290]" italics="true" pageId="13" pageNumber="434">
Iliona 
<taxonomicName id="4C724D6BFFEC062CAA30FB16FB4D810A" baseAuthorityName="Hisinger" baseAuthorityYear="1837" box="[1124,1193,1269,1290]" class="Bivalvia" family="Lucinidae" genus="Ilionia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="13" pageNumber="434" phylum="Mollusca" rank="species" species="prisca">prisca</taxonomicName>
</emphasis>
also had a similar life position to that of most Recent lucinids, orientated umbones upward in the sediment (
<bibRefCitation id="EFE34B19FFEC062CAAB5FAD1FA728148" author="Liljedahl L" box="[1249,1430,1330,1352]" pageId="13" pageNumber="434" pagination="219 - 235" refId="ref9755" refString="Liljedahl L. 1991. Contrasting feeding strategies in bivalves from the Silurian of Gotland. Palaeontology 34: 219 - 235." type="journal article" year="1991">Liljedahl, 1991</bibRefCitation>
). Additionally, the association of lucinids with cold seep sites and dysaerobic environments, dating back at least to the Jurassic (
<bibRefCitation id="EFE34B19FFEC062CAA17FA6DFAD681A3" author="Gaillard C &amp; Rios M &amp; Rolin Y &amp; Roux M" box="[1091,1330,1422,1444]" pageId="13" pageNumber="434" pagination="451 - 465" refId="ref9053" refString="Gaillard C, Rios M, Rolin Y, Roux M. 1992. Fossil chemosynthetic communities related to vents and seeps in sedimentary basins: the pseudobioherms of southeastern France compared to other world examples. Palaios 7: 451 - 465." type="journal article" year="1992">
Gaillard 
<emphasis id="B906EAFAFFEC062CAAFBFA6CFB0481A3" box="[1199,1248,1422,1444]" italics="true" pageId="13" pageNumber="434">et al</emphasis>
., 1992
</bibRefCitation>
; 
<bibRefCitation id="EFE34B19FFEC062CAB16FA6DFBEA81C3" author="Little CTS &amp; Vrijenhoek RC" pageId="13" pageNumber="434" pagination="582 - 588" refId="ref9778" refString="Little CTS, Vrijenhoek RC. 2003. Are hydrothermal vent animals living fossils? Trends in Ecology and Evolution 18: 582 - 588." type="journal article" year="2003">Little &amp; Vrijenhoek, 2003</bibRefCitation>
), is further suggestive of the chemoautotrophic life habit.
</paragraph>
</subSection>
<caption id="DF0D6660FFEC062CAEF6FB8EFD8E80F5" ID-DOI="http://doi.org/10.5281/zenodo.4687513" ID-Zenodo-Dep="4687513" httpUri="https://zenodo.org/record/4687513/files/figure.png" pageId="13" pageNumber="434" startId="13.[162,240,1133,1152]" targetBox="[166,774,188,1100]" targetPageId="13">
<paragraph id="8BCD36E8FFEC062CAEF6FB8EFD8E80F5" blockId="13.[162,778,1133,1270]" pageId="13" pageNumber="434">
<emphasis id="B906EAFAFFEC062CAEF6FB8EFEF38080" bold="true" box="[162,279,1133,1152]" pageId="13" pageNumber="434">Figure 12.</emphasis>
Posterior apertures of 
<taxonomicName id="4C724D6BFFEC062CAC46FB8EFD358080" baseAuthorityName="Linnaeus" baseAuthorityYear="1758" box="[530,721,1133,1152]" class="Bivalvia" family="Lucinidae" genus="Fimbria" kingdom="Animalia" order="Lucinoida" pageId="13" pageNumber="434" phylum="Mollusca" rank="species" species="fimbriata">
<emphasis id="B906EAFAFFEC062CAC46FB8EFD358080" box="[530,721,1133,1152]" italics="true" pageId="13" pageNumber="434">Fimbria fimbriata</emphasis>
</taxonomicName>
(Lizard Island, Queensland) showing double row of papillae, and short length of mantle fusion ventral to inhalant aperture. Abbreviations: ex, exhalant aperture; in, inhalant aperture; pg, pedal gape; vf, ventral fusion.
</paragraph>
</caption>
<paragraph id="8BCD36E8FFEC062CAEEFFA4EFBB385CE" blockId="13.[162,778,1361,1904]" lastBlockId="13.[826,1443,195,647]" pageId="13" pageNumber="434">
Some members of the family 
<taxonomicName id="4C724D6BFFEC062CAC46FA4EFD4181C3" authorityName="P.A.Johnston" authorityYear="1993" box="[530,677,1453,1475]" class="Bivalvia" family="Paracyclidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="13" pageNumber="434" phylum="Mollusca" rank="family">Paracyclidae</taxonomicName>
, such as those illustrated as 
<taxonomicName id="4C724D6BFFEC062CAFF0FA28FF068200" authority="(Goldfuss, 1840)" baseAuthorityName="Goldfuss" baseAuthorityYear="1840" class="Bivalvia" family="Mactromyidae" genus="Paracyclas" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="13" pageNumber="434" phylum="Mollusca" rank="species" species="proavia">
<emphasis id="B906EAFAFFEC062CAFF0FA28FD6281E1" box="[420,646,1483,1505]" italics="true" pageId="13" pageNumber="434">Paracyclas proavia</emphasis>
(Goldfuss, 1840)
</taxonomicName>
from the Devonian of 
<collectingCountry id="F3657678FFEC062CAC41FA09FD658200" box="[533,641,1514,1536]" name="Australia" pageId="13" pageNumber="434">Australia</collectingCountry>
(
<bibRefCitation id="EFE34B19FFEC062CACCEFA09FF3F821E" author="Johnston PA" pageId="13" pageNumber="434" pagination="1 - 134" refId="ref9609" refString="Johnston PA. 1993. Lower Devonian Pelecypoda from southeastern Australia. Memoirs of the Association of Australasian Palaeontologists 14: 1 - 134." type="journal article" year="1993">Johnston, 1993</bibRefCitation>
: figs 81A, 82A–D), are strikingly similar in shell morphology to modern 
<emphasis id="B906EAFAFFEC062CAC45F9C4FD6B823C" box="[529,655,1575,1596]" italics="true" pageId="13" pageNumber="434">
<taxonomicName id="4C724D6BFFEC062CAC45F9C4FD6F823C" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[529,651,1575,1596]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="13" pageNumber="434" phylum="Mollusca" rank="genus">Anodontia</taxonomicName>
.
</emphasis>
However, although they have an elongate anterior adductor muscle this is not detached from the pallial line and this led 
<bibRefCitation id="EFE34B19FFEC062CAF50F960FE13829A" author="Johnston PA" box="[260,503,1667,1690]" pageId="13" pageNumber="434" pagination="1 - 134" refId="ref9609" refString="Johnston PA. 1993. Lower Devonian Pelecypoda from southeastern Australia. Memoirs of the Association of Australasian Palaeontologists 14: 1 - 134." type="journal article" year="1993">Johnston (1993: 114)</bibRefCitation>
to suggest a similarity with 
<taxonomicName id="4C724D6BFFEC062CAEB6F941FE9482B8" box="[226,368,1698,1720]" class="Bivalvia" family="Ungulinidae" kingdom="Animalia" order="Veneroida" pageId="13" pageNumber="434" phylum="Mollusca" rank="family">Ungulinidae</taxonomicName>
rather than 
<taxonomicName id="4C724D6BFFEC062CAC47F941FD6C82B8" box="[531,648,1698,1720]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="13" pageNumber="434" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
. Nevertheless, other specimens of 
<taxonomicName id="4C724D6BFFEC062CAFB4F922FD2682D6" baseAuthorityName="Goldfuss" baseAuthorityYear="1840" box="[480,706,1729,1750]" class="Bivalvia" family="Mactromyidae" genus="Paracyclas" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="13" pageNumber="434" phylum="Mollusca" rank="species" species="proavia">
<emphasis id="B906EAFAFFEC062CAFB4F922FD2682D6" box="[480,706,1729,1750]" italics="true" pageId="13" pageNumber="434">Paracyclas proavia</emphasis>
</taxonomicName>
from 
<collectingCountry id="F3657678FFEC062CAEF6F903FEE882F5" box="[162,268,1760,1781]" name="Germany" pageId="13" pageNumber="434">Germany</collectingCountry>
do have an elongate and detached anterior adductor scar with a shape similar to modern lucinids (
<figureCitation id="13492A6DFFEC062CAF4DF8FEFE8C8333" box="[281,360,1821,1843]" captionStart="Figure 14" captionStartId="14.[142,220,1647,1666]" captionTargetBox="[302,1262,1004,1614]" captionTargetId="figure-198@14.[302,1263,1002,1614]" captionTargetPageId="14" captionText="Figure 14. Internal mould of Paracyclas proavia (Goldfuss, 1840) from the Devonian, Eifel, Germany (BMNH Pal. Department L25554). Shell length = 56 mm. A, right side, anterior adductor scar arrowed; B, detail of anterior adductor scar showing ventral detachment from pallial line. aas, anterior adductor muscle scar; pl, pallial line." figureDoi="http://doi.org/10.5281/zenodo.4687517" httpUri="https://zenodo.org/record/4687517/files/figure.png" pageId="13" pageNumber="434">Fig. 14</figureCitation>
). 
<bibRefCitation id="EFE34B19FFEC062CAFDEF8FEFD5B8333" author="Zong-Jie F &amp; Cope JCW" box="[394,703,1821,1843]" pageId="13" pageNumber="434" pagination="1121 - 1158" refId="ref10728" refString="Zong-Jie F, Cope JCW. 2004. Early Ordovician bivalves from Dali, West Yunnan, China. Palaeontology 47: 1121 - 1158." type="journal article" year="2004">Zong-Jie &amp; Cope (2004)</bibRefCitation>
have recently described a much earlier 
<taxonomicName id="4C724D6BFFEC062CAC61F8D8FD4B8350" authorityName="Hall" authorityYear="1843" box="[565,687,1851,1872]" class="Bivalvia" family="Mactromyidae" genus="Paracyclas" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="13" pageNumber="434" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEC062CAC61F8D8FD4B8350" box="[565,687,1851,1872]" italics="true" pageId="13" pageNumber="434">Paracyclas</emphasis>
</taxonomicName>
species from the early Ordovician of 
<collectingCountry id="F3657678FFEC062CAC4CF8B9FD848370" box="[536,608,1882,1904]" name="China" pageId="13" pageNumber="434">China</collectingCountry>
, but unfortunately, no internal details are available. Our conclusion is that the 
<taxonomicName id="4C724D6BFFEC062CAA53FF01FB7C84F8" authorityName="P.A.Johnston" authorityYear="1993" box="[1031,1176,226,248]" class="Bivalvia" family="Paracyclidae" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="13" pageNumber="434" phylum="Mollusca" rank="family">Paracyclidae</taxonomicName>
contains some fossils with lucinid characters, but all need further critical study of muscle scars and hinges. A further undoubted lucinid from the Palaeozoic is 
<taxonomicName id="4C724D6BFFEC062CAB73FEDDFB1E8572" authority="Termier &amp; Termier, 1977" authorityName="Termier &amp; Termier" authorityYear="1977" class="Bivalvia" family="Lucinidae" genus="Gigantocyclus" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="13" pageNumber="434" phylum="Mollusca" rank="species" species="zidensis">
<emphasis id="B906EAFAFFEC062CAB73FEDDFC298572" italics="true" pageId="13" pageNumber="434">Gigantocyclus zidensis</emphasis>
Termier &amp; Termier, 1977
</taxonomicName>
from the Permian of 
<collectingCountry id="F3657678FFEC062CADFAFE98FBEC8591" box="[942,1032,379,401]" name="Tunisia" pageId="13" pageNumber="434">Tunisia</collectingCountry>
. This was better described and illustrated by 
<bibRefCitation id="EFE34B19FFEC062CADB1FE79FB0985B0" author="Boyd DW &amp; Newell ND" box="[997,1261,410,432]" pageId="13" pageNumber="434" pagination="1 - 22" refId="ref8339" refString="Boyd DW, Newell ND. 1979. Permian pelecypods from Tunisia. American Museum Novitates 2686: 1 - 22." type="journal article" year="1979">Boyd &amp; Newell (1979)</bibRefCitation>
who compared it with living 
<taxonomicName id="4C724D6BFFEC062CAD8DFE5AFBAB85CE" baseAuthorityName="Gros, Liberge &amp; Felbeck" baseAuthorityYear="2003" box="[985,1103,441,462]" class="Bivalvia" family="Lucinidae" genus="Anodontia" kingdom="Animalia" order="Lucinoida" pageId="13" pageNumber="434" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEC062CAD8DFE5AFBAB85CE" box="[985,1103,441,462]" italics="true" pageId="13" pageNumber="434">Anodontia</emphasis>
</taxonomicName>
.
</paragraph>
<paragraph id="8BCD36E8FFEC062CAD07FE3BFBE68687" blockId="13.[826,1443,195,647]" pageId="13" pageNumber="434">
In summary, the Palaeozoic record of 
<taxonomicName id="4C724D6BFFEC062CAB46FE34FA6785ED" box="[1298,1411,471,493]" class="Bivalvia" family="Lucinidae" kingdom="Animalia" order="Lucinoida" pageId="13" pageNumber="434" phylum="Mollusca" rank="family">Lucinidae</taxonomicName>
is rather meagre but fossils with convincing lucinid characters date from Silurian and younger rocks. Some 
<taxonomicName id="4C724D6BFFEC062CADD5FDD0FC1F8648" authorityName="Hall" authorityYear="1843" box="[897,1019,563,584]" class="Bivalvia" family="Mactromyidae" genus="Paracyclas" higherTaxonomySource="GBIF" kingdom="Animalia" order="Lucinida" pageId="13" pageNumber="434" phylum="Mollusca" rank="genus">
<emphasis id="B906EAFAFFEC062CADD5FDD0FC1F8648" box="[897,1019,563,584]" italics="true" pageId="13" pageNumber="434">Paracyclas</emphasis>
</taxonomicName>
species are common at certain horizons in the Devonian (
<bibRefCitation id="EFE34B19FFEC062CAA18FDB1FB3A8668" author="Bailey JB" box="[1100,1246,594,616]" pageId="13" pageNumber="434" pagination="193 - 326" refId="ref8043" refString="Bailey JB. 1983. Middle Devonian Bivalvia from the Solsville Member (Marcellus Formation), central New York State. Bulletin of the American Museum of Natural History 174: 193 - 326." type="journal article" year="1983">Bailey, 1983</bibRefCitation>
), but all species need reappraisal.
</paragraph>
</subSubSection>
</treatment>
</document>