152 lines
35 KiB
XML
152 lines
35 KiB
XML
<document id="D57C3A4495DCE050E82594BD4BA5B691" ID-DOI="10.5281/zenodo.3678101" ID-GBIF-Dataset="0caf2b3f-f9ed-4f87-8bdd-5cf8288f4d02" ID-Zenodo-Dep="3678101" IM.bibliography_requiresApprovalFor="plazi" IM.metadata_requiresApprovalFor="plazi" IM.taxonomicNames_requiresApprovalFor="plazi" checkinTime="1582279042616" checkinUser="jeremy" docAuthor="Tarsitano, Samuel" docDate="1983" docId="03FAE2511E3DFFC0FF72FA2AFE92F9B0" docLanguage="en" docName="Tarsitano1983ABBYY_2.pdf.imf" docOrigin="Acta Palaeontologica Polonica 28" docStyle="DocumentStyle{}" docTitle="Thecodontia" docType="treatment" docVersion="11" lastPageNumber="253" masterDocId="FFC39A291E3CFFC5FFB0FF82FFEAFFEF" masterDocTitle="Stance and gait in theropod dinosaurs" masterLastPageNumber="264" masterPageNumber="251" pageNumber="252" updateTime="1698720973335" updateUser="plazi">
|
||
<mods:mods id="EC3424304C321537168E6DEF3EC50DAF" xmlns:mods="http://www.loc.gov/mods/v3">
|
||
<mods:titleInfo id="DA5F27277EBD56C265E7D00E78D8583A">
|
||
<mods:title id="BA2F6C019C967BE7C5CD053645CE0DB1">Stance and gait in theropod dinosaurs</mods:title>
|
||
</mods:titleInfo>
|
||
<mods:name id="C2FC5C1C69178603AD9F495207C2B982" type="personal">
|
||
<mods:role id="C9F167C7A31D72FDAFC8E8C34BC050E2">
|
||
<mods:roleTerm id="1B8A785A0DFE02BD54BCB3998182DD93">Author</mods:roleTerm>
|
||
</mods:role>
|
||
<mods:namePart id="6D8865501CF91B340DF9F0E1A86869EB">Tarsitano, Samuel</mods:namePart>
|
||
</mods:name>
|
||
<mods:typeOfResource id="34448E101F0BEA6010982BC0755D92A0">text</mods:typeOfResource>
|
||
<mods:relatedItem id="598C8C48CE6DA1FD8E30EA708E6D6341" type="host">
|
||
<mods:titleInfo id="2E72CCF19435ACE2121F9D487A3D2A57">
|
||
<mods:title id="74BAC068A5CB8A25C076DA6DCAA1C292">Acta Palaeontologica Polonica</mods:title>
|
||
</mods:titleInfo>
|
||
<mods:part id="87D33C375F3A0E8FD32448D2DB0F668D">
|
||
<mods:date id="007D9B7CE28BA900F918739F34A484F7">1983</mods:date>
|
||
<mods:detail id="A98C24FA11A56ACA2A6F1D394AF03338" type="volume">
|
||
<mods:number id="3F7440526D7701151BF58F65CDD8CCE9">28</mods:number>
|
||
</mods:detail>
|
||
<mods:extent id="3F800DF0425A80E5BB7FD4583E2906A2" unit="page">
|
||
<mods:start id="FEE50792CEE8E35105F2BAA9CBB13AFF">251</mods:start>
|
||
<mods:end id="5D1D6999BFC553F216F9046EC50900E8">264</mods:end>
|
||
</mods:extent>
|
||
</mods:part>
|
||
</mods:relatedItem>
|
||
<mods:classification id="A826476F7015FFBA89AE27FD0A4F2A6A">journal article</mods:classification>
|
||
<mods:identifier id="B4A457C0DB91E69820D69728058A23BB" type="DOI">10.5281/zenodo.3678101</mods:identifier>
|
||
<mods:identifier id="BEFBB746147D4EAD345F97D3A4724A38" type="GBIF-Dataset">0caf2b3f-f9ed-4f87-8bdd-5cf8288f4d02</mods:identifier>
|
||
<mods:identifier id="65DE1B6D5CF8DBF2913D5750B0D13B66" type="Zenodo-Dep">3678101</mods:identifier>
|
||
</mods:mods>
|
||
<treatment id="03FAE2511E3DFFC0FF72FA2AFE92F9B0" ID-DOI="http://doi.org/10.5281/zenodo.3682313" ID-GBIF-Taxon="162245243" ID-Zenodo-Dep="3682313" LSID="urn:lsid:plazi:treatment:03FAE2511E3DFFC0FF72FA2AFE92F9B0" httpUri="http://treatment.plazi.org/id/03FAE2511E3DFFC0FF72FA2AFE92F9B0" lastPageId="5" lastPageNumber="253" pageId="1" pageNumber="252">
|
||
<subSubSection id="C34900CC1E3DFFC4FF72FA2AFD58F750" pageId="1" pageNumber="252" type="nomenclature">
|
||
<paragraph id="8BEC53471E3DFFC4FF72FA2AFD58F750" blockId="1.[127,1633,1448,2562]" pageId="1" pageNumber="252">
|
||
Although progress has been made in understanding the phylogeny of
|
||
<taxonomicName id="4C5328C41E3DFFC4FF30FA5EFEB9F9E9" box="[128,339,1500,1542]" class="Reptilia" kingdom="Animalia" order="Thecodontia" pageId="1" pageNumber="252" phylum="Chordata" rank="order">thecodonts</taxonomicName>
|
||
(Charig and
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FDC6FA5EFCA9F9E9" author="CHARIG, A.J. & REIG, O. A." box="[630,835,1500,1542]" journalOrPublisher="Biol. J. Linn. Soc." pageId="1" pageNumber="252" pagination="121-171" part="22" refId="ref4913" refString="- and REIG, O. A. 1970. The classification of the Proterosuchia. - Biol. J. Linn. Soc., 22, 121 - 171." title="The classification of the Proterosuchia" type="book" year="1970">Reig 1970</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FCD3FA5EFB4CF9E9" author="BONAPARTE, J. F." box="[867,1190,1500,1542]" journalOrPublisher="Acta Geol. Lilloana" pageId="1" pageNumber="252" pagination="5 - 90" part="13" refId="ref4704" refString="BONAPARTE, J. F. 1975: Nuevos materiales de Lagosuchus talampayensis Romer (Thecodontia-Pseudosuchia) y su significado en el origen de los Saurischia. Chanarense Inferior, Triasico Medio de Argentina. - Acta Geol. Lilloana, 13, 5 - 90." title="Nuevos materiales de Lagosuchus talampayensis Romer (Thecodontia-Pseudosuchia) y su significado en el origen de los Saurischia. Chanarense Inferior, Triasico Medio de Argentina" type="journal article" year="1975">Bonaparte 1975</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FB76FA5EFA95F9E9" author="SILL, W. D." box="[1222,1407,1500,1542]" journalOrPublisher="Bull. Mus. Comp. Zool." pageId="1" pageNumber="252" pagination="317 - 362" part="146" refId="ref5837" refString="SILL, W. D. 1974. The anatomy of Saurosuchus galilei and the relationships of the rauisuchid thecodonts. - Bull. Mus. Comp. Zool., 146, 317 - 362." title="The anatomy of Saurosuchus galilei and the relationships of the rauisuchid thecodonts" type="journal article" year="1974">Sill 1974</bibRefCitation>
|
||
), they are still largely represented by grades instead of clades. This is due to the poor fossil record of thecodonts and the incomplete preservation of those specimens which are known. This is certainly true of the small upland and/or arboreal forms that must have existed, as evidenced by
|
||
<emphasis id="B9278F551E3DFFC4FA76F92DFEE5F8E0" italics="true" pageId="1" pageNumber="252">
|
||
<taxonomicName id="4C5328C41E3DFFC4FA76F92DFEE3F8E0" class="Reptilia" family="Lagosuchidae" genus="Longisquama" higherTaxonomySource="GBIF" kingdom="Animalia" order="Archosauromorpha" pageId="1" pageNumber="252" phylum="Chordata" rank="genus">Longisquama</taxonomicName>
|
||
.
|
||
</emphasis>
|
||
The present paper uses the term Pseudosuchia as, at least, the ancestors of theropods (
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FD33F899FC6BF8AA" author="BROOM, R." box="[643,897,1819,1861]" journalOrPublisher="Proc. Zool. Soc. London" pageId="1" pageNumber="252" pagination="619 - 633" part="1913" refId="ref4827" refString="BROOM, R. 1913. On the South African pseudosuchian Euparkeria and allied genera. - Proc. Zool. Soc. London, 1913, 619 - 633." title="On the South African pseudosuchian Euparkeria and allied genera" type="journal article" year="1913">Broom 1913</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FC18F899FB4BF8AA" author="HUENE, F. R. von" box="[936,1185,1819,1861]" journalOrPublisher="Acta Zoologica" pageId="1" pageNumber="252" pagination="360 - 380" part="2" refId="ref5348" refString="HUENE, F. R. von. 1921. Neue Pseudosuchier und Coelurosaurier aus dem Wiirttem- bergischen Keupen. - Acta Zoologica, 2, 360 - 380." title="Neue Pseudosuchier und Coelurosaurier aus dem Wiirttem- bergischen Keupen" type="journal article" year="1921">Huene 1921</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FB77F899FA3CF8AA" author="WALKER, A. D." box="[1223,1494,1819,1861]" journalOrPublisher="Phil. Trans. Roy. Soc. (B)" pageId="1" pageNumber="252" pagination="53 - 134" part="248" refId="ref6034" refString="WALKER, A. D. 1964. Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs. - Phil. Trans. Roy. Soc. (B), 248, 53 - 134." title="Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs" type="journal article" year="1964">Walker 1964</bibRefCitation>
|
||
). This relationship is based on the synapomorphies of the skull, tarsus and ischia (
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FEA6F804FDE7F85F" author="BROOM, R." box="[278,525,1926,1968]" journalOrPublisher="Proc. Zool. Soc. London" pageId="1" pageNumber="252" pagination="619 - 633" part="1913" refId="ref4827" refString="BROOM, R. 1913. On the South African pseudosuchian Euparkeria and allied genera. - Proc. Zool. Soc. London, 1913, 619 - 633." title="On the South African pseudosuchian Euparkeria and allied genera" type="journal article" year="1913">Broom 1913</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FD9DF804FCDEF85F" author="WALKER, A. D." box="[557,820,1926,1968]" journalOrPublisher="Phil. Trans. Roy. Soc. (B)" pageId="1" pageNumber="252" pagination="53 - 134" part="248" refId="ref6034" refString="WALKER, A. D. 1964. Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs. - Phil. Trans. Roy. Soc. (B), 248, 53 - 134." title="Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs" type="journal article" year="1964">Walker 1964</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FCE5F804FAC4F85F" author="TARSITANO, S." box="[853,1326,1926,1968]" journalOrPublisher="City University of New York" pageId="1" pageNumber="264" refId="ref5947" refString="TARSITANO, S. 1981. Pelvic and hindlimb musculature in archosaurian reptiles. Ph. D. thesis, City University of New York." title="Pelvic and hindlimb musculature in archosaurian reptiles" type="book" year="1981">Tarsitano, Ph.D. thesis</bibRefCitation>
|
||
). Ancestors of other dinosaurian groups as well as birds may also be relegated to the Pseudosuchia as they become known (
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FC63F870FAFCF7F3" author="HEILMANN, G." bookContentInfo="208 pp." box="[979,1302,2034,2076]" journalOrPublisher="Witherby, London" pageId="1" pageNumber="252" refId="ref5249" refString="HEILMANN, G. 1926. Origin of the Birds. 208 pp. Witherby, London." title="Origin of the Birds" type="book" year="1926">Heilmann 1926</bibRefCitation>
|
||
). It should be understood however, that the avian ancestor would not belong to the same group of pseudosuchians which were ancestral to any dinosaur taxon (
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FF21F717FD4AF750" author="TARSITANO, S. & HECHT, M. K." box="[145,672,2197,2239]" journalOrPublisher="Zool. J. Linn. Soc." pageId="1" pageNumber="252" pagination="149 - 182" part="69" refId="ref5973" refString="- and HECHT, M. K. 1980. A reconsideration of the reptilian relationships of Archaeopteryx. - Zool. J. Linn. Soc., 69 (2), 149 - 182." title="A reconsideration of the reptilian relationships of Archaeopteryx" type="journal article" year="1980">Tarsitano and Hecht 1980</bibRefCitation>
|
||
).
|
||
</paragraph>
|
||
</subSubSection>
|
||
<subSubSection id="C34900CC1E3DFFC0FF74F74BFE92F9B0" lastPageId="5" lastPageNumber="256" pageId="1" pageNumber="252" type="description">
|
||
<paragraph id="8BEC53471E3DFFC7FF74F74BFB7CF837" blockId="1.[127,1633,1448,2562]" lastBlockId="2.[118,1613,204,2547]" lastPageId="2" lastPageNumber="253" pageId="1" pageNumber="252">
|
||
The locomotory morphology of pseudosuchian thecodonts is essentially crocodilian in nature (
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FDE8F77DFCAEF6C6" author="KREBS, B." box="[600,836,2303,2345]" journalOrPublisher="Palaont. Z." pageId="1" pageNumber="252" pagination="88 - 95" part="57" refId="ref5378" refString="KREBS, B. 1963. Bau und Funktion des Tarsus eines Pseudosuchiers aus der Trias des ivionte San Giorgia (Kanton Tessin, Schweiz). - Palaont. Z., 57, 88 - 95." title="Bau und Funktion des Tarsus eines Pseudosuchiers aus der Trias des ivionte San Giorgia (Kanton Tessin, Schweiz)" type="journal article" year="1963">Krebs 1963</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FCD5F77DFB84F6C6" author="OSTROM, J. H." box="[869,1134,2303,2345]" journalOrPublisher="Biol. J. Linn. Soc." pageId="1" pageNumber="252" pagination="91 - 182" part="8" refId="ref5640" refString="- 1976. Archaeopteryx and the origin of birds. - Biol. J. Linn. Soc., 8, 91 - 182." title="Archaeopteryx and the origin of birds" type="journal article" year="1976">Ostrom 1976</bibRefCitation>
|
||
). Both crocodilians and pseudosuchians are mainly quadrupedal. This type of locomotion is correlated to, or a consequence of, a sprawling gait and is tied to the structure of the tarsus, overlapping metatarsals, femur, hip joint and pelvic and hindlimb musculature (
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FC38F655FB20F5EE" author="SCHAEFFER, B." box="[904,1226,2519,2561]" journalOrPublisher="Bull. Am. Mus. Nat. Hist" pageId="1" pageNumber="252" pagination="395 - 472" part="78" refId="ref5800" refString="SCHAEFFER, B. 1941. The morphological and functional evolution of the tarsus in amphibians and reptiles. - Bull. Am. Mus. Nat. Hist., 78, 395 - 472." title="The morphological and functional evolution of the tarsus in amphibians and reptiles" type="journal article" year="1941">Schaeffer 1941</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3DFFC4FB46F655F9BCF5EE" author="BRINKMAN, D." box="[1270,1622,2519,2561]" journalOrPublisher="Can. J. Zool." pageId="1" pageNumber="252" pagination="277 - 289" part="58" refId="ref4751" refString="BRINKMAN, D. 1980 a. Structural correlates of tarsal and metatarsal functioning in Iguana (Lacertilia, Iguanidae) and other lizards. - - Can. J. Zool., 58 (2), 277 - 289." title="Structural correlates of tarsal and metatarsal functioning in Iguana (Lacertilia, Iguanidae) and other lizards" type="journal article" year="1980">Brinkman 1980a</bibRefCitation>
|
||
,
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FFCAFF4EFF06FF19" author="BRINKMAN, D." box="[122,236,204,246]" journalOrPublisher="Can. J. Zool." pageId="2" pageNumber="253" pagination="2187 - 2200" part="58" refId="ref4794" refString="- 1980 b. The hindlimb step cycle of Cazman sclerops and the mechanics of the crocodiiian tarsus and metatarsus. - Ibidem, 58 (12), 2187 - 2200." title="The hindlimb step cycle of Cazman sclerops and the mechanics of the crocodiiian tarsus and metatarsus" type="journal article" year="1980">1980b</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FEB4FF4EFD20FF19" author="TARSITANO, S." box="[260,714,204,246]" journalOrPublisher="City University of New York" pageId="2" pageNumber="264" refId="ref5947" refString="TARSITANO, S. 1981. Pelvic and hindlimb musculature in archosaurian reptiles. Ph. D. thesis, City University of New York." title="Pelvic and hindlimb musculature in archosaurian reptiles" type="book" year="1981">Tarsitano, Ph.D. thesis</bibRefCitation>
|
||
; Hecht and Tarsitano, in press). Crocodilians and pseudosuchians have a crocodilian tarsus (
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FB81FE83FAFEFEC4" author="KREBS, B." box="[1073,1300,257,299]" journalOrPublisher="Palaont. Z." pageId="2" pageNumber="253" pagination="88 - 95" part="57" refId="ref5378" refString="KREBS, B. 1963. Bau und Funktion des Tarsus eines Pseudosuchiers aus der Trias des ivionte San Giorgia (Kanton Tessin, Schweiz). - Palaont. Z., 57, 88 - 95." title="Bau und Funktion des Tarsus eines Pseudosuchiers aus der Trias des ivionte San Giorgia (Kanton Tessin, Schweiz)" type="journal article" year="1963">Krebs 1963</bibRefCitation>
|
||
) or a variation of this ankle type termed the “crocodilian reversed tarsus” (
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FAE3FEB5FF39FE7A" author="CRUICKSHANK, A. R. I." journalOrPublisher="S. Afr. J. Sci." pageId="2" pageNumber="253" pagination="168 - 178" part="75" refId="ref4979" refString="CRUICKSHANK, A. R. I. 1979. The ankle joint in some early archosaurs. - S. Afr. J. Sci., 75, 168 - 178." title="The ankle joint in some early archosaurs" type="journal article" year="1979">Cruickshank 1979</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FF47FEE9FDC2FE7A" author="THULBORN, R. A." box="[247,552,363,405]" journalOrPublisher="Alcheringia" pageId="2" pageNumber="253" pagination="241 - 261" part="4" refId="ref6011" refString="THULBORN, R. A. 1980. The ankle joints of archosaurs. - Alcheringia, 4, 241 - 261." title="The ankle joints of archosaurs" type="journal article" year="1980">Thulborn 1980</bibRefCitation>
|
||
). In the crocodilian and pseudosuchian tarsus the proximal tarsal elements play a key role in locomotion (
|
||
<figureCitation id="13684FC21E3EFFC7FAF5FE22FA24FE25" box="[1349,1486,416,458]" captionStart="Fig. 1" captionStartId="3.[122,180,2258,2290]" captionTargetBox="[132,1638,184,2234]" captionTargetPageId="3" captionText="Fig. 1. Various tarsal elements of archosaurs: a distal view of the right tarsus of a eusuchian crocodilian; b proximal view of the right calcaneum of the pseudosuchian Prestosuchus; c lateral view of the left calcaneum of a eusuchian crocodilian; d lateral view of the left calcaneum of a theropod dinosaur AC articular cartilage; AH anterior hollow of the astragulus; CT calcaneal tuber; DR distal roller of the astragulus; DT distal tarsal four facet of the calcaneum; F fibula; FC fibular condyle of the calcaneum; P peg of the astragalus; S socket of the calcaneum; T tongue of the calcaneum; TI tibia." figureDoi="http://doi.org/10.5281/zenodo.3678103" httpUri="https://zenodo.org/record/3678103/files/figure.png" pageId="2" pageNumber="253">fig. 1a</figureCitation>
|
||
). The astragalus is bound to the tibia while the calcaneum moves with the pes (
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FF36FD8EFE45FDD9" author="SCHAEFFER, B." box="[134,431,524,566]" journalOrPublisher="Bull. Am. Mus. Nat. Hist" pageId="2" pageNumber="264" pagination="395 - 472" part="78" refId="ref5800" refString="SCHAEFFER, B. 1941. The morphological and functional evolution of the tarsus in amphibians and reptiles. - Bull. Am. Mus. Nat. Hist., 78, 395 - 472." title="The morphological and functional evolution of the tarsus in amphibians and reptiles" type="journal article" year="1941">Schaeffer 1941</bibRefCitation>
|
||
). Thus there exists an intratarsal joint of a complex nature between the two proximal tarsals. The important features of this joint will be described here for convenience. A comprehensive description can be found in Hecht and Tarsitano (in press). The medial element, the astragalus, bears a peg-like structure on its lateral surface which articul ates with a socket on the medial surface of the calcaneum. This articul ation comprises the primary joint between the calcaneum and astragalus. The secondary joint occurs between the astragalar trochlear found on the posterior surface of the astragalus and the tongue of the calcaneum (
|
||
<figureCitation id="13684FC21E3EFFC7FF34FC6CFEEDFBF7" box="[132,263,1006,1048]" captionStart="Fig. 1" captionStartId="3.[122,180,2258,2290]" captionTargetBox="[132,1638,184,2234]" captionTargetPageId="3" captionText="Fig. 1. Various tarsal elements of archosaurs: a distal view of the right tarsus of a eusuchian crocodilian; b proximal view of the right calcaneum of the pseudosuchian Prestosuchus; c lateral view of the left calcaneum of a eusuchian crocodilian; d lateral view of the left calcaneum of a theropod dinosaur AC articular cartilage; AH anterior hollow of the astragulus; CT calcaneal tuber; DR distal roller of the astragulus; DT distal tarsal four facet of the calcaneum; F fibula; FC fibular condyle of the calcaneum; P peg of the astragalus; S socket of the calcaneum; T tongue of the calcaneum; TI tibia." figureDoi="http://doi.org/10.5281/zenodo.3678103" httpUri="https://zenodo.org/record/3678103/files/figure.png" pageId="2" pageNumber="253">fig. 1b</figureCitation>
|
||
). The tongue process lies directly posterior to the calcaneal socket and projects medially to glide over the trochlea of the astragalus. The calcaneum (
|
||
<figureCitation id="13684FC21E3EFFC7FED6FBDBFDDDFB6C" box="[358,567,1113,1155]" captionStart="Fig. 1" captionStartId="3.[122,180,2258,2290]" captionTargetBox="[132,1638,184,2234]" captionTargetPageId="3" captionText="Fig. 1. Various tarsal elements of archosaurs: a distal view of the right tarsus of a eusuchian crocodilian; b proximal view of the right calcaneum of the pseudosuchian Prestosuchus; c lateral view of the left calcaneum of a eusuchian crocodilian; d lateral view of the left calcaneum of a theropod dinosaur AC articular cartilage; AH anterior hollow of the astragulus; CT calcaneal tuber; DR distal roller of the astragulus; DT distal tarsal four facet of the calcaneum; F fibula; FC fibular condyle of the calcaneum; P peg of the astragalus; S socket of the calcaneum; T tongue of the calcaneum; TI tibia." figureDoi="http://doi.org/10.5281/zenodo.3678103" httpUri="https://zenodo.org/record/3678103/files/figure.png" pageId="2" pageNumber="253">fig. 1a, b, c</figureCitation>
|
||
.) is also moveable against the fibula. The calcaneum bears proximally a condyle (fibular condyle) which is free to rotate under a ventrally cupshaped cartilage ventral to the fibula (
|
||
<figureCitation id="13684FC21E3EFFC7FAE9FB47FA3DFB00" box="[1369,1495,1221,1263]" captionStart="Fig" captionStartId="3.[122,180,2258,2290]" captionTargetBox="[132,1638,184,2234]" captionTargetPageId="3" captionText="Fig. 1. Various tarsal elements of archosaurs: a distal view of the right tarsus of a eusuchian crocodilian; b proximal view of the right calcaneum of the pseudosuchian Prestosuchus; c lateral view of the left calcaneum of a eusuchian crocodilian; d lateral view of the left calcaneum of a theropod dinosaur AC articular cartilage; AH anterior hollow of the astragulus; CT calcaneal tuber; DR distal roller of the astragulus; DT distal tarsal four facet of the calcaneum; F fibula; FC fibular condyle of the calcaneum; P peg of the astragalus; S socket of the calcaneum; T tongue of the calcaneum; TI tibia." figureDoi="http://doi.org/10.5281/zenodo.3678103" httpUri="https://zenodo.org/record/3678103/files/figure.png" pageId="2" pageNumber="253">fig. 1c</figureCitation>
|
||
). The weight of the fibula is born by the fibula facet of the astragalus. The calcaneum bears posteriolaterally a tuber which serves to change the direction of pull of the foot extensors and tendons of the
|
||
<emphasis id="B9278F551E3EFFC7FB4EFAE4FECFFA2A" italics="true" pageId="2" pageNumber="253">M. flexor tibialis externus</emphasis>
|
||
and
|
||
<emphasis id="B9278F551E3EFFC7FE38FA19FD82FA2A" box="[392,616,1435,1477]" italics="true" pageId="2" pageNumber="253">M. ambiens</emphasis>
|
||
as they make their way to metatarsal V (
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FA16FA19FEF6FA15" author="SCHAEFFER, B." journalOrPublisher="Bull. Am. Mus. Nat. Hist" pageId="2" pageNumber="264" pagination="395 - 472" part="78" refId="ref5800" refString="SCHAEFFER, B. 1941. The morphological and functional evolution of the tarsus in amphibians and reptiles. - Bull. Am. Mus. Nat. Hist., 78, 395 - 472." title="The morphological and functional evolution of the tarsus in amphibians and reptiles" type="journal article" year="1941">Schaeffer 1941</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FEF2FA52FDAEFA15" author="GADOW, H." box="[322,580,1488,1530]" journalOrPublisher="Morphol. Jb." pageId="2" pageNumber="253" pagination="329 - 466" part="7" refId="ref5013" refString="GADOW, H. 1882. Beitrage zur Myologie der hintern Extremitat der Reptilien. - Morphol. Jb., 7, 329 - 466." title="Beitrage zur Myologie der hintern Extremitat der Reptilien" type="journal article" year="1882">Gadow 1882</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FDDAFA52FC2EFA15" author="BRINKMAN, D." box="[618,964,1488,1530]" journalOrPublisher="Can. J. Zool." pageId="2" pageNumber="253" pagination="2187 - 2200" part="58" refId="ref4794" refString="- 1980 b. The hindlimb step cycle of Cazman sclerops and the mechanics of the crocodiiian tarsus and metatarsus. - Ibidem, 58 (12), 2187 - 2200." title="The hindlimb step cycle of Cazman sclerops and the mechanics of the crocodiiian tarsus and metatarsus" type="journal article" year="1980">Brinkman 1980b</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FC5AFA52FA25FA15" author="TARSITANO, S." box="[1002,1487,1488,1530]" journalOrPublisher="City University of New York" pageId="2" pageNumber="264" refId="ref5947" refString="TARSITANO, S. 1981. Pelvic and hindlimb musculature in archosaurian reptiles. Ph. D. thesis, City University of New York." title="Pelvic and hindlimb musculature in archosaurian reptiles" type="book" year="1981">Tarsitano, Ph.D. thesis</bibRefCitation>
|
||
). The femur of pseudosuchians and crocodilians is also very similar. The head of the femur is not medially extended to form a roller surface (
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FA76F9B9FF39F975" author="HOTTON, N." editor="R. D. K. Thomas & E. C. Olson" journalOrPublisher="Westview Press, Colorado" pageId="2" pageNumber="253" pagination="311 - 350" part="28" refId="ref5291" refString="HOTTON, N. 1980. An alternative to dinosaur endothermy: The happy Wanderers. In: R. D. K. Thomas and E. C. Olson (eds), A Cold Look at the Warm-Blooded Dinosaurs, AAAS Selected Symposium 28, 311 - 350. Westview Press, Colorado." title="An alternative to dinosaur endothermy: The happy Wanderers" type="journal article" volumeTitle="A Cold Look at the Warm-Blooded Dinosaurs" year="1980">Hotton 1980</bibRefCitation>
|
||
, and pers. comm.). Instead, the head is anterioposteriorly directed. There is also a lateral torsion in the femur so that the shaft of the bone does not lie in the same plane as the head. In this regard, the lateral femoral condyle is larger than its medial counterpart. Finally, although the acetabulum may be perforate, an overhanging shelf forming the dorsal boundary of the acetabulum which is essential to a hip roller joint and upright stance does not exist in pseudosuchians.
|
||
</paragraph>
|
||
<paragraph id="8BEC53471E3EFFC0FF0EF866FE92F9B0" blockId="2.[118,1613,204,2547]" lastBlockId="5.[126,1629,199,1631]" lastPageId="5" lastPageNumber="256" pageId="2" pageNumber="253">
|
||
The elements of the locomotory system of crocodilians and pseudo suchian thecodonts correspond to a mainly quadrupedal level of organiz ation. Their hindlimb morphology can now be explained in functional terms. In order for the intratarsal joint to function, the calcaneum must be free to rotate. This means that the pes must first be lifted from the lateral side. The foot extensors, the
|
||
<emphasis id="B9278F551E3EFFC7FCD8F770FB22F6F3" box="[872,1224,2290,2332]" italics="true" pageId="2" pageNumber="253">M. gastrocnemius</emphasis>
|
||
(tibial and fibular heads),
|
||
<emphasis id="B9278F551E3EFFC7FEBFF6A5FACBF6BE" box="[271,1313,2343,2385]" italics="true" pageId="2" pageNumber="253">M. peroneus, M. flexor tibialis externus, M. ambiens</emphasis>
|
||
and
|
||
<emphasis id="B9278F551E3EFFC7FA38F6A5FEC5F667" italics="true" pageId="2" pageNumber="253">M. caudo- femoralis</emphasis>
|
||
(by way of the
|
||
<emphasis id="B9278F551E3EFFC7FDCEF6DCFC03F667" box="[638,1001,2398,2440]" italics="true" pageId="2" pageNumber="253">M. gastrocnemius)</emphasis>
|
||
all are directed to the lateral side of the foot (
|
||
<figureCitation id="13684FC21E3EFFC7FE78F611FDAEF652" box="[456,580,2451,2493]" captionStart="Fig. 2" captionStartId="4.[113,169,1448,1480]" captionTargetBox="[168,736,222,1414]" captionTargetPageId="4" captionText="Fig. 2. Superficial shank muscles of a eusuchian crocodilian. FTE tendon of the M. flexor tibialis externus; GF fibular head of the M. gastrocnemius; PLA plantar aponeurosis; T tibia." figureDoi="http://doi.org/10.5281/zenodo.3678107" httpUri="https://zenodo.org/record/3678107/files/figure.png" pageId="2" pageNumber="253">figs. 2</figureCitation>
|
||
,
|
||
<figureCitation id="13684FC21E3EFFC7FDD0F611FD99F652" box="[608,627,2451,2493]" captionStart="Fig. 3" captionStartId="4.[914,969,1089,1121]" captionTargetBox="[788,1548,226,1070]" captionTargetPageId="4" captionText="Fig. 3. Lateral view of the left shank and pes of a eusuchian crocodilian. AMB M. ambiens; C calcaneum; FTE M. flexor tibialis externus; G M. gas trocnemius, fibular head; PA M. pero neus anterior; PP peroneus posterior; TCF tendon of the M. caudofemoralis attaching to the fibula; TCFM tendon of the M. caudofemoralis, forming the main origin for the fibular head of the M. gastrocnemius; TE tendon of the M. caudofemoralis to the extensor tendon of the knee; TFTE tendon of the M. flexor tibialis externus to the fifth metatarsus." figureDoi="http://doi.org/10.5281/zenodo.3678105" httpUri="https://zenodo.org/record/3678105/files/figure.png" pageId="2" pageNumber="253">3</figureCitation>
|
||
) in particular to the fifth metatarsal (
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FA36F611FF06F61C" author="BRINKMAN, D." journalOrPublisher="Can. J. Zool." pageId="2" pageNumber="253" pagination="2187 - 2200" part="58" refId="ref4794" refString="- 1980 b. The hindlimb step cycle of Cazman sclerops and the mechanics of the crocodiiian tarsus and metatarsus. - Ibidem, 58 (12), 2187 - 2200." title="The hindlimb step cycle of Cazman sclerops and the mechanics of the crocodiiian tarsus and metatarsus" type="journal article" year="1980">Brinkman 1980b</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FEBAF64BFDDDF61C" author="SCHAEFFER, B." box="[266,567,2505,2547]" journalOrPublisher="Bull. Am. Mus. Nat. Hist" pageId="2" pageNumber="253" pagination="395 - 472" part="78" refId="ref5800" refString="SCHAEFFER, B. 1941. The morphological and functional evolution of the tarsus in amphibians and reptiles. - Bull. Am. Mus. Nat. Hist., 78, 395 - 472." title="The morphological and functional evolution of the tarsus in amphibians and reptiles" type="journal article" year="1941">Schaeffer 1941</bibRefCitation>
|
||
;
|
||
<bibRefCitation id="EFC22EB61E3EFFC7FDE4F64BFBCDF61C" author="TARSITANO, S." box="[596,1063,2505,2547]" journalOrPublisher="City University of New York" pageId="2" pageNumber="264" refId="ref5947" refString="TARSITANO, S. 1981. Pelvic and hindlimb musculature in archosaurian reptiles. Ph. D. thesis, City University of New York." title="Pelvic and hindlimb musculature in archosaurian reptiles" type="book" year="1981">Tarsitano, Ph.D. thesis</bibRefCitation>
|
||
). Thus the muscular function coincides with that of the ankle. Since the pes is first lifted laterally, the metatarsals must overlap to brace the inside digits of the pes which supply the support and convey the applied force of the foot extensors to the ground. Furthermore, since the pes must be lifted from the lateral Side, the femur cannot be brought under the body and must be held at an angle to the vertical, hence the femoral torsion. All of the above stated morphology is part of one functional complex and is a level of organiz ation and not a clade. It is apparent that all saurischian dinosaurs have evolved from a pseudosuchian ancestry since the remmants of the croco dilian tarsus is to be seen in theropods, sauropods and prosauropods. The ischia and pubes of pseudosuchians are decidedly saurischian and not crocodilian. While episodes of bipedalism are not unknown in crocodilians, the normal mode of locomotion is quadrupedal. A bipedal posture is possible when enough momentum has been attained in order that the presacral region may be lifted (the vertebral column extended). Thus it is likely that pseudosuchians were also able to run bipedally in such fashion but this type of bipedalism should not be confused with that of theropods. The primitive method of balance in thecodontian and croco dilian bipedal progression is that of a cantilever system. In this system the downward torque of the presacral region is balanced by the down ward torque in the opposite direction produced by the tail. This system of balance is also used by bipedal lizards (
|
||
<bibRefCitation id="EFC22EB61E39FFC0FC4DFE51FB17FE12" author="SNYDER, R. C." box="[1021,1277,467,509]" journalOrPublisher="Copeia" pageId="5" pageNumber="256" pagination="129 - 137" refId="ref5874" refString="SNYDER, R. C. 1949. Bipedai locomotion of the lizard Basiliscus basiliscus. - Copeia, 1949. 129 - 137." title="Bipedai locomotion of the lizard Basiliscus basiliscus" type="book chapter" year="1949">Snyder 1949</bibRefCitation>
|
||
,
|
||
<bibRefCitation id="EFC22EB61E39FFC0FAAEFE51FA9DFE12" author="SNYDER, R. C." box="[1310,1399,467,509]" journalOrPublisher="Copeia" pageId="5" pageNumber="256" pagination="64 - 70" part="1952" refId="ref5899" refString="- 1952. Quadrupedal and bipedal locomotion in lizards. Ibidem, 1952, 64 - 70." title="Quadrupedal and bipedal locomotion in lizards" type="book" year="1952">1952</bibRefCitation>
|
||
,
|
||
<bibRefCitation id="EFC22EB61E39FFC0FA28FE51FA04FE12" author="SNYDER, R. C." box="[1432,1518,467,509]" journalOrPublisher="Am. J. Anat." pageId="5" pageNumber="256" pagination="1 - 46" part="95" refId="ref5917" refString="- 1954. The anatomy and function of the pelvis girdle and hindlimb in lizard locomotion. - Am J. Anat., 95, 1 - 46." title="The anatomy and function of the pelvis girdle and hindlimb in lizard locomotion" type="journal article" year="1954">1954</bibRefCitation>
|
||
) and bipedal dinosaurs (
|
||
<bibRefCitation id="EFC22EB61E39FFC0FDBBFD8AFC0CFDDD" author="TARSITANO, S." box="[523,998,520,562]" journalOrPublisher="City University of New York" pageId="5" pageNumber="264" refId="ref5947" refString="TARSITANO, S. 1981. Pelvic and hindlimb musculature in archosaurian reptiles. Ph. D. thesis, City University of New York." title="Pelvic and hindlimb musculature in archosaurian reptiles" type="book" year="1981">Tarsitano, Ph.D. thesis</bibRefCitation>
|
||
). Birds have adopted another system of bipedalism. The tail is not used as a counterbalance but is instead reduced for aerodynamic reasons. With the reduction of the tail in birds (including
|
||
<emphasis id="B9278F551E39FFC0FDBDFD2AFCA9FD3D" box="[525,835,680,722]" italics="true" pageId="5" pageNumber="256">
|
||
<taxonomicName id="4C5328C41E39FFC0FDBDFD2AFCDFFD3D" authority="Meyer, 1861" box="[525,821,680,722]" class="Reptilia" family="Archaeopterygidae" genus="Archaeopteryx" kingdom="Animalia" order="Dinosauria" pageId="5" pageNumber="256" phylum="Chordata" rank="genus">Archaeopteryx</taxonomicName>
|
||
)
|
||
</emphasis>
|
||
the pubes had to grow posteriorly in order that the viscera could be shifted under the pelvis thereby reducing the presacral downward torque. This adaptation would shift the center of gravity posteriorly. The shortening of the femur and the elongation of the tibiotarsus coincided with the posterior shift of the center of gravity under the pelvis. The result of these modifications of the pelvis and hindlimb in birds is that the tibiotarsus bone-muscle complex is the primary system of locomotion. In thecodonts, crocodilians and dinosaurs it is the tail-femoral-bone-muscle complex which is most important in locomotion. Thus, in order to interpret the osteology and muscle scars of theropods, it is better to compare theropods to crocodilians which have the same morphology as the pseudosuchian predecessors of theropods. I have found that of the muscles which leave scars on the pelvis and femur (
|
||
<bibRefCitation id="EFC22EB61E39FFC0FE97FAE2FCE7FA65" author="TARSITANO, S." box="[295,781,1376,1418]" journalOrPublisher="City University of New York" pageId="5" pageNumber="264" refId="ref5947" refString="TARSITANO, S. 1981. Pelvic and hindlimb musculature in archosaurian reptiles. Ph. D. thesis, City University of New York." title="Pelvic and hindlimb musculature in archosaurian reptiles" type="book" year="1981">Tarsitano, Ph.D. thesis</bibRefCitation>
|
||
), there is a one-to-one correspondence between crocodilian muscle scars and the muscle scars found in well preserved theropods. In contrast, the avian pelvis and system of balance has been so modified as to be unreliable in the interpretation of theropod morphology.
|
||
</paragraph>
|
||
</subSubSection>
|
||
</treatment>
|
||
</document> |