treatments-xml/data/03/90/87/039087D7C03A4609FF68F8E9FB4D377E.xml

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<mods:title id="80EC0D12252F5CE61CBB82D8D8AB48B2">Revision of the Bivalvia from the Upper Jurassic Reuchenette Formation, Northwest Switzerland — Ostreoidea</mods:title>
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<treatment id="039087D7C03A4609FF68F8E9FB4D377E" ID-DOI="http://doi.org/10.5281/zenodo.6102704" ID-GBIF-Taxon="127377107" ID-Zenodo-Dep="6102704" LSID="urn:lsid:zoobank.org:act:37F96388-804D-4814-9720-5CBAAE14C6C5" httpUri="http://treatment.plazi.org/id/039087D7C03A4609FF68F8E9FB4D377E" lastPageId="41" lastPageNumber="42" pageId="35" pageNumber="36">
<subSubSection id="C323654AC03A4604FF68F8E9FDE13057" lastPageId="36" lastPageNumber="37" pageId="35" pageNumber="36" type="nomenclature">
<paragraph id="8B8636C1C03A4603FF68F8E9FC903447" blockId="35.[151,867,1834,1893]" box="[151,867,1834,1860]" pageId="35" pageNumber="36">
<heading id="D0CE81ADC03A4603FF68F8E9FC903447" bold="true" box="[151,867,1834,1860]" fontSize="11" level="1" pageId="35" pageNumber="36" reason="1">
<emphasis id="B94DEAD3C03A4603FF68F8E9FC903447" bold="true" box="[151,867,1834,1860]" pageId="35" pageNumber="36">
<taxonomicName id="4C394D42C03A4603FF68F8E9FEDD3447" box="[151,302,1834,1860]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="35" pageNumber="36" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C03A4603FF68F8E9FEDD3447" bold="true" box="[151,302,1834,1860]" italics="true" pageId="35" pageNumber="36">Helvetostrea</emphasis>
</taxonomicName>
<taxonomicNameLabel id="A27E57A8C03A4603FECAF8E9FE743447" box="[309,391,1834,1860]" pageId="35" pageNumber="36" rank="genus">n. gen.</taxonomicNameLabel>
<taxonomicName id="4C394D42C03A4603FE70F8E9FC903447" authority="Thurmann &amp; Etallon, 1862" authorityName="Thurmann &amp; Etallon" authorityYear="1862" box="[399,867,1834,1860]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="35" pageNumber="36" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03A4603FE70F8E9FE073447" bold="true" box="[399,500,1834,1860]" italics="true" pageId="35" pageNumber="36">sequana</emphasis>
(Thurmann &amp; 
<bibRefCitation id="EFA84B30C03A4603FD4AF8E9FCA83447" author="Etallon" box="[693,859,1834,1860]" pageId="35" pageNumber="36" refString="Etallon, A. (1862) Etudes paleontologique sur le Haut-Jura. Memoires de la Societe d'Emulation du Departement du Doubs, Serie 3., 6, 53 - 260." type="journal article" year="1862">Etallon, 1862</bibRefCitation>
)
</taxonomicName>
</emphasis>
</heading>
</paragraph>
<paragraph id="8B8636C1C03A4603FF68F88FFD063466" blockId="35.[151,867,1834,1893]" box="[151,757,1868,1893]" pageId="35" pageNumber="36">
<figureCitation id="13022A44C03A4603FF68F88FFEED3466" box="[151,286,1868,1893]" captionStart-0="FIGURE 14" captionStart-1="FIGURE 15" captionStart-2="FIGURE 16" captionStartId-0="35.[151,250,1639,1661]" captionStartId-1="37.[151,250,1866,1888]" captionStartId-2="38.[151,250,1505,1527]" captionTargetBox-0="[189,1399,1165,1615]" captionTargetBox-1="[151,1436,807,1844]" captionTargetBox-2="[151,1436,195,1480]" captionTargetId-0="figure@35.[186,1401,1161,1618]" captionTargetId-1="figure@37.[151,1436,807,1844]" captionTargetId-2="figure@38.[151,1436,195,1480]" captionTargetPageId-0="35" captionTargetPageId-1="37" captionTargetPageId-2="38" captionText-0="FIGURE 14. Helvetostrea n. gen. sequana (Thurmann &amp; Etallon, 1862). Specimens attached to each other (Pl. 11.1 a – d), CTD- TCH 002 - 306, Tchâfouè near Courtedoux, Upper Kimmeridgian, mutabilis Zone: 1, LV, interior (306 a); 2, same LV, anterior view; 3, RV (306 b), served as settling object for LV of Fig. 14.1; scale x 1; 4, juvenile LV (306 c), posteriorly attached to LV (306 a)." captionText-1="FIGURE 15. Helvetostrea n. gen. sequana (Thurmann &amp; Etallon, 1862). 1. Lectotype, refigured from Thurmann &amp; Etallon (1862, pl. 39, fig. 1); LV attached on other specimens of the same species, Bressaucourt near Chevenez (Canton Jura), Upper Oxfordian. 2 – 5. LV, CTD-SCR 003 - 1237, Sur Combe Ronde (bed 2400), Upper Kimmeridgian, mutabilis Zone: 2, interior; 3, lateral; 4, ventral view into the umbonal cavity with cross-sectional shape of ligament area; 5, posterior side view, with distinct angle (52 °) between commissure and ligament area. Scale bars 10 mm." captionText-2="FIGURE 16. Helvetostrea? caprina (Rollier, 1917) and H. oxfordiana (Rollier, 1917). 1. “ Ostrea ” caprina, refigured from Rollier (1917, pl. 39, fig. 2), LV, from Gösgen (Aargau), NE Switzerland (Geissberg Member, Late Oxfordian). 2 – 6.? Helvetostrea n. gen. caprina, same specimen as Fig. 16.1, here designated as lectotype, coll. ETHZ, Ve. S. 4563: 2, LV interior, hinge area poorly drawn in the original figure (compare Fig. 16.1); 3, LV, lateral; 4, RV, interior; 5, RV, lateral; ETH Zürich, photos by Dr. Pika-Biolzi (Zürich), specimen not whitened; 6. Lectotype, anterolateral (both valves re-articulated), refigured from Rollier (1917, pl. 40, fig. 2 b). 7 – 9. Helvetostrea oxfordiana. Figured bivalved type specimen of Ostrea oxfordiana, cf. Rollier 1917, pl. 40, fig. 1 a – c, ETHZ Ve. S. 5146, Klein-Kembs (Kleinkems) near Lörrach (Baden- Württemberg), Germany (&quot; Terrain à Chailles &quot;, Lower Oxfordian, Cardioceras cordatum Zone: 7, LV, interior; 8, LV ventral view; 9, RV lateral. Scale bars 10 mm." httpUri-0="https://zenodo.org/record/288048/files/figure.png" httpUri-1="https://zenodo.org/record/288049/files/figure.png" httpUri-2="https://zenodo.org/record/288050/files/figure.png" pageId="35" pageNumber="36">Figs. 14–16</figureCitation>
; Pl. 4.7–9; Pl. 11.1–5; Pl. 12.1–2; Pl. 20.2
</paragraph>
<paragraph id="8B8636C1C03A4603FF60F866FC9934B8" blockId="35.[159,895,1957,2020]" box="[159,874,1957,1979]" pageId="35" pageNumber="36">
? 1848 
<taxonomicName id="4C394D42C03A4603FEA8F865FE0534B8" box="[343,502,1958,1979]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="35" pageNumber="36" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03A4603FEA8F865FE0534B8" box="[343,502,1958,1979]" italics="true" pageId="35" pageNumber="36">Ostrea sequana</emphasis>
</taxonomicName>
—Dufrénoy &amp; de Beaumont: p. 594.
</paragraph>
<paragraph id="8B8636C1C03A4603FF19F80DFC8C34E7" blockId="35.[159,895,1957,2020]" box="[230,895,1998,2020]" pageId="35" pageNumber="36">
1852a 
<taxonomicName id="4C394D42C03A4603FEA8F80CFE0A34E7" authority="Sequana" authorityName="Sequana" box="[343,505,1999,2020]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="35" pageNumber="36" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03A4603FEA8F80CFE0A34E7" box="[343,505,1999,2020]" italics="true" pageId="35" pageNumber="36">Ostrea Sequana</emphasis>
</taxonomicName>
nob.—Thurmann: p. 213 (nom. nud.).
</paragraph>
<paragraph id="8B8636C1C03D4604FF19FF63FCA433DC" blockId="36.[159,1126,160,512]" pageId="36" pageNumber="37">
1854 
<taxonomicName id="4C394D42C03D4604FEA8FF62FDD333B5" authority="Sequana Th." authorityName="Sequana Th." box="[343,544,160,182]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03D4604FEA8FF62FE0A33B5" box="[343,505,161,182]" italics="true" pageId="36" pageNumber="37">Ostrea Sequana</emphasis>
Th.
</taxonomicName>
—Thurmann: p. 354 (nom. nud.). 1858 
<taxonomicName id="4C394D42C03D4604FEA8FF09FDBB33DC" authority="Thurm." authorityName="Thurm." box="[343,584,201,223]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03D4604FEA8FF09FE0433DC" box="[343,503,202,223]" italics="true" pageId="36" pageNumber="37">Ostrea sequana</emphasis>
Thurm.
</taxonomicName>
—Oppel: p. 150, 164, 165.
</paragraph>
<paragraph id="8B8636C1C03D4604FF19FF31FD2D3231" blockId="36.[159,1126,160,512]" pageId="36" pageNumber="37">
1861 
<taxonomicName id="4C394D42C03D4604FEA8FF30FDDA320B" authority="Sequana, Th." authorityName="Sequana, Th." box="[343,553,242,264]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03D4604FEA8FF30FE0A320B" box="[343,505,243,264]" italics="true" pageId="36" pageNumber="37">Ostrea Sequana</emphasis>
, Th.
</taxonomicName>
—Thurmann &amp; Etallon: p. 37, 64. 1862 
<taxonomicName id="4C394D42C03D4604FEA8FEDFFDD43231" authority="Sequana, Th." authorityName="Sequana, Th." box="[343,551,284,306]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03D4604FEA8FEDFFE0A3232" box="[343,505,284,305]" italics="true" pageId="36" pageNumber="37">Ostrea Sequana</emphasis>
, Th.
</taxonomicName>
—Etallon: p. 407.
</paragraph>
<paragraph id="8B8636C1C03D4604FF60FE86FCD73287" blockId="36.[159,1126,160,512]" pageId="36" pageNumber="37">
* 1862 
<taxonomicName id="4C394D42C03D4604FEA8FE85FDD13258" authority="Th." authorityName="Th." box="[343,546,325,347]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03D4604FEA8FE85FE053258" box="[343,502,326,347]" italics="true" pageId="36" pageNumber="37">Ostrea sequana</emphasis>
, Th.
</taxonomicName>
—Thurmann &amp; Etallon: p. 270, pl. 38, fig. 6. 1870 
<taxonomicName id="4C394D42C03D4604FEA8FEACFDD53287" authority="Sequana, Th." authorityName="Sequana, Th." box="[343,550,366,388]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03D4604FEA8FEACFE0A3287" box="[343,505,367,388]" italics="true" pageId="36" pageNumber="37">Ostrea Sequana</emphasis>
, Th.
</taxonomicName>
—Greppin, J.-B.: p. 104.
</paragraph>
<paragraph id="8B8636C1C03D4604FF19FE5BFD2832AD" blockId="36.[159,1126,160,512]" box="[230,731,408,430]" pageId="36" pageNumber="37">
1887 
<taxonomicName id="4C394D42C03D4604FEA8FE5AFDED32AD" authority="Th." authorityName="Th." box="[343,542,408,430]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03D4604FEA8FE5AFE0432AD" box="[343,503,409,430]" italics="true" pageId="36" pageNumber="37">Ostrea sequana</emphasis>
Th.
</taxonomicName>
—Roberts: p. 238.
</paragraph>
<paragraph id="8B8636C1C03D4604FF19FE02FCAD32D4" blockId="36.[159,1126,160,512]" box="[230,862,449,471]" pageId="36" pageNumber="37">
1917 
<taxonomicName id="4C394D42C03D4604FEA8FE01FCFC32D4" authority="Sequana (Thurm.) Etallon-Rollier" authorityName="Sequana (Thurm.) Etallon-Rollier" box="[343,783,449,471]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03D4604FEA8FE01FE0A32D4" box="[343,505,450,471]" italics="true" pageId="36" pageNumber="37">Ostrea Sequana</emphasis>
(Thurm.) Etallon—Rollier
</taxonomicName>
: p. 589.
</paragraph>
<paragraph id="8B8636C1C03D4604FF19FE29FB953103" blockId="36.[159,1126,160,512]" box="[230,1126,490,512]" pageId="36" pageNumber="37">
1971 
<taxonomicName id="4C394D42C03D4604FEA8FE28FD303103" authority="Thurmann, 1862" authorityName="Thurmann" authorityYear="1862" box="[343,707,490,512]" class="Bivalvia" family="Gryphaeidae" genus="Liostrea" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03D4604FEA8FE28FDF53103" box="[343,518,491,512]" italics="true" pageId="36" pageNumber="37">Liostrea sequana</emphasis>
(Thurmann, 1862)
</taxonomicName>
—Pugaczewska: p. 257, pl. 16, figs. 1–4.
</paragraph>
<paragraph id="8B8636C1C03D4604FF68FDFCFEBE31C6" blockId="36.[151,1437,575,2005]" pageId="36" pageNumber="37">
<emphasis id="B94DEAD3C03D4604FF68FDFCFE08315B" bold="true" box="[151,507,575,600]" pageId="36" pageNumber="37">
<typeStatus id="54828863C03D4604FF68FDFCFEFE315B" box="[151,269,575,600]" pageId="36" pageNumber="37" type="lectotype">Lectotype</typeStatus>
(designated herein)
</emphasis>
. 
<taxonomicName id="4C394D42C03D4604FDF5FD83FC04315B" authority="Thurmann &amp; Etallon, 1862" authorityName="Thurmann &amp; Etallon" authorityYear="1862" box="[522,1015,575,600]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03D4604FDF5FD83FD49315B" box="[522,698,576,600]" italics="true" pageId="36" pageNumber="37">Ostrea sequana</emphasis>
Thurmann &amp; 
<bibRefCitation id="EFA84B30C03D4604FCA3FDFCFC04315B" author="Etallon" box="[860,1015,575,600]" pageId="36" pageNumber="37" refString="Etallon, A. (1862) Etudes paleontologique sur le Haut-Jura. Memoires de la Societe d'Emulation du Departement du Doubs, Serie 3., 6, 53 - 260." type="journal article" year="1862">Etallon, 1862</bibRefCitation>
</taxonomicName>
, p. 270–271, pl. 39, fig. 1, left valve. The 
<typeStatus id="54828863C03D4604FF31FDA6FF0D317E" box="[206,254,613,637]" pageId="36" pageNumber="37">type</typeStatus>
specimen (refigured on Fig. 15.1) was not traceable in the MJSN Porrentruy and is apparently lost. However, ICZN Article 74.4 permits the designation of an illustration as 
<typeStatus id="54828863C03D4604FC2CFD44FBC931A3" box="[979,1082,647,672]" pageId="36" pageNumber="37" type="lectotype">lectotype</typeStatus>
when the 
<typeStatus id="54828863C03D4604FB4FFD4BFB1331A3" box="[1200,1248,648,672]" pageId="36" pageNumber="37">type</typeStatus>
specimen is lost or not traceable.
</paragraph>
<paragraph id="8B8636C1C03D4604FF38FD0CFDE13057" blockId="36.[151,1437,575,2005]" pageId="36" pageNumber="37">
Combe d'Essert-Tainie, a gorge (not traceable on the available maps of the region) but situated most likely northwest of Bressaucourt (near Chevenez, Ajoie, Canton Jura), &quot;Marnes à Astartes&quot; (now Bure Member, Vellerat Formation, 
<taxonomicName id="4C394D42C03D4604FEE3FCD4FD523033" authority="Zone" authorityName="Zone" box="[284,673,791,816]" class="Cephalopoda" family="Aspidoceratidae" genus="Epipeltoceras" higherTaxonomySource="CoL" kingdom="Animalia" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="bimammatum">
<emphasis id="B94DEAD3C03D4604FEE3FCD4FDAA3033" box="[284,601,791,816]" italics="true" pageId="36" pageNumber="37">Epipeltoceras bimammatum</emphasis>
Zone
</taxonomicName>
), Upper Oxfordian; coordinates: 
<geoCoordinate id="EE0D5006C03D4604FBE1FCD4FB353033" box="[1054,1222,791,816]" direction="north" orientation="latitude" pageId="36" pageNumber="37" precision="1" value="47.388157">47°23'17.36''N</geoCoordinate>
, 
<geoCoordinate id="EE0D5006C03D4604FB2BFCD4FA9F3033" box="[1236,1388,791,816]" direction="east" orientation="longitude" pageId="36" pageNumber="37" precision="1" value="7.037772">7°02'15.98''E</geoCoordinate>
; the coordinates refer to Bressaucourt.
</paragraph>
</subSubSection>
<subSubSection id="C323654AC03D4604FF38FC9CFBFA36BB" pageId="36" pageNumber="37" type="materials_examined">
<paragraph id="8B8636C1C03D4604FF38FC9CFEF5370B" blockId="36.[151,1437,575,2005]" pageId="36" pageNumber="37">
<emphasis id="B94DEAD3C03D4604FF38FC9CFEC5307B" bold="true" box="[199,310,863,888]" pageId="36" pageNumber="37">Material.</emphasis>
Lectotye (see above) and 
<typeStatus id="54828863C03D4604FD98FC9CFD0D307B" box="[615,766,863,888]" pageId="36" pageNumber="37" type="paralectotype">paralectotype</typeStatus>
(AC1766, B.4.15.4.1)—Only one small rock-sample from the 
<typeStatus id="54828863C03D4604FF3DFC46FF01309E" box="[194,242,901,925]" pageId="36" pageNumber="37">type</typeStatus>
series was traceable in the 
<collectionCode id="ED28AE04C03D4604FDCEFC47FD8A309F" box="[561,633,900,924]" pageId="36" pageNumber="37">MJSN</collectionCode>
Porrentruy. The small piece of grey, dense limestone contains several cross-sections of weathered and only partially preserved specimens exhibiting the typical hollow chambers of 
<taxonomicName id="4C394D42C03D4604FA7EFC6AFF0730E7" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03D4604FA7EFC6AFF0730E7" italics="true" pageId="36" pageNumber="37">H. sequana</emphasis>
</taxonomicName>
but no other shell details. Due to the poor preservation none of the specimens is suitable to be chosen as 
<typeStatus id="54828863C03D4604FF68FC2CFEF1370B" box="[151,258,1007,1032]" pageId="36" pageNumber="37" type="lectotype">lectotype</typeStatus>
.
</paragraph>
<paragraph id="8B8636C1C03D4604FF38FBD7FB7937BE" blockId="36.[151,1437,575,2005]" pageId="36" pageNumber="37">
The original label of the 
<typeStatus id="54828863C03D4604FE1CFBD7FD89372E" box="[483,634,1044,1069]" pageId="36" pageNumber="37" type="paralectotype">paralectotype</typeStatus>
refers to 
<taxonomicName id="4C394D42C03D4604FD17FBD6FC6B372F" box="[744,920,1045,1068]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03D4604FD17FBD6FC6B372F" box="[744,920,1045,1068]" italics="true" pageId="36" pageNumber="37">Ostrea sequana</emphasis>
</taxonomicName>
nob, Th. 1846, from Bressaucourt. However, according to Etallon’s introduction to the “Lethea 
<taxonomicName id="4C394D42C03D4604FD22FBF4FC923753" box="[733,865,1079,1104]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="bruntrutana">bruntrutana</taxonomicName>
” (
<bibRefCitation id="EFA84B30C03D4604FC84FBF4FAF53753" author="Thurmann" box="[891,1286,1079,1104]" pageId="36" pageNumber="37" refString="Thurmann, J. &amp; Etallon, A. (1861 - 1864), Lethea Bruntrutana ou Etudes paleontologiques et stratigraphiques sur le Jura Bernois et en particulier les environs de Porrentruy. Denkschriften der Schweizerischen Naturforschenden Gesellschaft, 18 - 20, 1 - 146 (1861), 147 - 354 (1862), 355 - 500 (1864)." type="journal article" year="1861" yearSuffix="p">Thurmann and Etallon, 1861, p. 3</bibRefCitation>
), the species name was initially a 
<emphasis id="B94DEAD3C03D4604FE69FB9EFDC93776" box="[406,570,1116,1141]" italics="true" pageId="36" pageNumber="37">nomen nudum</emphasis>
based on an unpublished note by Thurmann (1848) titled “Sur l’ 
<taxonomicName id="4C394D42C03D4604FAAEFB9EFF07379B" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03D4604FAAEFB9EFF07379B" italics="true" pageId="36" pageNumber="37">Ostrea sequana</emphasis>
</taxonomicName>
”. Therefore, Dufrénoy &amp; de Beaumont (1848) and Thurmann (1852, 1854) can only have referred to this unpublished name, whereas the valid introduction is given in Thurmann &amp; 
<bibRefCitation id="EFA84B30C03D4604FC1FFB67FB7537BE" box="[992,1158,1188,1213]" pageId="36" pageNumber="37" refString="Etallon, A. (1862) Etudes paleontologique sur le Haut-Jura. Memoires de la Societe d'Emulation du Departement du Doubs, Serie 3., 6, 53 - 260." type="journal article">Etallon (1862)</bibRefCitation>
.
</paragraph>
<paragraph id="8B8636C1C03D4604FF38FB04FA8D3673" blockId="36.[151,1437,575,2005]" pageId="36" pageNumber="37">
Others—One small (“juvenile”) 
<collectionCode id="ED28AE04C03D4604FDBDFB0BFD9637DC" box="[578,613,1224,1247]" pageId="36" pageNumber="37">LV</collectionCode>
from the basal Banné Member (horizon 300, 
<emphasis id="B94DEAD3C03D4604FB74FB04FB0837E3" box="[1163,1275,1223,1248]" italics="true" pageId="36" pageNumber="37">cymodoce</emphasis>
Zone, Lower Kimmeridgian) of Vâ Tche Tchâ near Courtedoux (
<collectionCode id="ED28AE04C03D4604FD15FB2FFCD73606" box="[746,804,1260,1285]" httpUri="http://grbio.org/cool/mm8z-8ppw" name="VTT Biotechnology, Culture Collection" pageId="36" pageNumber="37">VTT</collectionCode>
001-1169b, Pl. 11.3) and more than 20 larger (“adult”) specimens (mostly 
<collectionCode id="ED28AE04C03D4604FE89FAD3FE6A3624" box="[374,409,1296,1319]" pageId="36" pageNumber="37">LV</collectionCode>
, Pl. 4.7–8; Pl. 11; Pl. 12.1–2) from the “Virgulien” facies of the uppermost Courtedoux Member, Upper Kimmeridgian (horizons 2400–3500, 
<emphasis id="B94DEAD3C03D4604FD09FAF7FCAC364E" box="[758,863,1332,1357]" italics="true" pageId="36" pageNumber="37">mutabilis</emphasis>
Zone, 
<emphasis id="B94DEAD3C03D4604FC52FAF7FBCB364E" box="[941,1080,1332,1357]" italics="true" pageId="36" pageNumber="37">lallierianum</emphasis>
Subzone) of Sur Combe Ronde (SCR) and Tchâfouè (TCH) near Courtedoux. The best preserved specimens are listed in the Appendix, 
<tableCitation id="C6BB037AC03D4604FADBFA94FA893673" box="[1316,1402,1367,1392]" captionStart="TABLE 5" captionStartId="71.[151,239,152,175]" captionTargetBox="[159,1365,202,968]" captionTargetPageId="71" captionText="TABLE 5. Helvetostrea n. gen. sequana (Thurmann &amp; Étallon, 1862)." httpUri="http://table.plazi.org/id/DF466649C05E4667FF68FF5BFC7A33AC" pageId="36" pageNumber="37" tableUuid="DF466649C05E4667FF68FF5BFC7A33AC">Table 5</tableCitation>
.
</paragraph>
<paragraph id="8B8636C1C03D4604FF38FABEFBFA36BB" blockId="36.[151,1437,575,2005]" pageId="36" pageNumber="37">
Two small and thin-shelled specimens labelled as 
<taxonomicName id="4C394D42C03D4604FD07FABEFBD03696" authority="Thurmann" authorityName="Thurmann" box="[760,1059,1404,1429]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="36" pageNumber="37" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03D4604FD07FABEFC543697" box="[760,935,1405,1428]" italics="true" pageId="36" pageNumber="37">Ostrea sequana</emphasis>
Thurmann
</taxonomicName>
(
<collectionCode id="ED28AE04C03D4604FBCDFABFFB883697" box="[1074,1147,1404,1428]" pageId="36" pageNumber="37">MJSN</collectionCode>
S.1337, A.2.18.2.4) from the Koby collection in the 
<collectionCode id="ED28AE04C03D4604FE3EFA63FDFA36BB" box="[449,521,1440,1464]" pageId="36" pageNumber="37">MJSN</collectionCode>
belong to an undetermined liostreine species.
</paragraph>
</subSubSection>
<subSubSection id="C323654AC03D4607FF38FA07FE9530EE" lastPageId="39" lastPageNumber="40" pageId="36" pageNumber="37" type="description">
<paragraph id="8B8636C1C03D4604FF38FA07FAF73593" blockId="36.[151,1437,575,2005]" pageId="36" pageNumber="37">
<emphasis id="B94DEAD3C03D4604FF38FA07FEA236DE" bold="true" box="[199,337,1476,1501]" pageId="36" pageNumber="37">Description</emphasis>
. Shape, size—Highly variable including subrectangular, trapeziform, subtrigonal shapes. LV sometimes much elongated in height, always higher than RV, usually moderately inflated, greatest convexity close to umbo. Attachment area commonly restricted to umbonal region, medium-sized in separately growing individuals (Pl. 4.7, 9a; Pl. 11.2, 4a) or large when growing in clusters (Pl. 4.8, Pl. 12.2a). RV (only two specimens known; Pl. 11.1b; Appendix, 
<tableCitation id="C6BB037AC03D4604FE21F997FDC2356E" box="[478,561,1620,1645]" captionStart="TABLE 5" captionStartId="71.[151,239,152,175]" captionTargetBox="[159,1365,202,968]" captionTargetPageId="71" captionText="TABLE 5. Helvetostrea n. gen. sequana (Thurmann &amp; Étallon, 1862)." httpUri="http://table.plazi.org/id/DF466649C05E4667FF68FF5BFC7A33AC" pageId="36" pageNumber="37" tableUuid="DF466649C05E4667FF68FF5BFC7A33AC">Table 5</tableCitation>
) relatively small and flat, with subrectangular shape and slightly convex, shell thickness at the ventral margin 
<quantity id="4CC19B24C03D4604FE0AF9BBFDA6358C" box="[501,597,1656,1680]" metricMagnitude="-3" metricUnit="m" metricValue="3.5" metricValueMax="4.0" metricValueMin="3.0" pageId="36" pageNumber="37" unit="mm" value="3.5" valueMax="4.0" valueMin="3.0">3–4 mm</quantity>
. Observed maximum size 
<quantity id="4CC19B24C03D4604FC82F9BBFC47358C" box="[893,948,1656,1680]" metricMagnitude="-2" metricUnit="m" metricValue="8.0" pageId="36" pageNumber="37" unit="cm" value="8.0">8 cm</quantity>
(height) (Appendix, 
<tableCitation id="C6BB037AC03D4604FB5EF9B4FB063593" box="[1185,1269,1655,1680]" captionStart="TABLE 5" captionStartId="71.[151,239,152,175]" captionTargetBox="[159,1365,202,968]" captionTargetPageId="71" captionText="TABLE 5. Helvetostrea n. gen. sequana (Thurmann &amp; Étallon, 1862)." httpUri="http://table.plazi.org/id/DF466649C05E4667FF68FF5BFC7A33AC" pageId="36" pageNumber="37" tableUuid="DF466649C05E4667FF68FF5BFC7A33AC">Table 5</tableCitation>
).
</paragraph>
<paragraph id="8B8636C1C03D4604FF38F95FFEAF3423" blockId="36.[151,1437,575,2005]" pageId="36" pageNumber="37">Sculpture—LV with thick growth lamellae, irregular, imbricating (spaces between squamae filled with sediment, later overgrown by new shell foils); occasionally with few undulating radial ribs; shell surface of folds and depressions, in some cases pustular. Single RV relatively smooth, with few weak commarginal furrows and fine growth lines.</paragraph>
<paragraph id="8B8636C1C03D4604FF38F8EFFBBC34D6" blockId="36.[151,1437,575,2005]" pageId="36" pageNumber="37">
Ligament area—Overall growing ventralwards, ostreoid, with a straight or slightly undulating resilifer, rarely anteriorly directed (Fig. 14.3–4; Pl. 11.2). LV resilifer deep, flanked by equally broad, elevated bourrelets (Fig. 15.2); outer bourrelet flanks dipping steeply towards commissure (
<emphasis id="B94DEAD3C03D4604FC5DF8B6FC37348F" box="[930,964,1909,1932]" italics="true" pageId="36" pageNumber="37">ca.</emphasis>
30–60°) (Pl. 11.4a; Fig. 15.5), confined anteriorly and posteriorly by deep narrow troughs (Fig. 15.2,4; Pl. 11.2). RV resilifer supported by a callous-like shell buttress (sensu 
<bibRefCitation id="EFA84B30C03D4604FE80F87FFDE134D7" author="Stenzel" box="[383,530,1980,2005]" pageId="36" pageNumber="37" refString="Stenzel, H. B. (1971) Oysters. In: Moore, R. C. (Eds.), Treatise on Invertebrate Paleontology. Part N, Mollusca 6 (Bivalvia). Vol. 3. Geological Society of America, University of Kansas, Boulder, pp. N 953 - N 1124." type="journal article" year="1971">Stenzel 1971</bibRefCitation>
, p. N1029, N973, fig. J14a,b) (Fig. 14.3; Pl. 11.1b)
</paragraph>
<paragraph id="8B8636C1C03C4605FF38FF54FEC53266" blockId="37.[151,1437,151,752]" pageId="37" pageNumber="38">
Internal shell characters—LV commissural shelf, dorsally narrow and bounded by inner lateral ridge; shelf broadening ventrally. Posterior adductor scar subcircular to high-oval, dorsally truncated or weakly concave, scar slightly sunken below general depositional surface; position essentially posterodorsal (
<emphasis id="B94DEAD3C03C4605FB97FF22FB7A33FB" box="[1128,1161,225,248]" italics="true" pageId="37" pageNumber="38">ca.</emphasis>
1/3 sub-posterocentral). (Fig. 14.3–4; Fig. 15.2; Pl. 11.1a,b). PAM insertion in RV with projected ventral border (Pl. 11.1b) (buttressed sensu 
<bibRefCitation id="EFA84B30C03C4605FF1FFEE4FE853243" author="Stenzel" box="[224,374,295,320]" pageId="37" pageNumber="38" refString="Stenzel, H. B. (1971) Oysters. In: Moore, R. C. (Eds.), Treatise on Invertebrate Paleontology. Part N, Mollusca 6 (Bivalvia). Vol. 3. Geological Society of America, University of Kansas, Boulder, pp. N 953 - N 1124." type="journal article" year="1971">Stenzel 1971</bibRefCitation>
, p. N1029). Quenstedt muscle scar not seen. Chomata and relict chomata questionable (Pl. 11.3a,b, 5c,d).
</paragraph>
<paragraph id="8B8636C1C03C4605FF38FEACFBCC32D3" blockId="37.[151,1437,151,752]" pageId="37" pageNumber="38">Microstructure—LV with thick regularly to partly complex cross-foliated outer-middle layer; middle-inner layers largely chambered, some (probably originally) hollow (Pl. 12.1a,b), some filled with chalky deposits (mocret); some filled with sediment or diagenetic cement (Pl. 12.2b,c; Pl. 20.2a–d).</paragraph>
<paragraph id="8B8636C1C03C4605FF38FE1FFC1032F6" blockId="37.[151,1437,151,752]" box="[199,995,476,501]" pageId="37" pageNumber="38">Prodissoconch, juvenile—Prodissoconch and early juveniles unknown.</paragraph>
<paragraph id="8B8636C1C03C4605FF38FE3CFEDB31F3" blockId="37.[151,1437,151,752]" pageId="37" pageNumber="38">
<emphasis id="B94DEAD3C03C4605FF38FE3CFEAC311B" bold="true" box="[199,351,511,536]" pageId="37" pageNumber="38">Paleoecology</emphasis>
. At its 
<typeStatus id="54828863C03C4605FE47FDC3FE1B311B" box="[440,488,512,536]" pageId="37" pageNumber="38">type</typeStatus>
locality, the species formed aggregates or small buildups (“framestones”) of up to several decimetres thickness intercalated between coral-bearing, calcareous marls and unfossiliferous marls („Zone Astartienne“); the lateral extensions are unknown. 
<bibRefCitation id="EFA84B30C03C4605FD27FD84FBE33163" author="Thurmann" box="[728,1040,583,608]" pageId="37" pageNumber="38" refString="Thurmann, J. &amp; Etallon, A. (1861 - 1864), Lethea Bruntrutana ou Etudes paleontologiques et stratigraphiques sur le Jura Bernois et en particulier les environs de Porrentruy. Denkschriften der Schweizerischen Naturforschenden Gesellschaft, 18 - 20, 1 - 146 (1861), 147 - 354 (1862), 355 - 500 (1864)." type="journal article" year="1861">Thurmann &amp; Etallon (1861</bibRefCitation>
, p. 37; 1862, p. 271, pl. 39, fig. 1) found the species together with 
<taxonomicName id="4C394D42C03C4605FDD9FDAEFD2E3187" box="[550,733,621,644]" class="Bivalvia" family="Gryphaeidae" genus="Nanogyra" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="37" pageNumber="38" phylum="Mollusca" rank="species" species="nana">
<emphasis id="B94DEAD3C03C4605FDD9FDAEFD2E3187" box="[550,733,621,644]" italics="true" pageId="37" pageNumber="38">Nanogyra nana</emphasis>
</taxonomicName>
(= 
<taxonomicName id="4C394D42C03C4605FCEAFDAEFB673186" authority="Thurmann" authorityName="Thurmann" box="[789,1172,620,645]" class="Bivalvia" family="Gryphaeidae" genus="Exogyra" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="37" pageNumber="38" phylum="Mollusca" rank="species" species="bruntrutana">
<emphasis id="B94DEAD3C03C4605FCEAFDAEFBF83186" box="[789,1035,620,645]" italics="true" pageId="37" pageNumber="38">Exogyra bruntrutana</emphasis>
Thurmann
</taxonomicName>
), for example, in the “Lumachelle à 
<taxonomicName id="4C394D42C03C4605FEBEFD52FDDD31AB" box="[321,558,655,680]" class="Bivalvia" family="Gryphaeidae" genus="Exogyra" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="37" pageNumber="38" phylum="Mollusca" rank="species" species="bruntrutana">
<emphasis id="B94DEAD3C03C4605FEBEFD52FDDD31AB" box="[321,558,655,680]" italics="true" pageId="37" pageNumber="38">Exogyra bruntrutana</emphasis>
</taxonomicName>
et 
<taxonomicName id="4C394D42C03C4605FDB0FD53FD0D31AB" box="[591,766,656,680]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="37" pageNumber="38" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03C4605FDB0FD53FD0D31AB" box="[591,766,656,680]" italics="true" pageId="37" pageNumber="38">Ostrea sequana</emphasis>
</taxonomicName>
”. The species is associated with a diverse coral fauna of the „Zone à polypiers“ (
<bibRefCitation id="EFA84B30C03C4605FE6CFD77FC9131CE" author="Thurmann" box="[403,866,692,717]" pageId="37" pageNumber="38" refString="Thurmann, J. &amp; Etallon, A. (1861 - 1864), Lethea Bruntrutana ou Etudes paleontologiques et stratigraphiques sur le Jura Bernois et en particulier les environs de Porrentruy. Denkschriften der Schweizerischen Naturforschenden Gesellschaft, 18 - 20, 1 - 146 (1861), 147 - 354 (1862), 355 - 500 (1864)." type="journal article" year="1861" yearSuffix="p">Thurmann &amp; Etallon 1861, p. 37, 62</bibRefCitation>
), crinoids (genus 
<taxonomicName id="4C394D42C03C4605FBBDFD77FB3831C8" box="[1090,1227,692,715]" class="Crinoidea" family="Apiocrinitidae" genus="Apiocrinites" higherTaxonomySource="GBIF" kingdom="Animalia" order="Millericrinida" pageId="37" pageNumber="38" phylum="Echinodermata" rank="genus">
<emphasis id="B94DEAD3C03C4605FBBDFD77FB3831C8" box="[1090,1227,692,715]" italics="true" pageId="37" pageNumber="38">Apiocrinites</emphasis>
</taxonomicName>
) and terebratulid brachiopods.
</paragraph>
<caption id="DF466649C03C4605FF68F889FC9534D8" httpUri="https://zenodo.org/record/288049/files/figure.png" pageId="37" pageNumber="38" targetBox="[151,1436,807,1844]" targetPageId="37">
<paragraph id="8B8636C1C03C4605FF68F889FC9534D8" blockId="37.[151,1436,1866,2011]" pageId="37" pageNumber="38">
<emphasis id="B94DEAD3C03C4605FF68F889FEE83463" bold="true" box="[151,283,1866,1888]" pageId="37" pageNumber="38">FIGURE 15</emphasis>
. 
<taxonomicName id="4C394D42C03C4605FED6F889FE593463" box="[297,426,1866,1888]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="37" pageNumber="38" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C03C4605FED6F889FE593463" box="[297,426,1866,1888]" italics="true" pageId="37" pageNumber="38">Helvetostrea</emphasis>
</taxonomicName>
<taxonomicNameLabel id="A27E57A8C03C4605FE4DF889FE083463" box="[434,507,1866,1888]" pageId="37" pageNumber="38" rank="genus">
<emphasis id="B94DEAD3C03C4605FE4DF889FE083463" bold="true" box="[434,507,1866,1888]" pageId="37" pageNumber="38">n. gen.</emphasis>
</taxonomicNameLabel>
<taxonomicName id="4C394D42C03C4605FDFCF888FC783463" authority="Thurmann &amp; Etallon, 1862" authorityName="Thurmann &amp; Etallon" authorityYear="1862" box="[515,907,1866,1888]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="37" pageNumber="38" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03C4605FDFCF888FDA43463" box="[515,599,1867,1888]" italics="true" pageId="37" pageNumber="38">sequana</emphasis>
(Thurmann &amp; Etallon, 1862)
</taxonomicName>
. 
<emphasis id="B94DEAD3C03C4605FC68F889FC573463" bold="true" box="[919,932,1866,1888]" pageId="37" pageNumber="38">1</emphasis>
. Lectotype, refigured from Thurmann &amp; Etallon (1862, pl. 39, fig. 1); LV attached on other specimens of the same species, Bressaucourt near Chevenez (Canton Jura), Upper Oxfordian. 
<emphasis id="B94DEAD3C03C4605FEF3F844FEC1349E" bold="true" box="[268,306,1927,1949]" pageId="37" pageNumber="38">2–5</emphasis>
. LV, CTD-SCR003-1237, Sur Combe Ronde (bed 2400), Upper Kimmeridgian, 
<emphasis id="B94DEAD3C03C4605FB92F844FB38349E" box="[1133,1227,1927,1949]" italics="true" pageId="37" pageNumber="38">mutabilis</emphasis>
Zone: 
<emphasis id="B94DEAD3C03C4605FAEAF844FAD1349E" bold="true" box="[1301,1314,1927,1949]" pageId="37" pageNumber="38">2</emphasis>
, interior; 
<emphasis id="B94DEAD3C03C4605FA76F844FA66349E" bold="true" box="[1417,1429,1927,1949]" pageId="37" pageNumber="38">3</emphasis>
, lateral; 
<emphasis id="B94DEAD3C03C4605FF1BF865FF0334BF" bold="true" box="[228,240,1958,1980]" pageId="37" pageNumber="38">4</emphasis>
, ventral view into the umbonal cavity with cross-sectional shape of ligament area; 
<emphasis id="B94DEAD3C03C4605FBC6F865FBB534BF" bold="true" box="[1081,1094,1958,1980]" pageId="37" pageNumber="38">5</emphasis>
, posterior side view, with distinct angle (52°) between commissure and ligament area. Scale bars 10 mm.
</paragraph>
</caption>
<caption id="DF466649C03F4606FF68FA22FDED35EF" httpUri="https://zenodo.org/record/288050/files/figure.png" pageId="38" pageNumber="39" targetBox="[151,1436,195,1480]" targetPageId="38">
<paragraph id="8B8636C1C03F4606FF68FA22FDED35EF" blockId="38.[151,1436,1505,1772]" pageId="38" pageNumber="39">
<emphasis id="B94DEAD3C03F4606FF68FA22FEE836F4" bold="true" box="[151,283,1505,1527]" pageId="38" pageNumber="39">FIGURE 16</emphasis>
. 
<taxonomicName id="4C394D42C03F4606FED4FA22FE5836F4" box="[299,427,1505,1527]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="38" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C03F4606FED4FA22FE5836F4" box="[299,427,1505,1527]" italics="true" pageId="38" pageNumber="39">Helvetostrea</emphasis>
</taxonomicName>
? 
<taxonomicName id="4C394D42C03F4606FE40FA21FD5D36F4" authority="Rollier, 1917" authorityName="Rollier" authorityYear="1917" box="[447,686,1505,1527]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="38" pageNumber="39" phylum="Mollusca" rank="species" species="caprina">
<emphasis id="B94DEAD3C03F4606FE40FA21FDFD36F4" box="[447,526,1506,1527]" italics="true" pageId="38" pageNumber="39">caprina</emphasis>
(Rollier, 1917)
</taxonomicName>
and 
<taxonomicName id="4C394D42C03F4606FD1AFA21FBEA36F4" authority="Rollier, 1917" authorityName="Rollier" authorityYear="1917" box="[741,1049,1505,1527]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="38" pageNumber="39" phylum="Mollusca" rank="species" species="oxfordiana">
<emphasis id="B94DEAD3C03F4606FD1AFA21FC8636F4" box="[741,885,1505,1527]" italics="true" pageId="38" pageNumber="39">H. oxfordiana</emphasis>
(Rollier, 1917)
</taxonomicName>
. 
<emphasis id="B94DEAD3C03F4606FBDAFA22FBC136F4" bold="true" box="[1061,1074,1505,1527]" pageId="38" pageNumber="39">1</emphasis>
. “ 
<emphasis id="B94DEAD3C03F4606FBB3FA21FB0536F4" box="[1100,1270,1506,1527]" italics="true" pageId="38" pageNumber="39">
<taxonomicName id="4C394D42C03F4606FBB3FA21FB6536F4" box="[1100,1174,1506,1527]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="38" pageNumber="39" phylum="Mollusca" rank="genus">Ostrea</taxonomicName>
” 
<taxonomicName id="4C394D42C03F4606FB58FA21FB0536F4" box="[1191,1270,1506,1527]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="38" pageNumber="39" phylum="Mollusca" rank="species" species="caprina">caprina</taxonomicName>
</emphasis>
, refigured from Rollier (1917, pl. 39, fig. 2), LV, from Gösgen (Aargau), NE Switzerland (Geissberg Member, Late Oxfordian). 
<emphasis id="B94DEAD3C03F4606FA8FFA3CFA663516" bold="true" box="[1392,1429,1535,1557]" pageId="38" pageNumber="39">2–6</emphasis>
.? 
<taxonomicName id="4C394D42C03F4606FF5DF9DDFED03537" box="[162,291,1566,1588]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="38" pageNumber="39" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C03F4606FF5DF9DDFED03537" box="[162,291,1566,1588]" italics="true" pageId="38" pageNumber="39">Helvetostrea</emphasis>
</taxonomicName>
<taxonomicNameLabel id="A27E57A8C03F4606FED2F9DDFE8B3537" box="[301,376,1566,1588]" pageId="38" pageNumber="39" rank="genus">
<emphasis id="B94DEAD3C03F4606FED2F9DDFE8B3537" bold="true" box="[301,376,1566,1588]" pageId="38" pageNumber="39">n. gen.</emphasis>
</taxonomicNameLabel>
<taxonomicName id="4C394D42C03F4606FE7DF9DCFE223537" box="[386,465,1567,1588]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="38" pageNumber="39" phylum="Mollusca" rank="species" species="caprina">
<emphasis id="B94DEAD3C03F4606FE7DF9DCFE223537" box="[386,465,1567,1588]" italics="true" pageId="38" pageNumber="39">caprina</emphasis>
</taxonomicName>
, same specimen as Fig. 16.1, here designated as lectotype, coll. ETHZ, Ve.S. 4563: 
<emphasis id="B94DEAD3C03F4606FAA0F9DDFA983537" bold="true" box="[1375,1387,1566,1588]" pageId="38" pageNumber="39">2</emphasis>
, LV interior, hinge area poorly drawn in the original figure (compare Fig. 16.1); 
<emphasis id="B94DEAD3C03F4606FC5AF9FEFC423550" bold="true" box="[933,945,1597,1619]" pageId="38" pageNumber="39">3</emphasis>
, LV, lateral; 
<emphasis id="B94DEAD3C03F4606FBC8F9FEFBB73550" bold="true" box="[1079,1092,1597,1619]" pageId="38" pageNumber="39">4</emphasis>
, RV, interior; 
<emphasis id="B94DEAD3C03F4606FB28F9FEFB103550" bold="true" box="[1239,1251,1597,1619]" pageId="38" pageNumber="39">5</emphasis>
, RV, lateral; ETH Zürich, photos by Dr. Pika-Biolzi (Zürich), specimen not whitened; 
<emphasis id="B94DEAD3C03F4606FC9BF99FFC833571" bold="true" box="[868,880,1628,1650]" pageId="38" pageNumber="39">6</emphasis>
. Lectotype, anterolateral (both valves re-articulated), refigured from Rollier (1917, pl. 40, fig. 2b). 
<emphasis id="B94DEAD3C03F4606FD6EF9B9FD453593" bold="true" box="[657,694,1658,1680]" pageId="38" pageNumber="39">7–9</emphasis>
. 
<taxonomicName id="4C394D42C03F4606FD36F9B9FC303593" box="[713,963,1658,1680]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="38" pageNumber="39" phylum="Mollusca" rank="species" species="oxfordiana">
<emphasis id="B94DEAD3C03F4606FD36F9B9FC303593" box="[713,963,1658,1680]" italics="true" pageId="38" pageNumber="39">Helvetostrea oxfordiana</emphasis>
</taxonomicName>
. Figured bivalved type specimen of 
<taxonomicName id="4C394D42C03F4606FAA7F9B8FEF635AC" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="38" pageNumber="39" phylum="Mollusca" rank="species" species="oxfordiana">
<emphasis id="B94DEAD3C03F4606FAA7F9B8FEF635AC" italics="true" pageId="38" pageNumber="39">Ostrea oxfordiana</emphasis>
</taxonomicName>
, cf. Rollier 1917, pl. 40, fig. 1a–c, ETHZ Ve.S. 5146, Klein-Kembs (Kleinkems) near Lörrach (Baden- Württemberg), Germany (&quot;Terrain à Chailles&quot;, Lower Oxfordian, 
<taxonomicName id="4C394D42C03F4606FCBFF974FB9535CE" authority="Zone" authorityName="Zone" box="[832,1126,1719,1741]" class="Cephalopoda" family="Cardioceratidae" genus="Cardioceras" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ammonitida" pageId="38" pageNumber="39" phylum="Mollusca" rank="species" species="cordatum">
<emphasis id="B94DEAD3C03F4606FCBFF974FBD535CE" box="[832,1062,1719,1741]" italics="true" pageId="38" pageNumber="39">Cardioceras cordatum</emphasis>
Zone
</taxonomicName>
: 
<emphasis id="B94DEAD3C03F4606FB8DF974FB8C35CE" bold="true" box="[1138,1151,1719,1741]" pageId="38" pageNumber="39">7</emphasis>
, LV, interior; 
<emphasis id="B94DEAD3C03F4606FAEDF974FAEC35CE" bold="true" box="[1298,1311,1719,1741]" pageId="38" pageNumber="39">8</emphasis>
, LV ventral view; 
<emphasis id="B94DEAD3C03F4606FF2AF915FF1235EF" bold="true" box="[213,225,1750,1772]" pageId="38" pageNumber="39">9</emphasis>
, RV lateral. Scale bars 10 mm.
</paragraph>
</caption>
<paragraph id="8B8636C1C03F4606FF38F8D7FDC53477" blockId="38.[151,1436,1811,2016]" pageId="38" pageNumber="39">
In the study area, the species occurs as autochthonous element in horizons 
<date id="FF871001C03F4606FB9CF8D0FAEA342F" box="[1123,1305,1811,1836]" pageId="38" pageNumber="39" value="2600" valueMax="2900">2600 and 2900</date>
–3000, and allochthonous in horizons 300 (Banné Marls) (one small juvenile LV, VTT001-1169b, Pl. 11.3; Pl. 14.6), 2400, 2700 (Pl. 11.1d), and 3500 (
<figureCitation id="13022A44C03F4606FE2FF898FDE63477" box="[464,533,1883,1908]" captionStart="FIGURE 4" captionStartId="10.[151,250,1911,1933]" captionTargetBox="[192,1398,198,1883]" captionTargetId="figure@10.[187,1407,193,1889]" captionTargetPageId="10" captionText="FIGURE 4. Litho- and biostratigraphy of the observed parts of the Reuchenette Formation in the Ajoie, with distribution of oysters and characteristic fossils. A. Synthetic section. B. Detailed section of the Banné Member in Vâ Tche Tchâ (VTT), Lower Kimmeridgian. C. Detailed section of the upper part of the Courtedoux Member and “ Lower Virgula Marl ”; based on Tchâfouè (TCH) and Sur Combe Ronde (SCR), Upper Kimmeridgian (note separate bed numeration for VTT and SCR / TCH)." httpUri="https://zenodo.org/record/288038/files/figure.png" pageId="38" pageNumber="39">Fig. 4</figureCitation>
C).
</paragraph>
<paragraph id="8B8636C1C03F4606FF38F8BCFA6F34E3" blockId="38.[151,1436,1811,2016]" pageId="38" pageNumber="39">
Horizon 2600 is a mostly fine-grained, partially iron-oolitic limestone yielding numerous aggregates of 
<taxonomicName id="4C394D42C03F4606FA7EF842FF0734BF" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="38" pageNumber="39" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03F4606FA7EF842FF0734BF" italics="true" pageId="38" pageNumber="39">H. sequana</emphasis>
</taxonomicName>
LVs. Aggregates are reminiscent of ostreoliths described by 
<bibRefCitation id="EFA84B30C03F4606FC65F860FB8934BF" box="[922,1146,1955,1980]" pageId="38" pageNumber="39" refString="Wilson, M. A., Ozanne, C. R. &amp; Palmer, T. J. (1998) Origin and paleoecology of free-rolling oyster accumulations (ostreoliths) in the Middle Jurassic of southwestern Utah, USA. Palaios, 13 (1), 70 - 78. http: // dx. doi. org / 10.2307 / 3515282" type="journal article">
Wilson 
<emphasis id="B94DEAD3C03F4606FC0FF866FBD434BF" box="[1008,1063,1955,1980]" italics="true" pageId="38" pageNumber="39">et al.</emphasis>
(1998)
</bibRefCitation>
, with irregularly arranged specimens of different growth stages, growing in all directions which suggests several overturns (Pl. 4.8; Pl. 12.2).
</paragraph>
<paragraph id="8B8636C1C03E4607FF68FF54FC8D33F4" blockId="39.[151,1437,151,2013]" pageId="39" pageNumber="40">
Shell surfaces are covered by serpulids and small LVs of 
<taxonomicName id="4C394D42C03E4607FCD2FF5AFC2C33B3" box="[813,991,153,176]" class="Bivalvia" family="Gryphaeidae" genus="Nanogyra" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="nana">
<emphasis id="B94DEAD3C03E4607FCD2FF5AFC2C33B3" box="[813,991,153,176]" italics="true" pageId="39" pageNumber="40">Nanogyra nana</emphasis>
</taxonomicName>
and 
<emphasis id="B94DEAD3C03E4607FBE6FF54FB1533B3" box="[1049,1254,151,176]" italics="true" pageId="39" pageNumber="40">Gastrochaenolites</emphasis>
borings. In one case, 
<taxonomicName id="4C394D42C03E4607FF27FF7FFEAA33D6" box="[216,345,188,213]" class="Bivalvia" family="Mytilidae" genus="Lithophaga" kingdom="Animalia" order="Mytiloida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03E4607FF27FF7FFEAA33D6" box="[216,345,188,213]" italics="true" pageId="39" pageNumber="40">Lithophaga</emphasis>
</taxonomicName>
sp. is preserved in its borehole. The species co-occurs with stenohaline bivalves (
<taxonomicName id="4C394D42C03E4607FAE3FF7FFA6633D6" box="[1308,1429,188,213]" class="Bivalvia" family="Bakevelliidae" genus="Gervillella" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03E4607FAE3FF7FFA6633D6" box="[1308,1429,188,213]" italics="true" pageId="39" pageNumber="40">Gervillella</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C394D42C03E4607FF68FF23FE6033FB" authority="Myopholas" authorityName="Myopholas" box="[151,403,223,248]" class="Bivalvia" family="Laternulidae" genus="Cercomya" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pholadomyoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03E4607FF68FF23FE6033FB" box="[151,403,223,248]" italics="true" pageId="39" pageNumber="40">Cercomya, Myopholas</emphasis>
</taxonomicName>
, 
<taxonomicName id="4C394D42C03E4607FE5EFF1CFDDA33FB" box="[417,553,223,248]" class="Bivalvia" family="Arcticidae" genus="Anisocardia" higherTaxonomySource="CoL" kingdom="Animalia" order="Venerida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03E4607FE5EFF1CFDDA33FB" box="[417,553,223,248]" italics="true" pageId="39" pageNumber="40">Anisocardia</emphasis>
</taxonomicName>
) and the echinoid 
<taxonomicName id="4C394D42C03E4607FD06FF22FCA433FB" box="[761,855,225,248]" class="Echinoidea" family="Pygurids" genus="Pygurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" pageId="39" pageNumber="40" phylum="Echinodermata" rank="genus">
<emphasis id="B94DEAD3C03E4607FD06FF22FCA433FB" box="[761,855,225,248]" italics="true" pageId="39" pageNumber="40">Pygurus</emphasis>
</taxonomicName>
sp.
</paragraph>
<paragraph id="8B8636C1C03E4607FF38FEC7FCD732AF" blockId="39.[151,1437,151,2013]" pageId="39" pageNumber="40">
Horizon 2900 is a fossiliferous lithoclastic limestone with numerous LVs of 
<taxonomicName id="4C394D42C03E4607FBD6FEC7FB44321E" box="[1065,1207,260,285]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C03E4607FBD6FEC7FB44321E" box="[1065,1207,260,285]" italics="true" pageId="39" pageNumber="40">Helvetostrea</emphasis>
</taxonomicName>
; co-occurring fauna includes species of 
<emphasis id="B94DEAD3C03E4607FE87FEE4FBFE3243" box="[376,1037,295,320]" italics="true" pageId="39" pageNumber="40">
<taxonomicName id="4C394D42C03E4607FE87FEE4FE2E3243" box="[376,477,295,320]" class="Bivalvia" family="Pinnidae" genus="Trichites" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">Trichites</taxonomicName>
, 
<taxonomicName id="4C394D42C03E4607FE15FEE4FBFE3243" authority="Cucullaea, Myopholas, Placunopsis" authorityName="Cucullaea, Myopholas, Placunopsis" box="[490,1037,295,320]" class="Bivalvia" family="Bakevelliidae" genus="Gervillella" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">Gervillella, Cucullaea, Myopholas, Placunopsis</taxonomicName>
</emphasis>
, rare 
<taxonomicName id="4C394D42C03E4607FBADFEE4FB113243" box="[1106,1250,295,320]" class="Bivalvia" family="Trigoniidae" genus="Myophorella" higherTaxonomySource="GBIF" kingdom="Animalia" order="Trigonioida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03E4607FBADFEE4FB113243" box="[1106,1250,295,320]" italics="true" pageId="39" pageNumber="40">Myophorella</emphasis>
</taxonomicName>
(shells replaced by calcite), and recrystallized coral heads up to 
<quantity id="4CC19B24C03E4607FD3EFE8FFCFB3267" box="[705,776,332,356]" metricMagnitude="-1" metricUnit="m" metricValue="2.0" pageId="39" pageNumber="40" unit="cm" value="20.0">20 cm</quantity>
in size. This accumulation may represent a condensation horizon. It is truncated by a hardground (horizon 3000) penetrated by 
<emphasis id="B94DEAD3C03E4607FC35FEACFB64328B" box="[970,1175,367,392]" italics="true" pageId="39" pageNumber="40">Gastrochaenolites</emphasis>
sp. and overgrown by large, strongly abraded specimens of 
<taxonomicName id="4C394D42C03E4607FDC6FE57FCEE32AE" box="[569,797,404,429]" class="Bivalvia" family="Arctostreidae" genus="Circunula" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="cotyledon">
<emphasis id="B94DEAD3C03E4607FDC6FE57FCEE32AE" box="[569,797,404,429]" italics="true" pageId="39" pageNumber="40">Circunula cotyledon</emphasis>
</taxonomicName>
.
</paragraph>
<paragraph id="8B8636C1C03E4607FF38FE74FEC1311B" blockId="39.[151,1437,151,2013]" pageId="39" pageNumber="40">
The autochthonous or parautochthonous occurrences and associated faunas suggest that 
<taxonomicName id="4C394D42C03E4607FB56FE74FA6F32D3" box="[1193,1436,439,464]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03E4607FB56FE74FA6F32D3" box="[1193,1436,439,464]" italics="true" pageId="39" pageNumber="40">Helvetostrea sequana</emphasis>
</taxonomicName>
lived preferentially in shallow, fully marine environments where it formed buildups (
<typeStatus id="54828863C03E4607FBAAFE1FFB7432F7" box="[1109,1159,476,500]" pageId="39" pageNumber="40">type</typeStatus>
locality), small clusters, or ostreoliths.
</paragraph>
<paragraph id="8B8636C1C03E4607FF38FDE7FE9D30A7" blockId="39.[151,1437,151,2013]" pageId="39" pageNumber="40">
A similar setting was described by 
<bibRefCitation id="EFA84B30C03E4607FDA1FDE7FCB7313F" box="[606,836,548,573]" pageId="39" pageNumber="40" refString="Wilson, M. A., Ozanne, C. R. &amp; Palmer, T. J. (1998) Origin and paleoecology of free-rolling oyster accumulations (ostreoliths) in the Middle Jurassic of southwestern Utah, USA. Palaios, 13 (1), 70 - 78. http: // dx. doi. org / 10.2307 / 3515282" type="journal article">
Wilson 
<emphasis id="B94DEAD3C03E4607FD49FDE6FD02313E" box="[694,753,548,573]" italics="true" pageId="39" pageNumber="40">et al.</emphasis>
(1998)
</bibRefCitation>
for the American ostreoliths which were formed by 
<taxonomicName id="4C394D42C03E4607FF68FD84FEFB3163" box="[151,264,583,608]" class="Bivalvia" family="Arctostreidae" genus="Circunula" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreida" pageId="39" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C03E4607FF68FD84FEFB3163" box="[151,264,583,608]" italics="true" pageId="39" pageNumber="40">Circunula</emphasis>
</taxonomicName>
? 
<emphasis id="B94DEAD3C03E4607FEE4FD84FE683163" box="[283,411,583,608]" italics="true" pageId="39" pageNumber="40">strigilecula</emphasis>
reaching sizes of up to 
<quantity id="4CC19B24C03E4607FD59FD84FD03315C" box="[678,752,583,608]" metricMagnitude="-1" metricUnit="m" metricValue="5.0" pageId="39" pageNumber="40" unit="cm" value="50.0">50 cm</quantity>
. They occurred on hardgrounds and oolitic shoals but also in lagoonal facies (Middle Jurassic Carmel Formation, Utah, 
<collectingCountry id="F32E7651C03E4607FC9AFDAFFC513187" box="[869,930,620,644]" name="United States of America" pageId="39" pageNumber="40">USA</collectingCountry>
). 
<bibRefCitation id="EFA84B30C03E4607FC42FDAFFB483187" box="[957,1211,620,645]" pageId="39" pageNumber="40" refString="Fursich, F. T., Palmer, T. J. &amp; Goodyear, K. L. (1994) Growth and disintegration of bivalve-dominated patch reefs in the Upper Jurassic of southern England. Palaeontology, 37 (1), 131 - 171." type="journal article">
Fürsich 
<emphasis id="B94DEAD3C03E4607FBDEFDAEFB913186" box="[1057,1122,620,645]" italics="true" pageId="39" pageNumber="40">et al.</emphasis>
(1994)
</bibRefCitation>
reported reefoidal frameworks several meters wide and up to 
<quantity id="4CC19B24C03E4607FD53FD4CFD0031A4" box="[684,755,655,680]" metricMagnitude="0" metricUnit="m" metricValue="3.5" pageId="39" pageNumber="40" unit="m" value="3.5">3.5 m</quantity>
high constructed by 
<taxonomicName id="4C394D42C03E4607FC04FD52FB7231AB" box="[1019,1153,657,680]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="expansa">
<emphasis id="B94DEAD3C03E4607FC04FD52FB7231AB" box="[1019,1153,657,680]" italics="true" pageId="39" pageNumber="40">H. expansa</emphasis>
</taxonomicName>
, red algae (
<taxonomicName id="4C394D42C03E4607FAE4FD4CFA6F31AB" box="[1307,1436,655,680]" class="Gymnolaemata" family="Lekythoporidae" genus="Solenopora" higherTaxonomySource="GBIF" kingdom="Animalia" order="Cheilostomatida" pageId="39" pageNumber="40" phylum="Bryozoa" rank="genus">
<emphasis id="B94DEAD3C03E4607FAE4FD4CFA6F31AB" box="[1307,1436,655,680]" italics="true" pageId="39" pageNumber="40">Solenopora</emphasis>
</taxonomicName>
&quot; 
<emphasis id="B94DEAD3C03E4607FF5DFD77FED631CE" box="[162,293,692,717]" italics="true" pageId="39" pageNumber="40">portlandica</emphasis>
&quot;), the cyclostome bryozoan 
<emphasis id="B94DEAD3C03E4607FD81FD76FC4331CE" box="[638,944,692,717]" italics="true" pageId="39" pageNumber="40">Hyporosopora portlandica</emphasis>
(Gregory), and some cemented 
<taxonomicName id="4C394D42C03E4607FACAFD77FE8E31F3" authority="Cox, 1925" authorityName="Cox" authorityYear="1925" class="Bivalvia" family="Plicatulidae" genus="Plicatula" kingdom="Animalia" order="Pectinoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="damoni">
<emphasis id="B94DEAD3C03E4607FACAFD77FF1831F3" italics="true" pageId="39" pageNumber="40">Plicatula damoni</emphasis>
(
<bibRefCitation id="EFA84B30C03E4607FF05FD1BFE8631F3" author="Cox" box="[250,373,727,752]" pageId="39" pageNumber="40" refString="Cox, L. R. (1925) The fauna of the basal shell-bed of the Portland Stone, Isle of Portland. Proceedings of the Dorset Natural History and Antiquarian Field Club, 46, 113 - 172." type="journal article" year="1925">Cox, 1925</bibRefCitation>
)
</taxonomicName>
. 
<bibRefCitation id="EFA84B30C03E4607FE77FD14FD2631F3" author="Hoffmann" box="[392,725,727,752]" pageId="39" pageNumber="40" refString="Hoffmann, M. &amp; Krobicki, M. (1989) Oyster buildup within the disaerobic [sic] - facies mudstones (Middle Jurassic, Central Poland) - example of benthic island colonization. Annales Societatis Geologorum Poloniae, 59, 299 - 330." type="journal article" year="1989">Hoffmann &amp; Krobicki (1989)</bibRefCitation>
described a buildup of 
<quantity id="4CC19B24C03E4607FC21FD1BFBF931EC" box="[990,1034,728,752]" metricMagnitude="0" metricUnit="m" metricValue="2.0" pageId="39" pageNumber="40" unit="m" value="2.0">2 m</quantity>
lateral and 
<quantity id="4CC19B24C03E4607FB71FD1BFB3D31EC" box="[1166,1230,728,752]" metricMagnitude="-1" metricUnit="m" metricValue="8.0" pageId="39" pageNumber="40" unit="m" value="0.8">0.8 m</quantity>
vertical extension from the Middle Jurassic of 
<collectingCountry id="F32E7651C03E4607FE29FD3FFDD73016" box="[470,548,764,789]" name="Poland" pageId="39" pageNumber="40">Poland</collectingCountry>
constructed by 
<taxonomicName id="4C394D42C03E4607FD27FD3EFC1A3016" authority="Goldfuss" authorityName="Goldfuss" box="[728,1001,764,789]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="explanata">
<emphasis id="B94DEAD3C03E4607FD27FD3EFC9A3016" box="[728,873,764,789]" italics="true" pageId="39" pageNumber="40">H. explanata</emphasis>
(Goldfuss)
</taxonomicName>
surrounded by a dysaerobic mudstone facies. The buildup occurs in high energy sediments, deposited as an intercalation during a &quot;regressive&quot; phase, well documented by a shell bed with many clasts (including hiatus-concretions) with borings of 
<emphasis id="B94DEAD3C03E4607FB2FFC87FF0D3083" italics="true" pageId="39" pageNumber="40">Gastrochaenolites lapidicus</emphasis>
<bibRefCitation id="EFA84B30C03E4607FEFAFCA4FDFD3083" author="Kelly" box="[261,526,871,896]" pageId="39" pageNumber="40" refString="Kelly, S. R. A. &amp; Bromley, R. G. (1984) Ichnological nomenclature of clavate borings. Palaeontology, 27, 793 - 807." type="journal article" year="1984">Kelly &amp; Bromley, 1984</bibRefCitation>
and encrusting serpulids at the base of the buildup (
<bibRefCitation id="EFA84B30C03E4607FBA6FCA4FEAC30A7" author="Hoffmann" pageId="39" pageNumber="40" refString="Hoffmann, M. &amp; Krobicki, M. (1989) Oyster buildup within the disaerobic [sic] - facies mudstones (Middle Jurassic, Central Poland) - example of benthic island colonization. Annales Societatis Geologorum Poloniae, 59, 299 - 330." type="journal article" year="1989" yearSuffix="p">
Hoffmann &amp; Krobicki 1989, p. 308 
<emphasis id="B94DEAD3C03E4607FF22FC4FFF1830A6" bold="true" box="[221,235,908,933]" pageId="39" pageNumber="40">–</emphasis>
309, fig. 3
</bibRefCitation>
).
</paragraph>
<paragraph id="8B8636C1C03E4607FF38FC6CFE9530EE" blockId="39.[151,1437,151,2013]" pageId="39" pageNumber="40">
<emphasis id="B94DEAD3C03E4607FF38FC6CFE9F30CB" bold="true" box="[199,364,943,968]" pageId="39" pageNumber="40">Comparisons.</emphasis>
Species of 
<taxonomicName id="4C394D42C03E4607FDFEFC6CFD7C30CB" box="[513,655,943,968]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C03E4607FDFEFC6CFD7C30CB" box="[513,655,943,968]" italics="true" pageId="39" pageNumber="40">Helvetostrea</emphasis>
</taxonomicName>
<taxonomicNameLabel id="A27E57A8C03E4607FD63FC6CFD0230CB" box="[668,753,943,968]" pageId="39" pageNumber="40" rank="genus">
<emphasis id="B94DEAD3C03E4607FD63FC6CFD0230CB" bold="true" box="[668,753,943,968]" pageId="39" pageNumber="40">n. gen.</emphasis>
</taxonomicNameLabel>
and morphological similar forms are discussed below in alphabetical order.
</paragraph>
</subSubSection>
<subSubSection id="C323654AC03E4609FF38FC3BFB4D377E" lastPageId="41" lastPageNumber="42" pageId="39" pageNumber="40" type="reference_group">
<paragraph id="8B8636C1C03E4607FF38FC3BFC77360E" blockId="39.[151,1437,151,2013]" pageId="39" pageNumber="40">
&quot; 
<emphasis id="B94DEAD3C03E4607FF2DFC3BFEDA370C" box="[210,297,1016,1039]" italics="true" pageId="39" pageNumber="40">
<taxonomicName id="4C394D42C03E4607FF2DFC3BFED3370C" box="[210,288,1016,1039]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">Ostrea</taxonomicName>
&quot;
</emphasis>
<taxonomicName id="4C394D42C03E4607FECFFC3AFDD33713" authority="Rollier, 1917" authorityName="Rollier" authorityYear="1917" box="[304,544,1015,1040]" class="Bivalvia" family="Ostreidae" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="subTribe" subTribe="Caprina">
<emphasis id="B94DEAD3C03E4607FECFFC3AFE743713" box="[304,391,1017,1040]" italics="true" pageId="39" pageNumber="40">caprina</emphasis>
Rollier, 1917
</taxonomicName>
(pl. 39, fig. 2, and pl. 40, fig. 2a,b; pl. 39, fig. 2 is refigured on Fig. 16.1)—The species was first mentioned by 
<bibRefCitation id="EFA84B30C03E4607FE08FBDFFD043737" author="Moesch" box="[503,759,1052,1077]" pageId="39" pageNumber="40" refString="Moesch, C. (1867) Geologische Beschreibung des Aargauer-Jura und der nordlichen Gebietes des Kantons Zurich. Beitraege zur geologischen Karte der Schweiz, 4, i - xv, 319 pp." type="book" year="1867" yearSuffix="p">Moesch (1867: p. 148)</bibRefCitation>
from Gösgen near Olten (Aargau) and found in the &quot; 
<taxonomicName id="4C394D42C03E4607FAB3FBDEFA633737" box="[1356,1424,1053,1076]" class="Bivalvia" family="Mytilidae" genus="Perna" kingdom="Animalia" order="Mytiloida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03E4607FAB3FBDEFA633737" box="[1356,1424,1053,1076]" italics="true" pageId="39" pageNumber="40">Perna</emphasis>
</taxonomicName>
&quot; beds of the Geissberg Member (sensu 
<bibRefCitation id="EFA84B30C03E4607FD8BFBFCFD05375B" author="Gygi" box="[628,758,1087,1112]" pageId="39" pageNumber="40" refString="Gygi, R. A. (1969) Zur Stratigraphie der Oxford-Stufe (oberes Jura-System) der Nordschweiz und des suddeutschen Grenzgebietes. Beitrage zur Geologischen Karte der Schweiz, Neue Folge, 136, 1 - 123." type="journal article" year="1969">Gygi 1969</bibRefCitation>
), Upper Oxfordian (
<taxonomicName id="4C394D42C03E4607FC0DFBFCFB27375B" authority="Zone" authorityName="Zone" box="[1010,1236,1087,1112]" class="Cephalopoda" family="Aspidoceratidae" genus="Epipeltoceras" higherTaxonomySource="CoL" kingdom="Animalia" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="bimammatum">
<emphasis id="B94DEAD3C03E4607FC0DFBFCFB79375B" box="[1010,1162,1087,1112]" italics="true" pageId="39" pageNumber="40">bimammatum</emphasis>
Zone
</taxonomicName>
) of northeastern 
<collectingCountry id="F32E7651C03E4607FF68FBA7FED2377E" box="[151,289,1124,1149]" name="Switzerland" pageId="39" pageNumber="40">Switzerland</collectingCountry>
. However, Rollier (1917, p. 562) was the first to provide a valid description. The 
<typeStatus id="54828863C03E4607FB4AFBA6FB16377E" box="[1205,1253,1125,1149]" pageId="39" pageNumber="40">type</typeStatus>
series consisted of one bivalved specimen with both shells isolated and an unknown number of other specimens mentioned in the text from different locations, but only the figured bivalved specimen (ETHZ Ve.S. 4563) of Rollier (1917: pl. 39, fig. 2, pl. 40, fig 2a,b) is still preserved in the collections of the ETH Zürich. It is here chosen as 
<typeStatus id="54828863C03E4607FAEBFB0CFA8837EB" box="[1300,1403,1231,1256]" pageId="39" pageNumber="40" type="lectotype">lectotype</typeStatus>
of 
<taxonomicName id="4C394D42C03E4607FF68FB37FDDC360F" authority="Rollier, 1917" authorityName="Rollier" authorityYear="1917" box="[151,559,1268,1293]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="caprina">
<emphasis id="B94DEAD3C03E4607FF68FB37FE70360F" box="[151,387,1268,1293]" italics="true" pageId="39" pageNumber="40">Helvetostrea caprina</emphasis>
(Rollier, 1917)
</taxonomicName>
and figured on Fig. 16.1, 2–6.
</paragraph>
<paragraph id="8B8636C1C03E4607FF38FAD4FB3A369E" blockId="39.[151,1437,151,2013]" pageId="39" pageNumber="40">
This species is less inflated than 
<taxonomicName id="4C394D42C03E4607FDC3FADAFD4F3633" box="[572,700,1305,1328]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03E4607FDC3FADAFD4F3633" box="[572,700,1305,1328]" italics="true" pageId="39" pageNumber="40">H. sequana</emphasis>
</taxonomicName>
, more subrectangular and lacks an umbonal cavity. Shell habitus and ligament area of the 
<typeStatus id="54828863C03E4607FE42FAFFFDD73656" box="[445,548,1340,1365]" pageId="39" pageNumber="40" type="lectotype">lectotype</typeStatus>
LV (Fig. 16.1–2) mimic a RV, but the adductor position and presence of an attachment area confirm that it is a LV. The comparison of the original figures of Rollier (1917) with photographs of the 
<typeStatus id="54828863C03E4607FF21FA47FEB7369E" box="[222,324,1412,1437]" pageId="39" pageNumber="40" type="lectotype">lectotype</typeStatus>
reveals a mismatch of the real proportions and hinge morphology (Fig. 16.1–6).
</paragraph>
<paragraph id="8B8636C1C03E4607FF38FA6BFD7B359B" blockId="39.[151,1437,151,2013]" pageId="39" pageNumber="40">
&quot; 
<taxonomicName id="4C394D42C03E4607FF2DFA6BFEEE36BC" box="[210,285,1448,1471]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03E4607FF2DFA6BFEEE36BC" box="[210,285,1448,1471]" italics="true" pageId="39" pageNumber="40">Ostrea</emphasis>
</taxonomicName>
&quot; 
<taxonomicName id="4C394D42C03E4607FED0FA6AFDA136C3" authority="J. Sowerby, 1819" authorityName="J. Sowerby" authorityYear="1819" box="[303,594,1447,1472]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="expansa">
<emphasis id="B94DEAD3C03E4607FED0FA6AFE7836C3" box="[303,395,1449,1472]" italics="true" pageId="39" pageNumber="40">expansa</emphasis>
J. Sowerby, 1819
</taxonomicName>
(p. 65, pl. 238, fig. 1)—This species was first described from the Tithonian Tisbury Limestone Member of the Portland Stone Formation (
<taxonomicName id="4C394D42C03E4607FCA2FA0EFB6236E7" authority="Zone" authorityName="Zone" box="[861,1169,1484,1508]" class="Cephalopoda" family="Perisphinctidae" genus="Titanites" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ammonitida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="anguiformis">
<emphasis id="B94DEAD3C03E4607FCA2FA0EFBBD36E7" box="[861,1102,1484,1508]" italics="true" pageId="39" pageNumber="40">Titanites anguiformis</emphasis>
Zone
</taxonomicName>
) in Wiltshire, 
<collectingCountry id="F32E7651C03E4607FAC8FA0FFA6B36E6" box="[1335,1432,1484,1509]" name="United Kingdom" pageId="39" pageNumber="40">England</collectingCountry>
. Sowerby’s figured specimen, a silicified RV, was assumed to be lost (
<bibRefCitation id="EFA84B30C03E4607FC39FA33FB6B350B" author="Cox" box="[966,1176,1520,1544]" pageId="39" pageNumber="40" refString="Cox, L. R. (1929) A synopsis of the Lamellibranchia and Gastropoda of the Portland Beds of England. Part I - Lamellibranchia. Proceedings of the Dorset Natural History and Antiquarian Field Club, 50, 131 - 202." type="journal article" year="1929" yearSuffix="p">Cox 1929, p. 147</bibRefCitation>
). However, 
<bibRefCitation id="EFA84B30C03E4607FAD9FA33FEC6352F" author="Spamer" pageId="39" pageNumber="40" refString="Spamer, E. E. &amp; Bogan, A. E. (1989) Recovery of the Etheldred Benett Collection of fossils mostly from Jurassic-Cretaceous strata of Wiltshire, England, analysis of the taxonomic nomenclature of Benett (1831), and notes and figures of type specimens contained in the collection. Proceedings of the Academy of Natural Sciences of Philadelphia, 141, 115 - 180." type="journal article" year="1989">Spamer &amp; Bogan (1989)</bibRefCitation>
may have found the original or a 
<typeStatus id="54828863C03E4607FD30F9D6FCD5352E" box="[719,806,1557,1581]" pageId="39" pageNumber="40" type="syntype">syntype</typeStatus>
and potential 
<typeStatus id="54828863C03E4607FC2FF9D7FBC4352E" box="[976,1079,1556,1581]" pageId="39" pageNumber="40" type="lectotype">lectotype</typeStatus>
in the Benett-collection at the Academy of Natural Sciences of Philadelphia (
<collectingCountry id="F32E7651C03E4607FD58F9FBFD113553" box="[679,738,1592,1616]" name="United States of America" pageId="39" pageNumber="40">USA</collectingCountry>
) which is listed as &quot; 
<taxonomicName id="4C394D42C03E4607FC39F9FBFAC93553" authority="J. Sowerby 1819" authorityName="J. Sowerby" authorityYear="1819" box="[966,1338,1591,1616]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="expansa">
<emphasis id="B94DEAD3C03E4607FC39F9FBFB873553" box="[966,1140,1592,1616]" italics="true" pageId="39" pageNumber="40">Ostrea expansa</emphasis>
J. Sowerby 1819
</taxonomicName>
, pl. 238, top figure [1]; 
<typeStatus id="54828863C03E4607FEC0F99FFE6E3577" box="[319,413,1628,1652]" pageId="39" pageNumber="40" type="syntype">syntype</typeStatus>
(?), ANSP 56158 (B.C. 287; Benett's[?] no. 196); Fonthill, Wiltshire&quot;. The Fonthill Abbey Wood is situated 
<quantity id="4CC19B24C03E4607FEA7F943FE62359B" box="[344,401,1663,1688]" metricMagnitude="3" metricUnit="m" metricValue="3.0" pageId="39" pageNumber="40" unit="km" value="3.0">3 km</quantity>
northwest of Tisbury.
</paragraph>
<paragraph id="8B8636C1C03E4607FF38F967FA6F34DE" blockId="39.[151,1437,151,2013]" pageId="39" pageNumber="40">
Sowerby’s figure is somewhat reminiscent of the flat, broadly crescentic shape of 
<taxonomicName id="4C394D42C03E4607FBA5F967FB2E35BE" box="[1114,1245,1700,1725]" class="Bivalvia" family="Gryphaeidae" genus="Deltoideum" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03E4607FBA5F967FB2E35BE" box="[1114,1245,1700,1725]" italics="true" pageId="39" pageNumber="40">Deltoideum</emphasis>
</taxonomicName>
(Rollier 1917, p. 566: 
<taxonomicName id="4C394D42C03E4607FF2FF904FE4635E3" box="[208,437,1735,1760]" class="Bivalvia" family="Gryphaeidae" genus="Deltoideum" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="expansa">
<emphasis id="B94DEAD3C03E4607FF2FF904FE4635E3" box="[208,437,1735,1760]" italics="true" pageId="39" pageNumber="40">Deltoideum expansa</emphasis>
</taxonomicName>
). However, the overall shape is spatulate without a concave posterodorsal margin typical of 
<taxonomicName id="4C394D42C03E4607FF47F92FFEC83406" box="[184,315,1772,1797]" class="Bivalvia" family="Gryphaeidae" genus="Deltoideum" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03E4607FF47F92FFEC83406" box="[184,315,1772,1797]" italics="true" pageId="39" pageNumber="40">Deltoideum</emphasis>
</taxonomicName>
. Furthermore, the shell is thicker and larger, and the PAM more centrally situated. Despite these differences, 
<bibRefCitation id="EFA84B30C03E4607FEDCF8D3FE0E342B" author="Cox" box="[291,509,1807,1832]" pageId="39" pageNumber="40" refString="Cox, L. R. (1925) The fauna of the basal shell-bed of the Portland Stone, Isle of Portland. Proceedings of the Dorset Natural History and Antiquarian Field Club, 46, 113 - 172." type="journal article" year="1925" yearSuffix="p">Cox (1925, p. 130)</bibRefCitation>
assumed a transition between 
<taxonomicName id="4C394D42C03E4607FCA0F8CCFB3A342B" authority="Smith, 1817" authorityName="Smith" authorityYear="1817" box="[863,1225,1807,1832]" class="Bivalvia" family="Gryphaeidae" genus="Deltoideum" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="delta">
<emphasis id="B94DEAD3C03E4607FCA0F8CCFBD1342B" box="[863,1058,1807,1832]" italics="true" pageId="39" pageNumber="40">Deltoideum delta</emphasis>
(Smith, 1817)
</taxonomicName>
[= 
<taxonomicName id="4C394D42C03E4607FB0BF8D3FEB1344E" authority="J. Sowerby, 1816" authorityName="J. Sowerby" authorityYear="1816" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="deltoidea">
<emphasis id="B94DEAD3C03E4607FB0BF8D3FA72342B" box="[1268,1409,1807,1832]" italics="true" pageId="39" pageNumber="40">
<collectingCountry id="F32E7651C03E4607FB0BF8D3FAF83424" box="[1268,1291,1808,1831]" name="Iceland" pageId="39" pageNumber="40">O</collectingCountry>
. deltoidea
</emphasis>
J. Sowerby, 1816
</taxonomicName>
, non Lamarck 1806, = 
<taxonomicName id="4C394D42C03E4607FDB4F8F6FC4D344E" authority="Bronn, 1836" authorityName="Bronn" authorityYear="1836" box="[587,958,1844,1869]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="sowerbyana">
<emphasis id="B94DEAD3C03E4607FDB4F8F6FCD6344E" box="[587,805,1844,1869]" italics="true" pageId="39" pageNumber="40">Ostrea sowerbyana</emphasis>
Bronn, 1836
</taxonomicName>
, replacement name for the former] and 
<taxonomicName id="4C394D42C03E4607FA7EF8F6FF003473" class="Bivalvia" family="Gryphaeidae" genus="Deltoideum" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="expansa">
<emphasis id="B94DEAD3C03E4607FA7EF8F6FF003473" italics="true" pageId="39" pageNumber="40">
<collectingCountry id="F32E7651C03E4607FA7EF8F6FA6B344F" box="[1409,1432,1845,1868]" name="Iceland" pageId="39" pageNumber="40">O</collectingCountry>
. expansa
</emphasis>
</taxonomicName>
. 
<bibRefCitation id="EFA84B30C03E4607FEFDF894FDB03473" author="Pugaczewska" box="[258,579,1879,1904]" pageId="39" pageNumber="40" refString="Pugaczewska, H. (1971) Jurassic Ostreidae of Poland. Acta Palaeontologica Polonica, 16 (3), 195 - 311." type="journal article" year="1971" yearSuffix="p">Pugaczewska (1971, p. 269)</bibRefCitation>
, 
<bibRefCitation id="EFA84B30C03E4607FDAFF894FCC43473" box="[592,823,1879,1904]" pageId="39" pageNumber="40" refString="Fursich, F. T., Palmer, T. J. &amp; Goodyear, K. L. (1994) Growth and disintegration of bivalve-dominated patch reefs in the Upper Jurassic of southern England. Palaeontology, 37 (1), 131 - 171." type="journal article">
Fürsich 
<emphasis id="B94DEAD3C03E4607FD53F89AFD2E3473" box="[684,733,1879,1904]" italics="true" pageId="39" pageNumber="40">et al</emphasis>
. (1994)
</bibRefCitation>
and 
<bibRefCitation id="EFA84B30C03E4607FC8FF894FB423473" author="Fursich" box="[880,1201,1879,1904]" pageId="39" pageNumber="40" refString="Fursich, F. T. &amp; Hautmann, M. (2005) Bivalve reefs from the upper Triassic of Iran. Annali dell' Universita di Ferrara, sezione Museologia Scientifica e Naturalistica. Special volume in honour of Carmela Loriga, 13 - 23." type="book chapter" year="2005">Fürsich &amp; Hautmann (2005)</bibRefCitation>
assigned the species to 
<taxonomicName id="4C394D42C03E4607FF47F8BEFEE73497" box="[184,276,1917,1940]" class="Bivalvia" family="Gryphaeidae" genus="Liostrea" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="39" pageNumber="40" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C03E4607FF47F8BEFEE73497" box="[184,276,1917,1940]" italics="true" pageId="39" pageNumber="40">Liostrea</emphasis>
</taxonomicName>
. However, the spatulate shell shape and presence of large shell chambers below the ligament area suggest that 
<taxonomicName id="4C394D42C03E4607FEDDF862FE6C34BB" box="[290,415,1953,1976]" class="Bivalvia" family="Gryphaeidae" genus="Deltoideum" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="expansa">
<emphasis id="B94DEAD3C03E4607FEDDF862FE6C34BB" box="[290,415,1953,1976]" italics="true" pageId="39" pageNumber="40">
<collectingCountry id="F32E7651C03E4607FEDDF862FECA34BB" box="[290,313,1953,1976]" name="Iceland" pageId="39" pageNumber="40">O</collectingCountry>
. expansa
</emphasis>
</taxonomicName>
belongs to 
<taxonomicName id="4C394D42C03E4607FDDFF863FD5D34BA" box="[544,686,1952,1977]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C03E4607FDDFF863FD5D34BA" box="[544,686,1952,1977]" italics="true" pageId="39" pageNumber="40">Helvetostrea</emphasis>
</taxonomicName>
. The species differs from 
<taxonomicName id="4C394D42C03E4607FC2EF862FBBC34BB" box="[977,1103,1953,1976]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="39" pageNumber="40" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C03E4607FC2EF862FBBC34BB" box="[977,1103,1953,1976]" italics="true" pageId="39" pageNumber="40">H. sequana</emphasis>
</taxonomicName>
by a broader resilifer, slender bourrelets, a larger PAM, a convex RV and a small umbonal cavity (
<bibRefCitation id="EFA84B30C03E4607FC3DF807FB5634DF" author="Fursich" box="[962,1189,1988,2013]" pageId="39" pageNumber="40" refString="Fursich, F. T., Palmer, T. J. &amp; Goodyear, K. L. (1994) Growth and disintegration of bivalve-dominated patch reefs in the Upper Jurassic of southern England. Palaeontology, 37 (1), 131 - 171." type="journal article" year="1994">
Fürsich 
<emphasis id="B94DEAD3C03E4607FBDCF806FBA434DE" box="[1059,1111,1988,2013]" italics="true" pageId="39" pageNumber="40">et al</emphasis>
. 1994
</bibRefCitation>
, p. 138, 141, fig. 5).
</paragraph>
<paragraph id="8B8636C1C0314608FF68FF54FE32321F" blockId="40.[151,1437,151,2013]" pageId="40" pageNumber="41">
Remarkable is the distribution of both species in rocks representing shallow marine environments that are overlain by paleosoils with dinosaur track sites of the Lower Purbeck Formation in 
<collectingCountry id="F32E7651C0314608FC0FFF7FFBBE33D6" box="[1008,1101,188,213]" name="United Kingdom" pageId="40" pageNumber="41">England</collectingCountry>
(
<bibRefCitation id="EFA84B30C0314608FBA2FF7FFAAE33D7" author="Ensom" box="[1117,1373,188,213]" pageId="40" pageNumber="41" refString="Ensom, P. C. &amp; Delair, J. B. (2007) Dinosaur tracks from the lower Purbeck strata of Portland, Dorset, southern England. Geoscience in south-west England, 11, 309 - 325." type="journal article" year="2007">Ensom &amp; Delair 2007</bibRefCitation>
) and, respectively, the Kimmeridgian track-bearing horizons (tidal-flat laminites) of the Reuchenette Formation in 
<collectingCountry id="F32E7651C0314608FF68FEC7FEEE321E" box="[151,285,260,285]" name="Switzerland" pageId="40" pageNumber="41">Switzerland</collectingCountry>
(Marty 2008).
</paragraph>
<paragraph id="8B8636C1C0314608FF38FEEBFAAB32AE" blockId="40.[151,1437,151,2013]" pageId="40" pageNumber="41">
<emphasis id="B94DEAD3C0314608FF38FEEBFEDA323C" box="[199,297,296,319]" italics="true" pageId="40" pageNumber="41">
&quot; 
<taxonomicName id="4C394D42C0314608FF2FFEEBFED3323C" box="[208,288,296,319]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">Ostrea</taxonomicName>
&quot;
</emphasis>
<taxonomicName id="4C394D42C0314608FECEFEE4FDA73243" authority="Goldfuss, 1833" authorityName="Goldfuss" authorityYear="1833" box="[305,596,295,320]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="explanata">
<emphasis id="B94DEAD3C0314608FECEFEE4FE533243" box="[305,416,295,320]" italics="true" pageId="40" pageNumber="41">explanata</emphasis>
Goldfuss, 1833
</taxonomicName>
(b) (p. 22, pl. 80, fig. 5)—This is the oldest species that could be attributed to 
<taxonomicName id="4C394D42C0314608FF4BFE8FFEB13266" box="[180,322,332,357]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C0314608FF4BFE8FFEB13266" box="[180,322,332,357]" italics="true" pageId="40" pageNumber="41">Helvetostrea</emphasis>
</taxonomicName>
. Goldfuss described it from a Middle Jurassic Oolite (Bajocian?) of Southern 
<collectingCountry id="F32E7651C0314608FB43FE8FFAD73267" box="[1212,1316,332,356]" name="Germany" pageId="40" pageNumber="41">Germany</collectingCountry>
(region of Bayreuth and Württemberg, 
<typeStatus id="54828863C0314608FE19FEB3FDE5328B" box="[486,534,368,392]" pageId="40" pageNumber="41">type</typeStatus>
locality not specified). In Europe, it ranges from the Bajocian to the Early Callovian in 
<collectingCountry id="F32E7651C0314608FED8FE57FE7432AE" box="[295,391,404,429]" name="United Kingdom" pageId="40" pageNumber="41">England</collectingCountry>
, 
<collectingCountry id="F32E7651C0314608FE6CFE56FE2C32AF" box="[403,479,405,428]" name="France" pageId="40" pageNumber="41">France</collectingCountry>
and 
<collectingCountry id="F32E7651C0314608FDE9FE57FD9732AE" box="[534,612,404,429]" name="Poland" pageId="40" pageNumber="41">Poland</collectingCountry>
(
<bibRefCitation id="EFA84B30C0314608FD8DFE57FC4532AF" author="Hoffmann" box="[626,950,404,429]" pageId="40" pageNumber="41" refString="Hoffmann, M. &amp; Krobicki, M. (1989) Oyster buildup within the disaerobic [sic] - facies mudstones (Middle Jurassic, Central Poland) - example of benthic island colonization. Annales Societatis Geologorum Poloniae, 59, 299 - 330." type="journal article" year="1989">Hoffmann &amp; Krobicki, 1989</bibRefCitation>
, p. 308; 
<bibRefCitation id="EFA84B30C0314608FBE9FE57FB0632AF" author="Pugaczewska" box="[1046,1269,404,429]" pageId="40" pageNumber="41" refString="Pugaczewska, H. (1971) Jurassic Ostreidae of Poland. Acta Palaeontologica Polonica, 16 (3), 195 - 311." type="journal article" year="1971">Pugaczewska, 1971</bibRefCitation>
, p. 245).
</paragraph>
<paragraph id="8B8636C1C0314608FF38FE74FADD31AB" blockId="40.[151,1437,151,2013]" pageId="40" pageNumber="41">
The species is usually determined as 
<taxonomicName id="4C394D42C0314608FD59FE7AFCF132D3" box="[678,770,441,464]" class="Bivalvia" family="Gryphaeidae" genus="Liostrea" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C0314608FD59FE7AFCF132D3" box="[678,770,441,464]" italics="true" pageId="40" pageNumber="41">Liostrea</emphasis>
</taxonomicName>
(e.g. 
<bibRefCitation id="EFA84B30C0314608FCA7FE74FBCA32D3" author="Pugaczewska" box="[856,1081,439,464]" pageId="40" pageNumber="41" refString="Pugaczewska, H. (1971) Jurassic Ostreidae of Poland. Acta Palaeontologica Polonica, 16 (3), 195 - 311." type="journal article" year="1971">Pugaczewska 1971</bibRefCitation>
) coinciding with its ancient synonymization with 
<taxonomicName id="4C394D42C0314608FE68FE1EFC9D32F7" authority="Schlotheim, 1820" authorityName="Schlotheim" authorityYear="1820" box="[407,878,476,501]" class="Bivalvia" family="Gryphaeidae" genus="Liostrea" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="eduliformis">
<emphasis id="B94DEAD3C0314608FE68FE1EFD7332F6" box="[407,640,476,501]" italics="true" pageId="40" pageNumber="41">Liostrea eduliformis</emphasis>
(
<bibRefCitation id="EFA84B30C0314608FD69FE1FFC9632F7" author="Schlotheim" box="[662,869,476,501]" pageId="40" pageNumber="41" refString="Schlotheim, E. F. von (1820) Die Petrefactenkunde. Becker, Gotha, lxii + 437 pp." type="book" year="1820">Schlotheim, 1820</bibRefCitation>
)
</taxonomicName>
by 
<bibRefCitation id="EFA84B30C0314608FC5AFE1EFBA532F6" author="Roemer" box="[933,1110,476,501]" pageId="40" pageNumber="41" refString="Roemer, F. A. (1835 - 1839) Die Versteinerungen des norddeutschen Oolithen-Gebirges. Hahn, Hannover, part 1, i - vi, 1 - 74, pls. 1 - 12 (1835); part 2, 75 - 134, pls. 13 - 16 (1836 a), part 3 (new title), 65 - 68 (new), 135 - 218, pls. 1 - 12 (new) (1836 b); Ein Nachtrag (Addendum), i - iv, 1 - 59, pls. 17 - 20, Tab. A (geologic profiles) (1839)." type="journal article" year="1835">Roemer (1835)</bibRefCitation>
and 
<bibRefCitation id="EFA84B30C0314608FB65FE1FFAA732F7" author="Schlippe" box="[1178,1364,476,501]" pageId="40" pageNumber="41" refString="Schlippe, A. O. (1888) Die Fauna des Bathonien im Oberrheinischen Tieflande. Abhandlungen zur Geologischen Special-Karte von Elsaß-Lothringen, 4 (4), 1 - 266." type="journal article" year="1888">Schlippe (1888)</bibRefCitation>
(here considered as a 
<taxonomicName id="4C394D42C0314608FEB7FDC2FE37311B" box="[328,452,513,536]" class="Bivalvia" family="Gryphaeidae" genus="Pernostrea" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C0314608FEB7FDC2FE37311B" box="[328,452,513,536]" italics="true" pageId="40" pageNumber="41">Pernostrea</emphasis>
</taxonomicName>
). Specimens figured by Goldfuss (1833)(b) show a broad but short ligament area which is also more reminiscent of 
<taxonomicName id="4C394D42C0314608FE34FDE6FDB5313F" box="[459,582,549,572]" class="Bivalvia" family="Gryphaeidae" genus="Pernostrea" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C0314608FE34FDE6FDB5313F" box="[459,582,549,572]" italics="true" pageId="40" pageNumber="41">Pernostrea</emphasis>
</taxonomicName>
, whereas a right valve figured by 
<bibRefCitation id="EFA84B30C0314608FC3DFDE7FB50313F" author="Pugaczewska" box="[962,1187,548,573]" pageId="40" pageNumber="41" refString="Pugaczewska, H. (1971) Jurassic Ostreidae of Poland. Acta Palaeontologica Polonica, 16 (3), 195 - 311." type="journal article" year="1971">Pugaczewska (1971</bibRefCitation>
, pl. 9, figs. 5a,b) has a remarkably undulated hinge line and ligament similar to 
<taxonomicName id="4C394D42C0314608FCE5FD84FC5B3163" box="[794,936,583,608]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C0314608FCE5FD84FC5B3163" box="[794,936,583,608]" italics="true" pageId="40" pageNumber="41">Helvetostrea</emphasis>
</taxonomicName>
. Hence, “ 
<collectingCountry id="F32E7651C0314608FBE6FD8BFBDE315C" box="[1049,1069,584,607]" name="Iceland" pageId="40" pageNumber="41">
<emphasis id="B94DEAD3C0314608FBE6FD8BFBDE315C" box="[1049,1069,584,607]" italics="true" pageId="40" pageNumber="41">O</emphasis>
</collectingCountry>
.” 
<taxonomicName id="4C394D42C0314608FBB6FD84FF123187" authority="Pugaczewska (1971)" authorityName="Pugaczewska" authorityYear="1971" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="explanata">
<emphasis id="B94DEAD3C0314608FBB6FD84FB4B3163" box="[1097,1208,583,608]" italics="true" pageId="40" pageNumber="41">explanata</emphasis>
sensu 
<bibRefCitation id="EFA84B30C0314608FAFAFD84FF123187" author="Pugaczewska" pageId="40" pageNumber="41" refString="Pugaczewska, H. (1971) Jurassic Ostreidae of Poland. Acta Palaeontologica Polonica, 16 (3), 195 - 311." type="journal article" year="1971">Pugaczewska (1971)</bibRefCitation>
</taxonomicName>
may belong to 
<taxonomicName id="4C394D42C0314608FE5BFDAFFDC13186" box="[420,562,620,645]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C0314608FE5BFDAFFDC13186" box="[420,562,620,645]" italics="true" pageId="40" pageNumber="41">Helvetostrea</emphasis>
</taxonomicName>
. However, it differs from 
<taxonomicName id="4C394D42C0314608FC8EFDAEFC063187" box="[881,1013,621,644]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C0314608FC8EFDAEFC063187" box="[881,1013,621,644]" italics="true" pageId="40" pageNumber="41">H. sequana</emphasis>
</taxonomicName>
by its larger size (in height), more rectangular and less inflated shape, and lack of an umbonal cavity (
<bibRefCitation id="EFA84B30C0314608FC78FD4CFAD231AB" author="Hoffmann" box="[903,1313,655,680]" pageId="40" pageNumber="41" refString="Hoffmann, M. &amp; Krobicki, M. (1989) Oyster buildup within the disaerobic [sic] - facies mudstones (Middle Jurassic, Central Poland) - example of benthic island colonization. Annales Societatis Geologorum Poloniae, 59, 299 - 330." type="journal article" year="1989" yearSuffix="p">Hoffmann &amp; Krobicki, 1989, p. 308</bibRefCitation>
).
</paragraph>
<paragraph id="8B8636C1C0314608FF38FD77FE3130CB" blockId="40.[151,1437,151,2013]" pageId="40" pageNumber="41">
&quot; 
<emphasis id="B94DEAD3C0314608FF2DFD76FEDA31CF" box="[210,297,693,716]" italics="true" pageId="40" pageNumber="41">
<taxonomicName id="4C394D42C0314608FF2DFD76FED331CF" box="[210,288,693,716]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">Ostrea</taxonomicName>
&quot;
</emphasis>
<taxonomicName id="4C394D42C0314608FECDFD77FDBB31CE" authority="Rollier, 1917" authorityName="Rollier" authorityYear="1917" box="[306,584,692,717]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="oxfordiana">
<emphasis id="B94DEAD3C0314608FECDFD77FE5F31CE" box="[306,428,692,717]" italics="true" pageId="40" pageNumber="41">oxfordiana</emphasis>
Rollier, 1917
</taxonomicName>
—This rare species was originally described from the &quot;Terrain à Chailles&quot; facies (
<taxonomicName id="4C394D42C0314608FF11FD14FE8831F3" ID-CoL="7PCG3" box="[238,379,727,752]" class="Bivalvia" family="Pholadomyidae" genus="Pholadomya" kingdom="Animalia" order="Anomalodesmata" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C0314608FF11FD14FE8831F3" box="[238,379,727,752]" italics="true" pageId="40" pageNumber="41">Pholadomya</emphasis>
</taxonomicName>
marls, Early Oxfordian, 
<emphasis id="B94DEAD3C0314608FD53FD14FCFE31F3" box="[684,781,727,752]" italics="true" pageId="40" pageNumber="41">cordatus</emphasis>
Zone) of Klein-Kembs (Kleinkems) from the &quot;Isteiner Klotz&quot;, a prominent ridge some kilometres north of Lörrach (Baden-Württemberg, 
<collectingCountry id="F32E7651C0314608FBCDFD3FFB533017" box="[1074,1184,764,788]" name="Germany" pageId="40" pageNumber="41">Germany</collectingCountry>
). The figured 
<typeStatus id="54828863C0314608FAC5FD3FFA6F3016" box="[1338,1436,764,789]" pageId="40" pageNumber="41" type="holotype">holotype</typeStatus>
(fixed by monotypy, ICZN 73.1.2.; see also ICZN 73.1.5. which implies that a 
<typeStatus id="54828863C0314608FBCFFCDCFB61303B" box="[1072,1170,799,824]" pageId="40" pageNumber="41" type="holotype">holotype</typeStatus>
can consist of a set of disarticulated components) consisted of a rather well preserved LV and a corresponding but damaged RV (Rollier 1917, pl. 40, figs. 1a–c, here refigured in Fig. 16.7–9). It belonged to the Casimir Moesch collection held at the ETH in Zürich (Ve. S. 5146, according to Rollier 1917); unfortunately, its current whereabouts is unknown (Pika- Biolzi, pers. comm. 2011).
</paragraph>
<paragraph id="8B8636C1C0314608FF38FC17FDB63736" blockId="40.[151,1437,151,2013]" pageId="40" pageNumber="41">
The species could be a 
<taxonomicName id="4C394D42C0314608FE37FC17FDA530EE" box="[456,598,980,1005]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C0314608FE37FC17FDA530EE" box="[456,598,980,1005]" italics="true" pageId="40" pageNumber="41">Helvetostrea</emphasis>
</taxonomicName>
that differs from 
<taxonomicName id="4C394D42C0314608FCE6FC16FC6B30EF" box="[793,920,981,1004]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C0314608FCE6FC16FC6B30EF" box="[793,920,981,1004]" italics="true" pageId="40" pageNumber="41">H. sequana</emphasis>
</taxonomicName>
by having a more pronounced umbo, possibly due to a smaller attachment area, shorter ligament area, lesser convexity of the LV, more prolonged commissural shelf, and a shallower umbonal cavity.
</paragraph>
<paragraph id="8B8636C1C0314608FF38FB83FD3F37EB" blockId="40.[151,1437,151,2013]" pageId="40" pageNumber="41">
In contrast, 
<taxonomicName id="4C394D42C0314608FEA3FB82FB3D375B" authority="Pugaczewska" authorityName="Pugaczewska" authorityYear="1971" box="[348,1230,1087,1112]" class="Bivalvia" family="Gryphaeidae" genus="Liostrea" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="oxfordiana">
<emphasis id="B94DEAD3C0314608FEA3FB82FDB2375B" box="[348,577,1087,1112]" italics="true" pageId="40" pageNumber="41">Liostrea oxfordiana</emphasis>
sensu 
<bibRefCitation id="EFA84B30C0314608FD62FBFCFB3D375B" author="Pugaczewska" box="[669,1230,1087,1112]" pageId="40" pageNumber="41" refString="Pugaczewska, H. (1971) Jurassic Ostreidae of Poland. Acta Palaeontologica Polonica, 16 (3), 195 - 311." type="journal article" year="1971" yearSuffix="p">
Pugaczewska (1971, p. 249, pl. 13, figs. 5 
<emphasis id="B94DEAD3C0314608FB57FBFCFB45375B" bold="true" box="[1192,1206,1087,1112]" pageId="40" pageNumber="41">–</emphasis>
9)
</bibRefCitation>
</taxonomicName>
from the Lower Kimmeridgian of West Pomerania (
<collectingCountry id="F32E7651C0314608FDD5FBA7FD88377E" box="[554,635,1124,1149]" name="Poland" pageId="40" pageNumber="41">Poland</collectingCountry>
) as well as 
<taxonomicName id="4C394D42C0314608FCFBFBA6FB41377F" authority="Arkell, 1927" authorityName="Arkell" authorityYear="1927" box="[772,1202,1124,1149]" class="Bivalvia" family="Gryphaeidae" genus="Liostrea" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="quadrangularis">
<emphasis id="B94DEAD3C0314608FCFBFBA6FBE4377E" box="[772,1047,1124,1149]" italics="true" pageId="40" pageNumber="41">Liostrea quadrangularis</emphasis>
Arkell, 1927
</taxonomicName>
, sensu 
<bibRefCitation id="EFA84B30C0314608FAFAFBA7FE1A37A3" author="Pugaczewska" pageId="40" pageNumber="41" refString="Pugaczewska, H. (1971) Jurassic Ostreidae of Poland. Acta Palaeontologica Polonica, 16 (3), 195 - 311." type="journal article" year="1971" yearSuffix="p">Pugaczewska (1971, p. 250, pl. 8, figs. 1–4)</bibRefCitation>
are more likely phenotypes of 
<taxonomicName id="4C394D42C0314608FCB7FB4AFBC037A3" box="[840,1075,1159,1184]" class="Bivalvia" family="Gryphaeidae" genus="Liostrea" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="polymorpha">
<emphasis id="B94DEAD3C0314608FCB7FB4AFBC037A3" box="[840,1075,1159,1184]" italics="true" pageId="40" pageNumber="41">Liostrea polymorpha</emphasis>
</taxonomicName>
(Münster in Goldfuss, 1833)(b) (
<bibRefCitation id="EFA84B30C0314608FF61FB6FFDB937C7" author="Pugaczewska" box="[158,586,1196,1221]" pageId="40" pageNumber="41" refString="Pugaczewska, H. (1971) Jurassic Ostreidae of Poland. Acta Palaeontologica Polonica, 16 (3), 195 - 311." type="journal article" year="1971">
Pugaczewska 1971, pl. 19, figs. 5 
<emphasis id="B94DEAD3C0314608FDD2FB6FFDC837C6" bold="true" box="[557,571,1196,1221]" pageId="40" pageNumber="41">–</emphasis>
8
</bibRefCitation>
). All these species differ from 
<taxonomicName id="4C394D42C0314608FC3FFB6EFBB737C7" box="[960,1092,1197,1220]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C0314608FC3FFB6EFBB737C7" box="[960,1092,1197,1220]" italics="true" pageId="40" pageNumber="41">H. sequana</emphasis>
</taxonomicName>
by a markedly opisthogyrate ligament area, and a weakly sickle-shaped 
<taxonomicName id="4C394D42C0314608FD88FB0CFD3B37EB" box="[631,712,1231,1256]" class="Bivalvia" family="Ostreidae" genus="Actinostreon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="outline">outline</taxonomicName>
.
</paragraph>
<paragraph id="8B8636C1C0314608FF38FB36FE2D35DC" blockId="40.[151,1437,151,2013]" pageId="40" pageNumber="41">
<emphasis id="B94DEAD3C0314608FF38FB36FEDA360F" box="[199,297,1269,1292]" italics="true" pageId="40" pageNumber="41">
&quot; 
<taxonomicName id="4C394D42C0314608FF2FFB36FED3360F" box="[208,288,1269,1292]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">Ostrea</taxonomicName>
&quot;
</emphasis>
<taxonomicName id="4C394D42C0314608FECDFB36FDA7360E" authority="Etallon, 1862" authorityName="Etallon" authorityYear="1862" box="[306,596,1268,1293]" class="Bivalvia" family="Gryphaeidae" genus="Gryphaea" higherTaxonomySource="CoL" kingdom="Animalia" order="Ostreida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="ermontiana">
<emphasis id="B94DEAD3C0314608FECDFB36FE40360F" box="[306,435,1269,1292]" italics="true" pageId="40" pageNumber="41">ermontiana</emphasis>
<bibRefCitation id="EFA84B30C0314608FE44FB37FDA7360E" author="Etallon" box="[443,596,1268,1293]" pageId="40" pageNumber="41" refString="Etallon, A. (1862) Etudes paleontologique sur le Haut-Jura. Memoires de la Societe d'Emulation du Departement du Doubs, Serie 3., 6, 53 - 260." type="journal article" year="1862">Etallon, 1862</bibRefCitation>
</taxonomicName>
(in 
<bibRefCitation id="EFA84B30C0314608FD7BFB37FC45360E" author="Thurmann" box="[644,950,1268,1293]" pageId="40" pageNumber="41" refString="Thurmann, J. &amp; Etallon, A. (1861 - 1864), Lethea Bruntrutana ou Etudes paleontologiques et stratigraphiques sur le Jura Bernois et en particulier les environs de Porrentruy. Denkschriften der Schweizerischen Naturforschenden Gesellschaft, 18 - 20, 1 - 146 (1861), 147 - 354 (1862), 355 - 500 (1864)." type="journal article" year="1861">
Thurmann &amp; Etallon, 
<date id="FF871001C0314608FC80FB37FC45360E" box="[895,950,1268,1293]" pageId="40" pageNumber="41" value="1861" valueMax="1864">1861</date>
</bibRefCitation>
–1864, p. 270, pl. 38, fig. 6)—The species was erected as a substitute for 
<taxonomicName id="4C394D42C0314608FDE8FADBFC4F3633" authority="Contejean, 1859" authorityName="Contejean" authorityYear="1859" box="[535,956,1303,1328]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="gryphoides">
<emphasis id="B94DEAD3C0314608FDE8FADBFD1E3633" box="[535,749,1303,1328]" italics="true" pageId="40" pageNumber="41">Ostrea gryphoides</emphasis>
<bibRefCitation id="EFA84B30C0314608FD05FAD4FC4F3633" author="Contejean" box="[762,956,1303,1328]" pageId="40" pageNumber="41" refString="Contejean, C. H. (1859) Etude de l'etage Kimmeridien dans les environs de Montbeliard et dans le Jura, la France et l'Angleterre. Memoires de la Societe d'Emulation du Doubs, Year 1858, 1 - 352." type="journal article" year="1859">Contejean, 1859</bibRefCitation>
</taxonomicName>
, which is a junior homonym of 
<taxonomicName id="4C394D42C0314608FAAEFADBFEE73656" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="gryphoides">
<emphasis id="B94DEAD3C0314608FAAEFADBFEE73656" italics="true" pageId="40" pageNumber="41">Ostrea gryphoides</emphasis>
</taxonomicName>
von Zieten, 1830, and 
<taxonomicName id="4C394D42C0314608FDECFAFEFC5C3657" authority="Schlotheim, 1813" authorityName="Schlotheim" authorityYear="1813" box="[531,943,1340,1365]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="gryphoides">
<emphasis id="B94DEAD3C0314608FDECFAFEFD123656" box="[531,737,1340,1365]" italics="true" pageId="40" pageNumber="41">Ostrea gryphoides</emphasis>
<bibRefCitation id="EFA84B30C0314608FD18FAFFFC5C3657" author="Schlotheim" box="[743,943,1340,1365]" pageId="40" pageNumber="41" refString="Schlotheim, E. F. von (1813) Beitrage zur Naturgeschichte der Versteinerungen in geognostischer Hinsicht. Leonhard's Taschenbuch der Mineralogie, 7, 1 - 134." type="journal article" year="1813">Schlotheim, 1813</bibRefCitation>
</taxonomicName>
. Contejean’s (1859, p. 320, pl. 25, figs. 1–5) material came from the Upper Oxfordian “Calcaires à 
<taxonomicName id="4C394D42C0314608FD04FA9CFCAD367B" box="[763,862,1375,1400]" class="Bivalvia" family="Cardiidae" genus="Cardium" kingdom="Animalia" order="Veneroida" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C0314608FD04FA9CFCAD367B" box="[763,862,1375,1400]" italics="true" pageId="40" pageNumber="41">Cardium</emphasis>
</taxonomicName>
” and Lower Kimmeridgian “Marnes et Calcaires à ptérocères” of Montbéliard (
<collectingCountry id="F32E7651C0314608FE28FA47FDD4369F" box="[471,551,1412,1436]" name="France" pageId="40" pageNumber="41">France</collectingCountry>
) (housed at the Musée Cuvier in Montbéliard, MC 27E125 = LV in 
<bibRefCitation id="EFA84B30C0314608FAD5FA47FF2136C3" author="Contejean" pageId="40" pageNumber="41" refString="Contejean, C. H. (1859) Etude de l'etage Kimmeridien dans les environs de Montbeliard et dans le Jura, la France et l'Angleterre. Memoires de la Societe d'Emulation du Doubs, Year 1858, 1 - 352." type="journal article" year="1859">Contejean 1859</bibRefCitation>
, pl. 25, figs. 1, 3; MC 27E126 = LV, pl. 25, figs. 2, 4; MC27E127 = LV, pl. 25, fig. 5). However, all specimens are exfoliated internal moulds with few shell remains. Because the specimens are, at face value, indeterminable, and because there is no other material mentioned, the figured LV of 
<taxonomicName id="4C394D42C0314608FC6BFA33FBC4350B" box="[916,1079,1520,1544]" class="Bivalvia" family="Gryphaeidae" genus="Gryphaea" higherTaxonomySource="CoL" kingdom="Animalia" order="Ostreida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="ermontiana">
<emphasis id="B94DEAD3C0314608FC6BFA33FBC4350B" box="[916,1079,1520,1544]" italics="true" pageId="40" pageNumber="41">
<collectingCountry id="F32E7651C0314608FC6BFA33FC583504" box="[916,939,1520,1543]" name="Iceland" pageId="40" pageNumber="41">O</collectingCountry>
. ermontiana
</emphasis>
</taxonomicName>
is here considered as 
<typeStatus id="54828863C0314608FAD1FA2CFA6B350B" box="[1326,1432,1519,1544]" pageId="40" pageNumber="41" type="lectotype">lectotype</typeStatus>
. The specimen was found in the &quot;Hypostrombien inférieur&quot; (= Nautilid Beds, Reuchenette Formation, Lower Kimmeridgian) of Fahy near Porrentruy, but neither the 
<typeStatus id="54828863C0314608FCE1F9F4FC733553" box="[798,896,1591,1616]" pageId="40" pageNumber="41" type="holotype">holotype</typeStatus>
nor any other material potentially representing this species was found in the Jurassica-Museum (MJSN) Porrentruy. One additional complete and well-preserved specimen, determined as 
<taxonomicName id="4C394D42C0314608FE4BF943FD17359B" authority="Etallon" authorityName="Etallon" box="[436,740,1663,1688]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="ermontiana">
<emphasis id="B94DEAD3C0314608FE4BF943FD7B359B" box="[436,648,1664,1688]" italics="true" pageId="40" pageNumber="41">Ostrea ermontiana</emphasis>
Etallon
</taxonomicName>
, was found in the collection Scheurer (MC-27E122) from the “Calcaire à 
<taxonomicName id="4C394D42C0314608FEE4F967FE9435BE" box="[283,359,1700,1725]" class="Bivalvia" family="Cardiidae" genus="Corbis" higherTaxonomySource="CoL" kingdom="Animalia" order="Cardiida" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C0314608FEE4F967FE9435BE" box="[283,359,1700,1725]" italics="true" pageId="40" pageNumber="41">Corbis</emphasis>
</taxonomicName>
” (
<emphasis id="B94DEAD3C0314608FE7BF967FE0735BE" box="[388,500,1700,1725]" italics="true" pageId="40" pageNumber="41">cymodoce</emphasis>
Zone) at Baume in Audincourt (
<collectingCountry id="F32E7651C0314608FC9DF967FC4635BF" box="[866,949,1700,1724]" name="France" pageId="40" pageNumber="41">France</collectingCountry>
). It also contains a note by Scheurer that 
<taxonomicName id="4C394D42C0314608FA7EF966FEE735E3" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="gryphoides">
<emphasis id="B94DEAD3C0314608FA7EF966FEE735E3" italics="true" pageId="40" pageNumber="41">
<collectingCountry id="F32E7651C0314608FA7EF966FA6B35BF" box="[1409,1432,1701,1724]" name="Iceland" pageId="40" pageNumber="41">O</collectingCountry>
. gryphoides
</emphasis>
</taxonomicName>
is 
<taxonomicName id="4C394D42C0314608FECBF90BFE2435E3" box="[308,471,1736,1760]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="ermontiana">
<emphasis id="B94DEAD3C0314608FECBF90BFE2435E3" box="[308,471,1736,1760]" italics="true" pageId="40" pageNumber="41">
<collectingCountry id="F32E7651C0314608FECBF90BFEB835DC" box="[308,331,1736,1759]" name="Iceland" pageId="40" pageNumber="41">O</collectingCountry>
. ermontiana
</emphasis>
</taxonomicName>
.
</paragraph>
<paragraph id="8B8636C1C0314608FF38F92FFE5E3473" blockId="40.[151,1437,151,2013]" pageId="40" pageNumber="41">
The figured 
<typeStatus id="54828863C0314608FEAEF92FFE4B3406" box="[337,440,1772,1797]" pageId="40" pageNumber="41" type="lectotype">lectotype</typeStatus>
in Thurmann &amp; 
<bibRefCitation id="EFA84B30C0314608FD8CF92FFCE53406" box="[627,790,1772,1797]" pageId="40" pageNumber="41" refString="Etallon, A. (1862) Etudes paleontologique sur le Haut-Jura. Memoires de la Societe d'Emulation du Departement du Doubs, Serie 3., 6, 53 - 260." type="journal article">Etallon (1862)</bibRefCitation>
is a small LV gryphaeoid shell (L 
<quantity id="4CC19B24C0314608FB66F92FFB1B3407" box="[1177,1256,1772,1797]" metricMagnitude="-2" metricUnit="m" metricValue="5.5" pageId="40" pageNumber="41" unit="cm" value="5.5">5.5 cm</quantity>
, H 
<quantity id="4CC19B24C0314608FAF1F92FFAAF3407" box="[1294,1372,1772,1797]" metricMagnitude="-2" metricUnit="m" metricValue="3.5" pageId="40" pageNumber="41" unit="cm" value="3.5">3.5 cm</quantity>
) with an orthogyrate ligament area, which appears as drawing similar to 
<taxonomicName id="4C394D42C0314608FC71F8D2FBFD342B" box="[910,1038,1809,1832]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C0314608FC71F8D2FBFD342B" box="[910,1038,1809,1832]" italics="true" pageId="40" pageNumber="41">H. sequana</emphasis>
</taxonomicName>
. After comparison of the available material an assignment of 
<taxonomicName id="4C394D42C0314608FE42F8F6FD92344F" box="[445,609,1845,1868]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="ermontiana">
<emphasis id="B94DEAD3C0314608FE42F8F6FD92344F" box="[445,609,1845,1868]" italics="true" pageId="40" pageNumber="41">
<collectingCountry id="F32E7651C0314608FE42F8F6FE27344F" box="[445,468,1845,1868]" name="Iceland" pageId="40" pageNumber="41">O</collectingCountry>
. ermontiana
</emphasis>
</taxonomicName>
to 
<taxonomicName id="4C394D42C0314608FD7BF8F7FCE1344E" box="[644,786,1844,1869]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C0314608FD7BF8F7FCE1344E" box="[644,786,1844,1869]" italics="true" pageId="40" pageNumber="41">Helvetostrea</emphasis>
</taxonomicName>
can be excluded and the species can certainly be assigned to 
<taxonomicName id="4C394D42C0314608FF4BF894FE543473" authority="Bilobissa" authorityName="Bilobissa" box="[180,423,1879,1904]" class="Bivalvia" family="Gryphaeidae" genus="Gryphaea" higherTaxonomySource="CoL" kingdom="Animalia" order="Ostreida" pageId="40" pageNumber="41" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C0314608FF4BF894FED73473" box="[180,292,1879,1904]" italics="true" pageId="40" pageNumber="41">Gryphaea</emphasis>
(
<emphasis id="B94DEAD3C0314608FECBF894FE6F3473" box="[308,412,1879,1904]" italics="true" pageId="40" pageNumber="41">Bilobissa</emphasis>
)
</taxonomicName>
.
</paragraph>
<paragraph id="8B8636C1C0314609FF38F8BFFCD8321F" blockId="40.[151,1437,151,2013]" lastBlockId="41.[151,1436,151,1149]" lastPageId="41" lastPageNumber="42" pageId="40" pageNumber="41">
Differences to 
<taxonomicName id="4C394D42C0314608FE93F8BEFE183497" box="[364,491,1917,1940]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C0314608FE93F8BEFE183497" box="[364,491,1917,1940]" italics="true" pageId="40" pageNumber="41">H. sequana</emphasis>
</taxonomicName>
are the presence of a deep radial posterior sulcus (Thurmann &amp; 
<bibRefCitation id="EFA84B30C0314608FB47F8BFFAB83496" author="Etallon" box="[1208,1355,1916,1941]" pageId="40" pageNumber="41" refString="Etallon, A. (1862) Etudes paleontologique sur le Haut-Jura. Memoires de la Societe d'Emulation du Departement du Doubs, Serie 3., 6, 53 - 260." type="journal article" year="1862">Etallon 1862</bibRefCitation>
, pl. 38, fig. 6, posterior view), which is characteristic of 
<emphasis id="B94DEAD3C0314608FD47F863FCD334BA" box="[696,800,1952,1977]" italics="true" pageId="40" pageNumber="41">Bilobissa</emphasis>
, the thin and not chambered shell, the nearly smooth LV and a RV with antimarginal threads (preserved on specimen MC-27E122). The relationship of 
<taxonomicName id="4C394D42C0314609FAD3F807FE6F33B3" class="Bivalvia" family="Gryphaeidae" genus="Gryphaea" higherTaxonomySource="CoL" kingdom="Animalia" lastPageId="41" lastPageNumber="42" order="Ostreida" pageId="40" pageNumber="41" phylum="Mollusca" rank="species" species="ermontiana" subGenus="Bilobissa">
<emphasis id="B94DEAD3C0314608FAD3F807FA6F34DE" box="[1324,1436,1988,2013]" italics="true" pageId="40" pageNumber="41">Gryphaea</emphasis>
(
<emphasis id="B94DEAD3C0304609FF5FFF54FEFB33B3" box="[160,264,151,176]" italics="true" pageId="41" pageNumber="42">Bilobissa</emphasis>
) 
<emphasis id="B94DEAD3C0304609FEE4FF5AFE6F33B3" box="[283,412,153,176]" italics="true" pageId="41" pageNumber="42">ermontiana</emphasis>
</taxonomicName>
(Etallon in Thurmann &amp; 
<bibRefCitation id="EFA84B30C0304609FD3DFF54FCA833B3" author="Etallon" box="[706,859,151,176]" pageId="41" pageNumber="42" refString="Etallon, A. (1862) Etudes paleontologique sur le Haut-Jura. Memoires de la Societe d'Emulation du Departement du Doubs, Serie 3., 6, 53 - 260." type="journal article" year="1862">Etallon, 1862</bibRefCitation>
) to 
<taxonomicName id="4C394D42C0304609FC74FF54FA9D33B3" authority="J. Sowerby, 1816" authorityName="J. Sowerby" authorityYear="1816" box="[907,1390,151,176]" class="Bivalvia" family="Gryphaeidae" genus="Gryphaea" higherTaxonomySource="CoL" kingdom="Animalia" order="Ostreida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="dilatata" subGenus="Bilobissa">
<emphasis id="B94DEAD3C0304609FC74FF54FC0833B3" box="[907,1019,151,176]" italics="true" pageId="41" pageNumber="42">Gryphaea</emphasis>
(
<emphasis id="B94DEAD3C0304609FBF2FF5AFBD633B3" box="[1037,1061,153,176]" italics="true" pageId="41" pageNumber="42">B.</emphasis>
) 
<emphasis id="B94DEAD3C0304609FBC8FF54FB7D33B3" box="[1079,1166,151,176]" italics="true" pageId="41" pageNumber="42">dilatata</emphasis>
(J. Sowerby, 1816)
</taxonomicName>
has not been investigated, but the occurrence of this species in the Early Kimmeridgian (
<emphasis id="B94DEAD3C0304609FB7CFF7FFB0033D6" box="[1155,1267,188,213]" italics="true" pageId="41" pageNumber="42">cymodoce</emphasis>
Zones) of the Reuchenette Formation in 
<collectingCountry id="F32E7651C0304609FE40FF1CFDB633FB" box="[447,581,223,248]" name="Switzerland" pageId="41" pageNumber="42">Switzerland</collectingCountry>
and nearby 
<collectingCountry id="F32E7651C0304609FD32FF23FCEA33F4" box="[717,793,224,247]" name="France" pageId="41" pageNumber="42">France</collectingCountry>
represents one of the last records of 
<taxonomicName id="4C394D42C0304609FB4EFF1CFAD233FB" box="[1201,1313,223,248]" class="Bivalvia" family="Gryphaeidae" genus="Gryphaea" higherTaxonomySource="CoL" kingdom="Animalia" order="Ostreida" pageId="41" pageNumber="42" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C0304609FB4EFF1CFAD233FB" box="[1201,1313,223,248]" italics="true" pageId="41" pageNumber="42">Gryphaea</emphasis>
</taxonomicName>
in Europe, beside its record from 
<collectingCountry id="F32E7651C0304609FE6CFEC7FE12321E" box="[403,481,260,285]" name="Poland" pageId="41" pageNumber="42">Poland</collectingCountry>
(
<bibRefCitation id="EFA84B30C0304609FE10FEC7FCEC321F" author="Pugaczewska" box="[495,799,260,285]" pageId="41" pageNumber="42" refString="Pugaczewska, H. (1971) Jurassic Ostreidae of Poland. Acta Palaeontologica Polonica, 16 (3), 195 - 311." type="journal article" year="1971" yearSuffix="p">Pugaczewska 1971, p. 277</bibRefCitation>
).
</paragraph>
<paragraph id="8B8636C1C0304609FF38FEEBFC783186" blockId="41.[151,1436,151,1149]" pageId="41" pageNumber="42">
“ 
<taxonomicName id="4C394D42C0304609FF2CFEEBFEAA323C" box="[211,345,296,319]" class="Bivalvia" family="Ostreidae" genus="Crassostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C0304609FF2CFEEBFEAA323C" box="[211,345,296,319]" italics="true" pageId="41" pageNumber="42">Crassostrea</emphasis>
</taxonomicName>
” 
<taxonomicName id="4C394D42C0304609FE92FEEAFD263243" authority="Komatsu et al., 2002" authorityName="Komatsu et al." authorityYear="2002" box="[365,725,295,320]" class="Bivalvia" family="Ostreidae" genus="Crassostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="tetoriensis">
<emphasis id="B94DEAD3C0304609FE92FEEAFE113243" box="[365,482,297,320]" italics="true" pageId="41" pageNumber="42">tetoriensis</emphasis>
<bibRefCitation id="EFA84B30C0304609FE16FEEBFD263243" author="Komatsu" box="[489,725,295,320]" pageId="41" pageNumber="42" refString="Komatsu, T., Chinzei, K., Zakhera, M. S. &amp; Matsuoka, H. (2002) Jurassic soft - bottom oyster Crassostrea from Japan. Palaeontology, 45 (6), 1037 - 1048. http: // dx. doi. org / 10.1111 / 1475 - 4983.00274" type="journal article" year="2002">
Komatsu 
<emphasis id="B94DEAD3C0304609FDA9FEEAFD7C3243" box="[598,655,295,320]" italics="true" pageId="41" pageNumber="42">et al.</emphasis>
, 2002
</bibRefCitation>
</taxonomicName>
—This oyster is only known from the Middle Jurassic of 
<collectingCountry id="F32E7651C0304609FAA3FEEBFA6F323C" box="[1372,1436,296,319]" name="Japan" pageId="41" pageNumber="42">Japan</collectingCountry>
(Bathonian, Ushimaru Formation, Tetori Group) (see 
<bibRefCitation id="EFA84B30C0304609FCEFFE8FFC6A3267" author="Fujita" box="[784,921,332,357]" pageId="41" pageNumber="42" refString="Fujita, M. (2003) Geological age and correlation of the vertebrate-bearing horizons in the Tetori Group. Memoir of the Fukui Prefectural Dinosaur Museum, 2, 3 - 14." type="journal article" year="2003">Fujita 2003</bibRefCitation>
, fig. 2, for stratigraphy). Like 
<taxonomicName id="4C394D42C0304609FAF1FE8FFA6F3266" box="[1294,1436,332,357]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C0304609FAF1FE8FFA6F3266" box="[1294,1436,332,357]" italics="true" pageId="41" pageNumber="42">Helvetostrea</emphasis>
</taxonomicName>
species, “ 
<emphasis id="B94DEAD3C0304609FEFDFEB3FEE63284" box="[258,277,368,391]" italics="true" pageId="41" pageNumber="42">C</emphasis>
.” 
<taxonomicName id="4C394D42C0304609FED0FEB2FD7C328B" authority="Komatsu et al. 2002" authorityName="Komatsu et al." authorityYear="2002" box="[303,655,367,392]" class="Bivalvia" family="Ostreidae" genus="Crassostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="tetoriensis">
<emphasis id="B94DEAD3C0304609FED0FEB2FE57328B" box="[303,420,369,392]" italics="true" pageId="41" pageNumber="42">tetoriensis</emphasis>
<bibRefCitation id="EFA84B30C0304609FE55FEB3FD7C328B" author="Komatsu" box="[426,655,367,392]" pageId="41" pageNumber="42" refString="Komatsu, T., Chinzei, K., Zakhera, M. S. &amp; Matsuoka, H. (2002) Jurassic soft - bottom oyster Crassostrea from Japan. Palaeontology, 45 (6), 1037 - 1048. http: // dx. doi. org / 10.1111 / 1475 - 4983.00274" type="journal article" year="2002">
Komatsu 
<emphasis id="B94DEAD3C0304609FDE9FEB2FDBD328B" box="[534,590,367,392]" italics="true" pageId="41" pageNumber="42">et al.</emphasis>
2002
</bibRefCitation>
</taxonomicName>
, p. 1043, figs. 3, 5–7 developed numerous chambers in the LV, a deep umbonal cavity, an elongated ligament area, lack of chomata, and inequivalve shells without radial ornament. It also occurs below non-marine deposits with dinosaur bones and tracks (compare paleoecology of 
<taxonomicName id="4C394D42C0304609FB21FE7AFAAD32D3" box="[1246,1374,441,464]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C0304609FB21FE7AFAAD32D3" box="[1246,1374,441,464]" italics="true" pageId="41" pageNumber="42">H. sequana</emphasis>
</taxonomicName>
). The species differs from 
<taxonomicName id="4C394D42C0304609FE52FE1FFD6C32F7" box="[429,671,476,501]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C0304609FE52FE1FFD6C32F7" box="[429,671,476,501]" italics="true" pageId="41" pageNumber="42">Helvetostrea sequana</emphasis>
</taxonomicName>
by its very high, elongate-spatulate 
<taxonomicName id="4C394D42C0304609FBCBFE1FFB7132F6" box="[1076,1154,476,501]" class="Bivalvia" family="Ostreidae" genus="Actinostreon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="outline">outline</taxonomicName>
(
<taxonomicName id="4C394D42C0304609FB6EFE1EFAD432F7" box="[1169,1319,477,500]" class="Bivalvia" family="Ostreidae" genus="Crassostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="tetoriensis">
<emphasis id="B94DEAD3C0304609FB6EFE1EFAD432F7" box="[1169,1319,477,500]" italics="true" pageId="41" pageNumber="42">C. tetoriensis</emphasis>
</taxonomicName>
: H/L ratio 2.9–3.7; 
<taxonomicName id="4C394D42C0304609FF02FDC2FE73311B" box="[253,384,513,536]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="sequana">
<emphasis id="B94DEAD3C0304609FF02FDC2FE73311B" box="[253,384,513,536]" italics="true" pageId="41" pageNumber="42">H. sequana</emphasis>
</taxonomicName>
H/L 1.23–1.86), thin, mainly simple compact foliated shells with small chambers, usually filled with chalky deposits, a small reniform PAM not supported by a ventral shell swelling (buttress), narrow bourrelets and tiny attachment area (
<bibRefCitation id="EFA84B30C0304609FDC1FD8BFCDD3163" author="Komatsu" box="[574,814,583,608]" pageId="41" pageNumber="42" refString="Komatsu, T., Chinzei, K., Zakhera, M. S. &amp; Matsuoka, H. (2002) Jurassic soft - bottom oyster Crassostrea from Japan. Palaeontology, 45 (6), 1037 - 1048. http: // dx. doi. org / 10.1111 / 1475 - 4983.00274" type="journal article" year="2002">
Komatsu 
<emphasis id="B94DEAD3C0304609FD51FD8AFD193163" box="[686,746,583,608]" italics="true" pageId="41" pageNumber="42">et al.</emphasis>
2002
</bibRefCitation>
, p. 1043). In addition, the species was most probably adapted to euryhaline, muddy, intertidal, soft bottom environments.
</paragraph>
<paragraph id="8B8636C1C0304609FF30FD53FEBD31F3" blockId="41.[151,1436,151,1149]" pageId="41" pageNumber="42">
“ 
<taxonomicName id="4C394D42C0304609FF23FD53FED431A4" box="[220,295,656,679]" class="Bivalvia" family="Ostreidae" genus="Ostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="genus">
<emphasis id="B94DEAD3C0304609FF23FD53FED431A4" box="[220,295,656,679]" italics="true" pageId="41" pageNumber="42">Ostrea</emphasis>
</taxonomicName>
” 
<taxonomicName id="4C394D42C0304609FEC3FD4CFDA531AB" authority="Forbes, 1851" authorityName="Forbes" authorityYear="1851" box="[316,598,655,680]" class="Bivalvia" family="Gryphaeidae" genus="Praeexogyra" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="hebridica">
<emphasis id="B94DEAD3C0304609FEC3FD4CFE5B31AB" box="[316,424,655,680]" italics="true" pageId="41" pageNumber="42">hebridica</emphasis>
(
<bibRefCitation id="EFA84B30C0304609FE48FD4CFDBE31AB" author="Forbes" box="[439,589,655,680]" pageId="41" pageNumber="42" refString="Forbes, E. (1851) On the Estuary Beds and the Oxford Clay at Loch Staffin in Skye. Quarterly Journal of the Geological Society, 7, 104 - 113. http: // dx. doi. org / 10.1144 / GSL. JGS. 1851.007.01 - 02.24" type="journal article" year="1851">Forbes, 1851</bibRefCitation>
)
</taxonomicName>
<emphasis id="B94DEAD3C0304609FDA9FD52FD9C31AB" box="[598,623,657,680]" italics="true" pageId="41" pageNumber="42">—</emphasis>
The species was originally described from the upper part of the Middle Jurassic (Bathonian) “Great Estuarine Series” of Loch Staffin, Isle of Skye, Inner 
<collectingCountry id="F32E7651C0304609FBB0FD77FB4731CE" box="[1103,1204,692,717]" name="United Kingdom" pageId="41" pageNumber="42">Hebrides</collectingCountry>
of 
<collectingCountry id="F32E7651C0304609FB20FD77FAB231CE" box="[1247,1345,692,717]" name="United Kingdom" pageId="41" pageNumber="42">Scotland</collectingCountry>
(
<bibRefCitation id="EFA84B30C0304609FAADFD77FEB231F3" author="Arkell" pageId="41" pageNumber="42" refString="Arkell, W. J. (1934) The oysters of the Fuller's Earth and the evolution and nomenclature of the Upper Jurassic Catinulas and Gryphaeas. Proceedings of the Cotteswold Naturalists' Field Club, 25, 21 - 68." type="journal article" year="1934" yearSuffix="p">Arkell 1934, p. 11–12</bibRefCitation>
).
</paragraph>
<paragraph id="8B8636C1C0304609FF38FD3EFC5130A6" blockId="41.[151,1436,151,1149]" pageId="41" pageNumber="42">
Most of the previous authors, including 
<bibRefCitation id="EFA84B30C0304609FD78FD3FFC183017" author="Hudson" box="[647,1003,764,789]" pageId="41" pageNumber="42" refString="Hudson, J. D. &amp; Palmer, T. J. (1976) A euryhaline oyster from the Middle Jurassic and the origin of true oysters. Palaeontology, 19 (1), 79 - 93." type="journal article" year="1976" yearSuffix="p">Hudson &amp; Palmer (1976, p. 87)</bibRefCitation>
, accepted a close relationship between “ 
<collectingCountry id="F32E7651C0304609FF5CFCE3FF443034" box="[163,183,800,823]" name="Iceland" pageId="41" pageNumber="42">
<emphasis id="B94DEAD3C0304609FF5CFCE3FF443034" box="[163,183,800,823]" italics="true" pageId="41" pageNumber="42">O</emphasis>
</collectingCountry>
.” 
<taxonomicName id="4C394D42C0304609FF2AFCDCFEB2303B" box="[213,321,799,824]" class="Bivalvia" family="Gryphaeidae" genus="Praeexogyra" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="hebridica">
<emphasis id="B94DEAD3C0304609FF2AFCDCFEB2303B" box="[213,321,799,824]" italics="true" pageId="41" pageNumber="42">hebridica</emphasis>
</taxonomicName>
and 
<taxonomicName id="4C394D42C0304609FE83FCE2FD7E303B" box="[380,653,801,824]" class="Bivalvia" family="Gryphaeidae" genus="Praeexogyra" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="acuminata">
<emphasis id="B94DEAD3C0304609FE83FCE2FD7E303B" box="[380,653,801,824]" italics="true" pageId="41" pageNumber="42">Praeexogyra acuminata</emphasis>
</taxonomicName>
. However, “ 
<collectingCountry id="F32E7651C0304609FCDEFCE3FCC63034" box="[801,821,800,823]" name="Iceland" pageId="41" pageNumber="42">
<emphasis id="B94DEAD3C0304609FCDEFCE3FCC63034" box="[801,821,800,823]" italics="true" pageId="41" pageNumber="42">O</emphasis>
</collectingCountry>
.” 
<taxonomicName id="4C394D42C0304609FCACFCDCFC4C303B" box="[851,959,799,824]" class="Bivalvia" family="Gryphaeidae" genus="Praeexogyra" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="hebridica">
<emphasis id="B94DEAD3C0304609FCACFCDCFC4C303B" box="[851,959,799,824]" italics="true" pageId="41" pageNumber="42">hebridica</emphasis>
</taxonomicName>
is extensively chambered and euryhaline (
<bibRefCitation id="EFA84B30C0304609FF61FC87FE5A305E" author="Hudson" box="[158,425,836,861]" pageId="41" pageNumber="42" refString="Hudson, J. D. &amp; Palmer, T. J. (1976) A euryhaline oyster from the Middle Jurassic and the origin of true oysters. Palaeontology, 19 (1), 79 - 93." type="journal article" year="1976">Hudson &amp; Palmer 1976</bibRefCitation>
) whereas 
<taxonomicName id="4C394D42C0304609FDE5FC86FD58305F" box="[538,683,837,860]" class="Bivalvia" family="Gryphaeidae" genus="Praeexogyra" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="acuminata">
<emphasis id="B94DEAD3C0304609FDE5FC86FD58305F" box="[538,683,837,860]" italics="true" pageId="41" pageNumber="42">P. acuminata</emphasis>
</taxonomicName>
is an essentially compact foliated (
<bibRefCitation id="EFA84B30C0304609FBCDFC87FB23305F" author="Siewert" box="[1074,1232,836,861]" pageId="41" pageNumber="42" refString="Siewert, W. (1972) Schalenbau und Stammesgeschichte der Austern. Stuttgarter Beitrage zur Naturkunde, B, 1, 1 - 57." type="journal article" year="1972">Siewert, 1972</bibRefCitation>
) euhaline species, co-occurring with ammonites in 
<collectingCountry id="F32E7651C0304609FDF3FCA4FD9A3083" box="[524,617,871,896]" name="United Kingdom" pageId="41" pageNumber="42">England</collectingCountry>
as well as in 
<collectingCountry id="F32E7651C0304609FCF5FCA4FC633083" box="[778,912,871,896]" name="Switzerland" pageId="41" pageNumber="42">Switzerland</collectingCountry>
(
<bibRefCitation id="EFA84B30C0304609FC5FFCA4FC6530A6" author="Arkell" pageId="41" pageNumber="42" refString="Arkell, W. J. (1934) The oysters of the Fuller's Earth and the evolution and nomenclature of the Upper Jurassic Catinulas and Gryphaeas. Proceedings of the Cotteswold Naturalists' Field Club, 25, 21 - 68." type="journal article" year="1934">
Arkell 1934; own data from the “ 
<taxonomicName id="4C394D42C0304609FADCFCABFA6F307C" box="[1315,1436,872,895]" class="Bivalvia" family="Gryphaeidae" genus="Praeexogyra" higherTaxonomySource="GBIF" kingdom="Animalia" order="Pterioida" pageId="41" pageNumber="48" phylum="Mollusca" rank="species" species="acuminata">
<emphasis id="B94DEAD3C0304609FADCFCABFA6F307C" box="[1315,1436,872,895]" italics="true" pageId="41" pageNumber="42">Acuminata</emphasis>
</taxonomicName>
Beds” of the Hauptrogenstein Formation, 
<collectingCountry id="F32E7651C0304609FD92FC4FFD2630A7" box="[621,725,908,932]" name="Germany" pageId="41" pageNumber="42">Germany</collectingCountry>
and 
<collectingCountry id="F32E7651C0304609FCF4FC4FFC6530A6" box="[779,918,908,933]" name="Switzerland" pageId="41" pageNumber="42">Switzerland</collectingCountry>
</bibRefCitation>
).
</paragraph>
<paragraph id="8B8636C1C0304609FF38FC6CFB4D377E" blockId="41.[151,1436,151,1149]" pageId="41" pageNumber="42">
Shell chambering and euryhaline preference may indicate a closer, perhaps congeneric relationship with “ 
<emphasis id="B94DEAD3C0304609FA89FC73FA7C30C4" box="[1398,1423,944,967]" italics="true" pageId="41" pageNumber="42">C.</emphasis>
” 
<taxonomicName id="4C394D42C0304609FF68FC16FEFF30EF" box="[151,268,981,1004]" class="Bivalvia" family="Ostreidae" genus="Crassostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="tetoriensis">
<emphasis id="B94DEAD3C0304609FF68FC16FEFF30EF" box="[151,268,981,1004]" italics="true" pageId="41" pageNumber="42">tetoriensis</emphasis>
</taxonomicName>
. Shell chambering could also indicate a link to 
<taxonomicName id="4C394D42C0304609FCB7FC17FC2530EE" box="[840,982,980,1005]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C0304609FCB7FC17FC2530EE" box="[840,982,980,1005]" italics="true" pageId="41" pageNumber="42">Helvetostrea</emphasis>
</taxonomicName>
. However, the species differs from all 
<taxonomicName id="4C394D42C0304609FF68FC34FED63713" box="[151,293,1015,1040]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C0304609FF68FC34FED63713" box="[151,293,1015,1040]" italics="true" pageId="41" pageNumber="42">Helvetostrea</emphasis>
</taxonomicName>
species by its more ventrally positioned, crescentic to reniform PAM without ventral shell buttress, with a pointed umbo, usually tiny attachment area, short ligament area, generally slender 
<taxonomicName id="4C394D42C0304609FB13FBDFFACE3736" box="[1260,1341,1052,1077]" class="Bivalvia" family="Ostreidae" genus="Actinostreon" higherTaxonomySource="GBIF" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="42" phylum="Mollusca" rank="species" species="outline">outline</taxonomicName>
, curved posterodorsal margin, and antimarginal riblets and furrows, especially the early ontogenetic ribbed “ 
<taxonomicName id="4C394D42C0304609FAD2FBFCFA7C375B" ID-CoL="3JHH" box="[1325,1423,1087,1112]" class="Leotiomycetes" family="Pezizellaceae" genus="Catinula" higherTaxonomySource="CoL" kingdom="Fungi" order="Helotiales" pageId="41" pageNumber="42" phylum="Ascomycota" rank="genus">
<emphasis id="B94DEAD3C0304609FAD2FBFCFA7C375B" box="[1325,1423,1087,1112]" italics="true" pageId="41" pageNumber="42">Catinula</emphasis>
</taxonomicName>
” stage (
<bibRefCitation id="EFA84B30C0304609FF20FBA7FE98377F" author="Arkell" box="[223,363,1124,1149]" pageId="41" pageNumber="42" refString="Arkell, W. J. (1934) The oysters of the Fuller's Earth and the evolution and nomenclature of the Upper Jurassic Catinulas and Gryphaeas. Proceedings of the Cotteswold Naturalists' Field Club, 25, 21 - 68." type="journal article" year="1934">Arkell 1934</bibRefCitation>
; 
<bibRefCitation id="EFA84B30C0304609FE89FBA7FD70377E" author="Hudson" box="[374,643,1124,1149]" pageId="41" pageNumber="42" refString="Hudson, J. D. &amp; Palmer, T. J. (1976) A euryhaline oyster from the Middle Jurassic and the origin of true oysters. Palaeontology, 19 (1), 79 - 93." type="journal article" year="1976">Hudson &amp; Palmer 1976</bibRefCitation>
). In addition, all 
<taxonomicName id="4C394D42C0304609FCBDFBA7FC23377E" box="[834,976,1124,1149]" class="Bivalvia" family="Gryphaeidae" genus="Helvetostrea" kingdom="Animalia" order="Ostreoida" pageId="41" pageNumber="112" phylum="Mollusca" rank="genus" status="gen. nov.">
<emphasis id="B94DEAD3C0304609FCBDFBA7FC23377E" box="[834,976,1124,1149]" italics="true" pageId="41" pageNumber="42">Helvetostrea</emphasis>
</taxonomicName>
species are euhaline.
</paragraph>
</subSubSection>
</treatment>
</document>