711 lines
162 KiB
XML
711 lines
162 KiB
XML
<document ID-DOI="http://doi.org/10.5281/zenodo.3483138" ID-GBIF-Dataset="c2c78f5e-a257-4126-98ba-42e9d944da50" ID-GBIF-Taxon="190642214" ID-Zenodo-Dep="3483138" approvalRequired="1" approvalRequired_for_illustrations="1" checkinTime="1566227348899" checkinUser="jeremy" docAuthor="Carr, T. D." docDate="1999" docId="0F0287A7FFA3FFC97375FEE7FE1DF91D" docLanguage="en" docName="Carr1999TyrannosauridaeABBYY.pdf.imd" docOrigin="Journal of Vertebrate Paleontology 19 (3)" docStyle="DocumentStyle{}" docTitle="Tyrannosaurus rex Osborn 1905" docType="treatment" docVersion="28" lastPageId="19" lastPageNumber="516" masterDocId="F33BFFDFFFA8FFDA7662FFFEFFE7FFBA" masterDocTitle="Craniofacial ontogeny in Tyrannosauridae (Dinosauria, Coelurosauria)" masterLastPageNumber="520" masterPageNumber="497" pageId="11" pageNumber="508" updateTime="1645728903883" updateUser="jeremy">
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<mods:mods xmlns:mods="http://www.loc.gov/mods/v3">
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<mods:titleInfo>
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<mods:title>Craniofacial ontogeny in Tyrannosauridae (Dinosauria, Coelurosauria)</mods:title>
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</mods:titleInfo>
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<mods:name type="personal">
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<mods:role>
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<mods:roleTerm>Author</mods:roleTerm>
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</mods:role>
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<mods:namePart>Carr, T. D.</mods:namePart>
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</mods:name>
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<mods:typeOfResource>text</mods:typeOfResource>
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<mods:relatedItem type="host">
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<mods:titleInfo>
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<mods:title>Journal of Vertebrate Paleontology</mods:title>
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</mods:titleInfo>
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<mods:part>
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<mods:date>1999</mods:date>
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<mods:detail type="pubDate">
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<mods:number>1999-09-30</mods:number>
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</mods:detail>
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<mods:detail type="volume">
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<mods:number>19</mods:number>
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</mods:detail>
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<mods:detail type="issue">
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<mods:number>3</mods:number>
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</mods:detail>
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<mods:extent unit="page">
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<mods:start>497</mods:start>
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<mods:end>520</mods:end>
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</mods:extent>
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</mods:part>
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</mods:relatedItem>
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<mods:classification>journal article</mods:classification>
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<mods:identifier type="DOI">10.1080/02724634.1999.10011161</mods:identifier>
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<mods:identifier type="GBIF-Dataset">c2c78f5e-a257-4126-98ba-42e9d944da50</mods:identifier>
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<mods:identifier type="Zenodo-Dep">3372241</mods:identifier>
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</mods:mods>
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<treatment ID-DOI="http://doi.org/10.5281/zenodo.3483138" ID-GBIF-Taxon="190642214" ID-Zenodo-Dep="3483138" LSID="urn:lsid:plazi:treatment:0F0287A7FFA3FFC97375FEE7FE1DF91D" httpUri="http://treatment.plazi.org/id/0F0287A7FFA3FFC97375FEE7FE1DF91D" lastPageId="19" lastPageNumber="516" pageId="11" pageNumber="508">
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<subSubSection box="[1303,1717,281,316]" pageId="11" pageNumber="508" type="reference_group">
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<paragraph blockId="11.[1302,2360,280,1211]" box="[1303,1717,281,316]" pageId="11" pageNumber="508">
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<taxonomicName baseAuthorityName="Gilmore" baseAuthorityYear="1946" box="[1303,1717,281,316]" class="Reptilia" family="Tyrannosauridae" genus="Nanotyrannus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="11" pageNumber="508" phylum="Chordata" rank="species" species="lancensis" status="syn. nov.">Nanotyrannus lancensis</taxonomicName>
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</paragraph>
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</subSubSection>
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<subSubSection lastPageId="12" lastPageNumber="509" pageId="11" pageNumber="508" type="description">
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<paragraph blockId="11.[1302,2360,280,1211]" pageId="11" pageNumber="508">
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<materialsCitation ID-GBIF-Occurrence="3396378369" box="[1346,1565,342,378]" collectionCode="CMNH" pageId="11" pageNumber="508" specimenCode="CMNH 7541" specimenCount="1">
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<specimenCode box="[1346,1565,342,378]" pageId="11" pageNumber="508">CMNH 7541</specimenCode>
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</materialsCitation>
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, a damaged skull with lower jaws in occlusion (
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<figureCitation box="[1318,1502,384,420]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="11" pageNumber="508" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A-D</figureCitation>
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), was collected from the Hell Creek Formation of Montana in 1942 and described by C. W.
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<bibRefCitation author="Gilmore, C. W." box="[2020,2276,425,461]" journalOrPublisher="Smithsonian Miscellaneous Collections" pageId="11" pageNumber="508" pagination="1 - 19" part="106" refId="ref18815" refString="Gilmore, C. W. 1946. A new carnivorous dinosaur from the Lance Formation of Montana. Smithsonian Miscellaneous Collections 106: 1 - 19." title="A new carnivorous dinosaur from the Lance Formation of Montana" type="journal article" year="1946">Gilmore (1946)</bibRefCitation>
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in a posthumous publication.
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<materialsCitation ID-GBIF-Occurrence="3396378306" box="[1730,1944,467,503]" collectionCode="CMNH" pageId="11" pageNumber="508" specimenCode="CMNH 7541" specimenCount="1">
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<specimenCode box="[1730,1944,467,503]" pageId="11" pageNumber="508">CMNH 7541</specimenCode>
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</materialsCitation>
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was heavily restored in plaster, and Gilmore erred in his account of sutural fusion in the skull, a misinterpretation perpetuated by later workers (
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<bibRefCitation author="Russell, D. A." journalOrPublisher="National Museum of Natural Sciences Publications in Palaeontology" pageId="11" pageNumber="508" pagination="1 - 30" part="1" refId="ref19547" refString="Russell, D. A. 1970. Tyrannosaurs From the Late Cretaceous of Western Canada. National Museum of Natural Sciences Publications in Palaeontology 1: 1 - 30." title="Tyrannosaurs From the Late Cretaceous of Western Canada" type="journal article" year="1970">Russell, 1970</bibRefCitation>
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;
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<bibRefCitation author="Bakker, R. T. & M. Williams & P. J. Currie" box="[1493,1816,592,628]" journalOrPublisher="Hunteria" pageId="11" pageNumber="508" pagination="1 - 30" part="1" refId="ref18472" refString="Bakker, R. T., M. Williams, and P. J. Currie. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana. Hunteria 1: 1 - 30." title="Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana" type="journal article" year="1988">Bakker et al., 1988</bibRefCitation>
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;
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<bibRefCitation author="Paul, G. S." bookContentInfo="464 pp" box="[1836,2018,592,628]" journalOrPublisher="Simon and Schuster, New York" pageId="11" pageNumber="508" refId="ref19442" refString="Paul, G. S. 1988. Predatory Dinosaurs of the World: A Complete Illustrated Guide. Simon and Schuster, New York, 464 pp" title="Predatory Dinosaurs of the World: A Complete Illustrated Guide." type="book" year="1988">Paul, 1988</bibRefCitation>
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). In fact, there is no evidence of sutural fusion in this specimen except for fusion of the intranasal and intraparietal sutures, which is typical of Stage 1
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<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[1340,1522,717,753]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="11" pageNumber="508" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
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. Gilmore noted the similarity of the skull to the smallest specimen of
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<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[1680,1861,759,795]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="11" pageNumber="508" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
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then known (AMNH 5664); thus
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<bibRefCitation author="Gilmore, C. W." box="[1386,1632,800,836]" journalOrPublisher="Smithsonian Miscellaneous Collections" pageId="11" pageNumber="508" pagination="1 - 19" part="106" refId="ref18815" refString="Gilmore, C. W. 1946. A new carnivorous dinosaur from the Lance Formation of Montana. Smithsonian Miscellaneous Collections 106: 1 - 19." title="A new carnivorous dinosaur from the Lance Formation of Montana" type="journal article" year="1946">Gilmore (1946)</bibRefCitation>
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made
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<materialsCitation ID-GBIF-Occurrence="3396378370" box="[1745,1955,800,836]" collectionCode="CMNH" pageId="11" pageNumber="508" specimenCode="CMNH 7541" specimenCount="1">
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<specimenCode box="[1745,1955,800,836]" pageId="11" pageNumber="508">CMNH 7541</specimenCode>
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</materialsCitation>
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the holotype of the new taxon,
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<taxonomicName authorityName="Gilmore" authorityYear="1946" box="[1422,1805,842,878]" class="Reptilia" family="Tyrannosauridae" genus="Gorgosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="11" pageNumber="508" phylum="Chordata" rank="species" species="lancensis">Gorgosaurus lancensis</taxonomicName>
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.
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</paragraph>
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<paragraph blockId="11.[1302,2360,280,1211]" pageId="11" pageNumber="508">
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In his review of tyrannosaurids from western Canada,
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<bibRefCitation author="Russell, D. A." journalOrPublisher="National Museum of Natural Sciences Publications in Palaeontology" pageId="11" pageNumber="508" pagination="1 - 30" part="1" refId="ref19547" refString="Russell, D. A. 1970. Tyrannosaurs From the Late Cretaceous of Western Canada. National Museum of Natural Sciences Publications in Palaeontology 1: 1 - 30." title="Tyrannosaurs From the Late Cretaceous of Western Canada" type="journal article" year="1970">Russell (1970)</bibRefCitation>
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referred
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<taxonomicName authorityName="Gilmore" authorityYear="1946" box="[1578,1831,925,961]" class="Reptilia" family="Tyrannosauridae" genus="Gorgosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="11" pageNumber="508" phylum="Chordata" rank="species" species="lancensis">”G”. lancensis</taxonomicName>
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to
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<taxonomicName authorityName="Osborn" authorityYear="1905" box="[1892,2127,925,961]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="11" pageNumber="508" phylum="Chordata" rank="genus">Albertosaurus</taxonomicName>
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and accepted Gilmore’s interpretation of sutural fusion and its indication of relative maturity. Later,
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<bibRefCitation author="Bakker, R. T. & M. Williams & P. J. Currie" box="[1705,2087,1009,1045]" journalOrPublisher="Hunteria" pageId="11" pageNumber="508" pagination="1 - 30" part="1" refId="ref18472" refString="Bakker, R. T., M. Williams, and P. J. Currie. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana. Hunteria 1: 1 - 30." title="Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana" type="journal article" year="1988">Bakker et al. (1988:17)</bibRefCitation>
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proposed a new genus of dwarf tyrannosaurid,
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<taxonomicName authorityName="Bakker, Williams & Currie" authorityYear="1988" box="[1819,2052,1050,1086]" class="Reptilia" family="Tyrannosauridae" genus="Nanotyrannus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="11" pageNumber="508" phylum="Chordata" rank="genus">Nanotyrannus</taxonomicName>
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, for “
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<taxonomicName authorityName="Gilmore" authorityYear="1946" class="Reptilia" family="Tyrannosauridae" genus="Gorgosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="11" pageNumber="508" phylum="Chordata" rank="species" species="lancensis">G.” lancensis</taxonomicName>
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, offering sutural fusion between the frontal and prefrontal and between the parietal and frontal as the criteria for the adult nature of the specimen.
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</paragraph>
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<paragraph blockId="11.[1300,2359,1260,3106]" box="[1306,1908,1260,1295]" pageId="11" pageNumber="508">
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Relative Maturity of
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<materialsCitation ID-GBIF-Occurrence="3396378303" box="[1686,1908,1260,1295]" collectionCode="CMNH" pageId="11" pageNumber="508" specimenCode="CMNH 7541" specimenCount="1">
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<specimenCode box="[1686,1908,1260,1295]" pageId="11" pageNumber="508">CMNH 7541</specimenCode>
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</materialsCitation>
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</paragraph>
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<paragraph blockId="11.[1300,2359,1260,3106]" pageId="11" pageNumber="508">
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The presence of striated cortical bone was demonstrated by
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<bibRefCitation author="Bennett, S. C." box="[1306,1558,1363,1399]" journalOrPublisher="Paleobiology" pageId="11" pageNumber="508" pagination="92 - 106" part="19" refId="ref18594" refString="Bennett, S. C. 1993. The Ontogeny of Pteranodon and Other Pterosaurs. Paleobiology 19: 92 - 106" title="The Ontogeny of Pteranodon and Other Pterosaurs" type="journal article" year="1993">Bennett (1993)</bibRefCitation>
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and
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<bibRefCitation author="Sampson, S. D." bookContentInfo="299 pp" box="[1655,1928,1363,1399]" journalOrPublisher="University of Toronto, Toronto" pageId="11" pageNumber="508" refId="ref19609" refString="Sampson, S. D. 1993. Cranial Ornamentations in Ceratopsid Dinosaurs: Systematic, Behavioral, and Evolutionary Implications. Ph. D. dissertation, University of Toronto, Toronto, 299 pp" title="Cranial Ornamentations in Ceratopsid Dinosaurs: Systematic, Behavioral, and Evolutionary Implications" type="book" year="1993">Sampson (1993)</bibRefCitation>
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to distinguish immature, fast-growing individuals from mature specimens for pterosaurs and centrosaurine ceratopsids, respectively. Immature bone grain is lost with increase in size and development of ontogenetic characters, thus providing a crude measure of relative maturity among reptiles.
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</paragraph>
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<paragraph blockId="11.[1300,2359,1260,3106]" pageId="11" pageNumber="508">
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On
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<materialsCitation ID-GBIF-Occurrence="3396378351" box="[1413,1633,1612,1648]" collectionCode="CMNH" pageId="11" pageNumber="508" specimenCode="CMNH 7541" specimenCount="1">
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<specimenCode box="[1413,1633,1612,1648]" pageId="11" pageNumber="508">CMNH 7541</specimenCode>
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</materialsCitation>
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, immature bone grain is present on the antorbital fossa of the maxilla (
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<figureCitation box="[1798,1927,1654,1690]" captionStart="FIGURE 7" captionStartId="17.[197,327,1679,1711]" captionTargetBox="[210,2334,264,1638]" captionTargetPageId="17" captionText="FIGURE 7. Immature bone grain on the lateral surface of the antorbital fossa of the maxilla (A; reversed), jugal (B), surangular (C), and the dorsal surface of the nasal and frontal (D) of an early ontogeny Tyrannosaurus rex (CMNH 7541). Skull length is 572 mm." figureDoi="http://doi.org/10.5281/zenodo.3958115" httpUri="https://zenodo.org/record/3958115/files/figure.png" pageId="11" pageNumber="508" targetBox="[210,2334,264,1638]" targetPageId="17">Fig. 7A</figureCitation>
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) and lacrimal, lateral surface of the vomer, dentary, surangular (
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<figureCitation box="[1983,2115,1695,1731]" captionStart="FIGURE 7" captionStartId="17.[197,327,1679,1711]" captionTargetBox="[210,2334,264,1638]" captionTargetPageId="17" captionText="FIGURE 7. Immature bone grain on the lateral surface of the antorbital fossa of the maxilla (A; reversed), jugal (B), surangular (C), and the dorsal surface of the nasal and frontal (D) of an early ontogeny Tyrannosaurus rex (CMNH 7541). Skull length is 572 mm." figureDoi="http://doi.org/10.5281/zenodo.3958115" httpUri="https://zenodo.org/record/3958115/files/figure.png" pageId="11" pageNumber="508" targetBox="[210,2334,264,1638]" targetPageId="17">Fig. 7C</figureCitation>
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), angular, palatine, jugal (
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<figureCitation box="[1525,1659,1738,1774]" captionStart="FIGURE 7" captionStartId="17.[197,327,1679,1711]" captionTargetBox="[210,2334,264,1638]" captionTargetPageId="17" captionText="FIGURE 7. Immature bone grain on the lateral surface of the antorbital fossa of the maxilla (A; reversed), jugal (B), surangular (C), and the dorsal surface of the nasal and frontal (D) of an early ontogeny Tyrannosaurus rex (CMNH 7541). Skull length is 572 mm." figureDoi="http://doi.org/10.5281/zenodo.3958115" httpUri="https://zenodo.org/record/3958115/files/figure.png" pageId="11" pageNumber="508" targetBox="[210,2334,264,1638]" targetPageId="17">Fig. 7B</figureCitation>
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), ventral process of the maxilla, quadratojugal process of the squamosal, squamosal ramus of the postorbital, rostral surface of the supraoccipital crest of the parietal, medial surface of the prearticular and splenial, caudal margin of the quadratojugal, caudal surface of the quadrate, and dorsal surface of the frontal and nasals (
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<figureCitation box="[1874,2007,1945,1981]" captionStart="FIGURE 7" captionStartId="17.[197,327,1679,1711]" captionTargetBox="[210,2334,264,1638]" captionTargetPageId="17" captionText="FIGURE 7. Immature bone grain on the lateral surface of the antorbital fossa of the maxilla (A; reversed), jugal (B), surangular (C), and the dorsal surface of the nasal and frontal (D) of an early ontogeny Tyrannosaurus rex (CMNH 7541). Skull length is 572 mm." figureDoi="http://doi.org/10.5281/zenodo.3958115" httpUri="https://zenodo.org/record/3958115/files/figure.png" pageId="11" pageNumber="508" targetBox="[210,2334,264,1638]" targetPageId="17">Fig. 7D</figureCitation>
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).
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</paragraph>
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<paragraph blockId="11.[1300,2359,1260,3106]" pageId="11" pageNumber="508">
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In addition, none of the “fusions” (frontal-frontal, frontalprefrontal, nasal-maxilla, nasal-lacrimal, nasal-prefrontal, premaxilla-maxilla, maxilla-lacrimal, maxilla-nasal) claimed by
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<bibRefCitation author="Gilmore, C. W." box="[1305,1565,2113,2149]" journalOrPublisher="Smithsonian Miscellaneous Collections" pageId="11" pageNumber="508" pagination="1 - 19" part="106" refId="ref18815" refString="Gilmore, C. W. 1946. A new carnivorous dinosaur from the Lance Formation of Montana. Smithsonian Miscellaneous Collections 106: 1 - 19." title="A new carnivorous dinosaur from the Lance Formation of Montana" type="journal article" year="1946">Gilmore (1946)</bibRefCitation>
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or by
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<bibRefCitation author="Bakker, R. T. & M. Williams & P. J. Currie" box="[1694,2039,2113,2149]" journalOrPublisher="Hunteria" pageId="11" pageNumber="508" pagination="1 - 30" part="1" refId="ref18472" refString="Bakker, R. T., M. Williams, and P. J. Currie. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana. Hunteria 1: 1 - 30." title="Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana" type="journal article" year="1988">Bakker et al. (1988)</bibRefCitation>
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actually occurs in
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<materialsCitation ID-GBIF-Occurrence="3396378316" box="[1305,1530,2154,2190]" collectionCode="CMNH" pageId="11" pageNumber="508" specimenCode="CMNH 7541" specimenCount="1">
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<specimenCode box="[1305,1530,2154,2190]" pageId="11" pageNumber="508">CMNH 7541</specimenCode>
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</materialsCitation>
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. In fact, none of the fusions enumerated above occurs in any tyrannosaurid skulls externally (pers. obs.), except suture closure around the prefrontal varies in some
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<taxonomicName authorityName="Osborn" authorityYear="1905" box="[2163,2257,2238,2274]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="11" pageNumber="508" phylum="Chordata" rank="species" species="rex">T. rex</taxonomicName>
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(Brochu, pers. comm.). Therefore, I regard
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<materialsCitation ID-GBIF-Occurrence="3396378319" box="[1959,2172,2279,2315]" collectionCode="CMNH" pageId="11" pageNumber="508" specimenCode="CMNH 7541" specimenCount="1">
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<specimenCode box="[1959,2172,2279,2315]" pageId="11" pageNumber="508">CMNH 7541</specimenCode>
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</materialsCitation>
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as a Stage 1 specimen on the basis of cortical bone texture, a conclusion consistent with its size (skull length 572 mm). Also,
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<materialsCitation ID-GBIF-Occurrence="3396378383" collectionCode="CMNH" pageId="11" pageNumber="508" specimenCode="CMNH 7541" specimenCount="1">
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<specimenCode pageId="11" pageNumber="508">CMNH 7541</specimenCode>
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</materialsCitation>
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exhibits the characters typical of Stage 1 specimens of
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<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="11" pageNumber="508" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
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(see
|
||
<figureCitation box="[1524,1721,2445,2481]" captionStart="APPENDIX 1" captionStartId="21.[196,376,577,609]" captionTargetBox="[194,2340,835,3026]" captionTargetPageId="21" captionText="APPENDIX 1. A genus-level comparison of tyrannosaurids: the growth changes of Albertosaurus libratus compared with the homologous characters in Daspletosaurus torosus and Tyrannosaurus rex. Abbreviations: aofen, antorbital fenestra; aofo, antorbital fossa; artic, articular; basis pn for, basisphenoid pneumatic foramen; cdrsl, caudodorsal; cnflt, confluent; cnvx, convex; corn, cornual; dtf, dorsotemporal fossa; fen, fenestra; hrz, horizontal; intramnd, intramandibular; ltfen, laterotemporal fenestra; M. add mand ext, Musculus adductor mandibular pars externus; max, maxilla; occ con, occipital condyle; pn, pneumatic; po, postorbital; pr, process; qj, quadratojugal; rd, rostrodorsal; rv, rostroventral; sbn, subnarial; shllw, shallow; smth, smooth; sq, squamosal; surf, surface." figureDoi="http://doi.org/10.5281/zenodo.3958119" httpUri="https://zenodo.org/record/3958119/files/figure.png" pageId="11" pageNumber="508">
|
||
<tableCitation box="[1524,1721,2445,2481]" captionStart="APPENDIX 1" captionStartId="21.[196,376,577,609]" captionTargetBox="[194,2340,835,3026]" captionTargetPageId="21" captionText="APPENDIX 1. A genus-level comparison of tyrannosaurids: the growth changes of Albertosaurus libratus compared with the homologous characters in Daspletosaurus torosus and Tyrannosaurus rex. Abbreviations: aofen, antorbital fenestra; aofo, antorbital fossa; artic, articular; basis pn for, basisphenoid pneumatic foramen; cdrsl, caudodorsal; cnflt, confluent; cnvx, convex; corn, cornual; dtf, dorsotemporal fossa; fen, fenestra; hrz, horizontal; intramnd, intramandibular; ltfen, laterotemporal fenestra; M. add mand ext, Musculus adductor mandibular pars externus; max, maxilla; occ con, occipital condyle; pn, pneumatic; po, postorbital; pr, process; qj, quadratojugal; rd, rostrodorsal; rv, rostroventral; sbn, subnarial; shllw, shallow; smth, smooth; sq, squamosal; surf, surface." httpUri="http://table.plazi.org/id/D3D46639FFBDFFCF76A6FDBFFBA4FCA8" pageId="11" pageNumber="508" tableUuid="D3D46639FFBDFFCF76A6FDBFFBA4FCA8">Appendix 1</tableCitation>
|
||
</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="11.[1300,2359,1260,3106]" pageId="11" pageNumber="508">
|
||
Premaxilla—In rostral view, the premaxillae are narrow and their lateral margins are concave at the base of the maxillary processes, and the alveolar region is shallow (
|
||
<figureCitation box="[2081,2199,2570,2606]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="11" pageNumber="508" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8J</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="11.[1300,2359,1260,3106]" pageId="11" pageNumber="508">
|
||
Maxilla—The maxillae of
|
||
<materialsCitation ID-GBIF-Occurrence="3396378313" box="[1820,2040,2613,2649]" collectionCode="CMNH" pageId="11" pageNumber="508" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1820,2040,2613,2649]" pageId="11" pageNumber="508">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
are laterally flattened, the alveolar process is shallow, the first tooth is incisiform, and the remaining teeth are labiolingually narrow (
|
||
<figureCitation captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="11" pageNumber="508" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A, D</figureCitation>
|
||
). Also, the ventrolateral rim of the ventral jugal process is not breached by the caudalmost neurovascular sulcus of the ventral row of foramina (
|
||
<figureCitation box="[1727,1859,2820,2856]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="11" pageNumber="508" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
). The lateral surface does not extend caudally over the rostral margin of the antorbital fossa (
|
||
<figureCitation box="[1314,1449,2904,2940]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="11" pageNumber="508" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
), the promaxillary fenestra is dorsoventrally elongate and not recessed (
|
||
<figureCitation box="[1599,1731,2945,2981]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="11" pageNumber="508" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
), the antorbital fenestra is longer than high, and the small maxillary fenestra is midway between the rostral margins of the antorbital fossa and restored fenestra (
|
||
<figureCitation captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="11" pageNumber="508" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Nasal—In
|
||
<materialsCitation ID-GBIF-Occurrence="3396378311" box="[429,657,281,317]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[429,657,281,317]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
, the nasals are smooth with low transverse and fine rostrocaudal ridges (
|
||
<figureCitation box="[902,1101,323,359]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A, B</figureCitation>
|
||
). In the smallest Stage 1 specimen of
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[751,941,365,401]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
examined (TMP 86.144.1), the rugose texture typical of mature specimens is present. The condition in
|
||
<materialsCitation ID-GBIF-Occurrence="3396378301" box="[620,833,449,485]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[620,833,449,485]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
might represent individual, ontogenetic, or taxonomic variation.
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Lacrimal—In
|
||
<materialsCitation ID-GBIF-Occurrence="3396378329" box="[491,709,533,569]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[491,709,533,569]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
the rostral margin of the rostroventral lamina is concave to straight and the contact of the lamina with the jugal exceeds that of the ventral ramus as in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[340,525,660,696]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
(
|
||
<figureCitation box="[556,696,660,696]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
). Also, there is no evidence of fusion between the ventral margins of the medial and lateral processes of the rostral ramus.
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Jugal—As in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[633,818,786,822]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the maxillary ramus of
|
||
<materialsCitation ID-GBIF-Occurrence="3396378362" box="[191,408,828,864]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[191,408,828,864]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
is dorsoventrally shallow and tapered (
|
||
<figureCitation box="[1094,1227,828,864]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
). The jugal pneumatic recess is a rostrally-restricted slit (
|
||
<figureCitation captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
), the postorbital articular surface approaches the orbit floor (
|
||
<figureCitation box="[203,335,954,990]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
), the region ventral to the postorbital ramus is convex (
|
||
<figureCitation box="[203,334,996,1032]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
), the caudal margin of the postorbital ramus is convex at midheight, and the caudal rim of the lacrimal articular surface is subvertical (
|
||
<figureCitation box="[439,573,1080,1116]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Postorbital—As in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[704,882,1122,1158]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the laterodorsal margin is not everted medially into the dorsotemporal fenestra (
|
||
<figureCitation captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A, B</figureCitation>
|
||
). There is no postorbital cornual process or suborbital prong (
|
||
<figureCitation box="[309,440,1248,1284]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
); the former is represented by a textured surface. Unlike
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[314,494,1290,1326]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the rostral and caudal margins of the jugal process taper rostroventrally (
|
||
<figureCitation box="[691,826,1333,1369]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Prefrontal—As in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[713,896,1374,1410]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
specimens, the prefrontal is situated at the rostrolateral margin of the frontal, bounded caudally by a triangular, tab-like process from the frontal to separate it from the lacrimal caudolaterally (
|
||
<figureCitation box="[1098,1225,1500,1536]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6B</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Frontal—As in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[667,852,1543,1579]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the lacrimal notch in
|
||
<materialsCitation ID-GBIF-Occurrence="3396378377" box="[189,407,1585,1621]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[189,407,1585,1621]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
is elongate and narrow in dorsal view, the prefrontal notch is rostrocaudally stout in dorsal view, and the paired frontals are longer than wide (
|
||
<figureCitation box="[808,937,1669,1705]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6B</figureCitation>
|
||
). Further evidence of the immature nature of the specimen is provided by the relatively elongate orbital margin (11 mm) and the shallow dorsotemporal fossa, which has a barely discernible rostral margin (
|
||
<figureCitation box="[203,332,1840,1876]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6B</figureCitation>
|
||
). Unlike Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[623,801,1840,1876]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the frontals appear to rise to meet each other along the midline rostral to the dorsotemporal fossa (
|
||
<figureCitation box="[403,535,1925,1961]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6B</figureCitation>
|
||
); however, cracks suggest this may be an artifact of dorsoventral crushing.
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Parietal—In
|
||
<materialsCitation ID-GBIF-Occurrence="3396378317" box="[459,671,2010,2046]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[459,671,2010,2046]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
the delicate nuchal crest is low in caudal view (
|
||
<figureCitation box="[414,544,2052,2088]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6C</figureCitation>
|
||
). Its dorsal margin is rostrally everted and the laterodorsal margin is convex in frontal section (
|
||
<figureCitation captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A, B</figureCitation>
|
||
). Unlike Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[519,697,2137,2173]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the sagittal crest in lateral view is tall and blade-like.
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Ectopterygoid—In
|
||
<materialsCitation ID-GBIF-Occurrence="3396378376" box="[570,789,2222,2258]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[570,789,2222,2258]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
, unlike Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[1061,1238,2222,2258]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the ectopterygoid is inflated, except for the jugal ramus (
|
||
<figureCitation captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6D</figureCitation>
|
||
). As in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[543,726,2307,2343]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the muscle scar on the jugal ramus is caudolaterally positioned.
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Supraoccipital—As in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[759,936,2392,2428]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the dorsal process of the supraoccipital of
|
||
<materialsCitation ID-GBIF-Occurrence="3396378338" box="[599,814,2435,2471]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[599,814,2435,2471]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
is narrow and has a horizontal dorsal border with flange-like rostrolateral edges (
|
||
<figureCitation captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6C</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Basioccipital—As in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[760,943,2561,2597]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the ventrolateral margins of the occipital condyle taper toward each other ventrally and the caudoventral condylar surface is flattened (
|
||
<figureCitation captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6C</figureCitation>
|
||
). The ventral surface of the basituberal web is flat and arched in caudal view (
|
||
<figureCitation box="[609,746,2732,2768]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6C</figureCitation>
|
||
). The median portion of the basioccipital is concave between the laminae and the bone is strongly excavated caudolaterally by the subcondylar recess (
|
||
<figureCitation box="[205,336,2860,2896]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6C</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" pageId="12" pageNumber="509">
|
||
Parabasisphenoid—As in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[820,997,2903,2939]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, the pneumatic foramina in the basisphenoid are small and situated ventrally and the oval scar is smooth and lateroventrally oriented (
|
||
<figureCitation captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6C, D</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[189,1251,281,3108]" lastBlockId="12.[1300,2361,280,742]" pageId="12" pageNumber="509">
|
||
Dentary—As in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[670,852,3071,3107]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
the dentary of
|
||
<materialsCitation ID-GBIF-Occurrence="3396378354" box="[1128,1377,280,3108]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1128,1377,280,3108]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
is relatively shallow in lateral view and narrow in ventral view (
|
||
<figureCitation box="[1407,1594,323,359]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6A, D</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[1300,2361,280,742]" pageId="12" pageNumber="509">
|
||
Surangular—In
|
||
<materialsCitation ID-GBIF-Occurrence="3396378337" box="[1632,1846,365,401]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1632,1846,365,401]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
the surangular is shallow and the surangular shelf is horizontal (
|
||
<figureCitation box="[1882,2014,408,444]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6C</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[1300,2361,280,742]" pageId="12" pageNumber="509">
|
||
Prearticular—As in Stage 1
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[1856,2040,450,486]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
the dorsal margin of the caudal ramus of the prearticular is restricted caudally (
|
||
<figureCitation box="[1313,1447,535,571]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6D</figureCitation>
|
||
), the caudal ramus is shallow with parallel dorsal and ventral margins (
|
||
<figureCitation box="[1584,1716,578,614]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6D</figureCitation>
|
||
), the rostral lamina is slightly expanded and its parallel margins converge to a point distally (
|
||
<figureCitation captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6D</figureCitation>
|
||
), and the caudodorsal surface of the rostral lamina is smooth (
|
||
<figureCitation box="[1313,1447,706,742]" captionStart="FIGURE 6" captionStartId="15.[199,331,2967,2999]" captionTargetBox="[238,2304,264,2928]" captionTargetPageId="15" captionText="FIGURE 6. Restored skull with occluded jaws of a Stage 1 Tyrannosaurus rex (CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na, FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer." figureDoi="http://doi.org/10.5281/zenodo.4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" pageId="12" pageNumber="509" targetBox="[238,2304,264,2928]" targetPageId="15">Fig. 6D</figureCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[1686,1972,809,845]" box="[1686,1972,809,845]" pageId="12" pageNumber="509">CONCLUSIONS</paragraph>
|
||
<paragraph blockId="12.[1299,1791,890,926]" box="[1299,1790,891,926]" pageId="12" pageNumber="509">
|
||
Immaturity of
|
||
<materialsCitation ID-GBIF-Occurrence="3396378342" box="[1568,1790,891,926]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1568,1790,891,926]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
</paragraph>
|
||
<paragraph blockId="12.[1295,2365,972,3108]" pageId="12" pageNumber="509">
|
||
The morphological structure of
|
||
<materialsCitation ID-GBIF-Occurrence="3396378343" box="[1868,2080,972,1008]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1868,2080,972,1008]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
agrees with that of Stage 1 specimens of
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[1745,1930,1015,1051]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
and displays no mature features. The weight of evidence indicates that
|
||
<materialsCitation ID-GBIF-Occurrence="3396378379" box="[2099,2314,1057,1093]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[2099,2314,1057,1093]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
is juvenile. The presence of immature bone grain (
|
||
<figureCitation box="[2153,2260,1100,1136]" captionStart="FIGURE 7" captionStartId="17.[197,327,1679,1711]" captionTargetBox="[210,2334,264,1638]" captionTargetPageId="17" captionText="FIGURE 7. Immature bone grain on the lateral surface of the antorbital fossa of the maxilla (A; reversed), jugal (B), surangular (C), and the dorsal surface of the nasal and frontal (D) of an early ontogeny Tyrannosaurus rex (CMNH 7541). Skull length is 572 mm." figureDoi="http://doi.org/10.5281/zenodo.3958115" httpUri="https://zenodo.org/record/3958115/files/figure.png" pageId="12" pageNumber="509" targetBox="[210,2334,264,1638]" targetPageId="17">Fig. 7</figureCitation>
|
||
) precludes the specimen from representing an adult pygmy tyrannosaurid.
|
||
</paragraph>
|
||
<paragraph blockId="12.[1295,2365,972,3108]" pageId="12" pageNumber="509">
|
||
Status of Nanotyrannus—
|
||
<bibRefCitation author="Rozhdestvensky, A. K." box="[1799,2193,1227,1263]" journalOrPublisher="Palaeontological Journal" pageId="12" pageNumber="509" pagination="95 - 109" part="3" refId="ref19519" refString="Rozhdestvensky, A. K. 1965. Growth changes in Asian dinosaurs and some problems of their taxonomy. Palaeontological Journal 3: 95 - 109." title="Growth changes in Asian dinosaurs and some problems of their taxonomy" type="journal article" year="1965">Rozhdestvensky (1965)</bibRefCitation>
|
||
first suggested that
|
||
<materialsCitation ID-GBIF-Occurrence="3396378339" box="[1503,1722,1269,1305]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1503,1722,1269,1305]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
might be a juvenile
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="rex">Tyrannosaurus rex</taxonomicName>
|
||
, based on his observations of
|
||
<taxonomicName authorityName="Maleev" authorityYear="1955" box="[1871,2026,1311,1347]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="bataar">T. bataar</taxonomicName>
|
||
, in which juveniles vary in “slightly different proportions than in the large specimens, as we should expect if they are of different (ontogenetic) ages” (
|
||
<bibRefCitation author="Rozhdestvensky, A. K." box="[1421,1876,1440,1476]" journalOrPublisher="Palaeontological Journal" pageId="12" pageNumber="509" pagination="95 - 109" part="3" refId="ref19519" refString="Rozhdestvensky, A. K. 1965. Growth changes in Asian dinosaurs and some problems of their taxonomy. Palaeontological Journal 3: 95 - 109." title="Growth changes in Asian dinosaurs and some problems of their taxonomy" type="journal article" year="1965">Rozhdestvensky, 1965:106</bibRefCitation>
|
||
).
|
||
</paragraph>
|
||
<paragraph blockId="12.[1295,2365,972,3108]" pageId="12" pageNumber="509">
|
||
<bibRefCitation author="Carpenter, K." box="[1339,1623,1483,1519]" editor="N. Mateer & P. J. Chen" journalOrPublisher="China Ocean Press, Beijing" pageId="12" pageNumber="509" pagination="250 - 268" refId="ref18651" refString="Carpenter, K. 1992. Tyrannosaurids (Dinosauria) of Asia and North America; pp. 250 - 268 in N. Mateer and P. J. Chen (eds.), Aspects of Nonmarine Cretaceous Geology. China Ocean Press, Beijing" title="Tyrannosaurids (Dinosauria) of Asia and North America" type="book chapter" volumeTitle="Aspects of Nonmarine Cretaceous Geology" year="1992">Carpenter (1992)</bibRefCitation>
|
||
also suggested that
|
||
<materialsCitation ID-GBIF-Occurrence="3396378330" box="[1974,2189,1483,1519]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1974,2189,1483,1519]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
might be an immature specimen of
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[1754,1856,1526,1562]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="rex">T. rex</taxonomicName>
|
||
on the basis of its long and low snout, separate nasals and frontal, circular orbit, and rostrocaudally oval margin of the antorbital fenestra. Carpenter was uncertain of the significance of the last feature, owing to its acute rostral margin relative to that in immature specimens of
|
||
<taxonomicName authorityName="Maleev" authorityYear="1955" box="[1351,1510,1740,1776]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="bataar">T. bataar</taxonomicName>
|
||
. In fact, on both sides, this region is absent and restored in plaster in
|
||
<materialsCitation ID-GBIF-Occurrence="3396378331" box="[1655,1875,1784,1820]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1655,1875,1784,1820]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
. Carpenter’s suggestion concerning ontogenetically variable features, except for the nasalfrontal contact, is consistent with the observations reported here. He noted two features that united the specimen with
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="genus">Tyrannosaurus</taxonomicName>
|
||
: considerable lateral constriction of the snout, and a dorsally broad temporal region (
|
||
<figureCitation box="[1888,2078,1999,2035]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8C, D</figureCitation>
|
||
). However,
|
||
<bibRefCitation author="Carpenter, K." editor="N. Mateer & P. J. Chen" journalOrPublisher="China Ocean Press, Beijing" pageId="12" pageNumber="509" pagination="250 - 268" refId="ref18651" refString="Carpenter, K. 1992. Tyrannosaurids (Dinosauria) of Asia and North America; pp. 250 - 268 in N. Mateer and P. J. Chen (eds.), Aspects of Nonmarine Cretaceous Geology. China Ocean Press, Beijing" title="Tyrannosaurids (Dinosauria) of Asia and North America" type="book chapter" volumeTitle="Aspects of Nonmarine Cretaceous Geology" year="1992">Carpenter (1992:528)</bibRefCitation>
|
||
tentatively accepted Russell’s identification of
|
||
<materialsCitation ID-GBIF-Occurrence="3396378327" box="[1299,1513,2085,2121]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1299,1513,2085,2121]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
as?
|
||
<taxonomicName baseAuthorityName="Gilmore" baseAuthorityYear="1946" box="[1598,1803,2085,2121]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="lancensis">A. lancensis</taxonomicName>
|
||
.
|
||
</paragraph>
|
||
<paragraph blockId="12.[1295,2365,972,3108]" pageId="12" pageNumber="509">
|
||
<materialsCitation ID-GBIF-Occurrence="3396378358" box="[1340,1568,2127,2163]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1340,1568,2127,2163]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
, and specimens referred to
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[2070,2174,2127,2163]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="rex">T. rex</taxonomicName>
|
||
, share the following characters: (1) nasal processes of the premaxillae tightly appressed throughout their entire length (
|
||
<figureCitation box="[2120,2277,2213,2249]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8I, J</figureCitation>
|
||
); (2) restricted exposure of the jugal within the antorbital fenestra (
|
||
<figureCitation box="[1313,1493,2299,2335]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8E, F</figureCitation>
|
||
); (3) antorbital fossa reaches the nasal suture caudodorsally (
|
||
<figureCitation box="[1501,1678,2342,2378]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8E, F</figureCitation>
|
||
); (4) transversely broad jugal pneumatic recess (
|
||
<figureCitation box="[1428,1613,2385,2421]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8C, D</figureCitation>
|
||
); (5) elongate frontal sagittal crest (
|
||
<figureCitation captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8C, D</figureCitation>
|
||
); (6) strongly divergent and short basal tubers (
|
||
<figureCitation box="[2151,2340,2428,2464]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8G, H</figureCitation>
|
||
); (7) rostroventrally-oriented caudal occipital plate (
|
||
<figureCitation box="[2154,2340,2470,2506]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8A, B</figureCitation>
|
||
); (8) shallow subcondylar recess (
|
||
<figureCitation box="[1840,2026,2514,2550]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8G, H</figureCitation>
|
||
); (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess (
|
||
<figureCitation box="[1510,1794,2599,2635]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8A, B, G, H</figureCitation>
|
||
); (10) inflated ectopterygoid (
|
||
<figureCitation captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8A, B</figureCitation>
|
||
); (11) strongly convex rostral plate of the surangular (
|
||
<figureCitation box="[1313,1486,2685,2721]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8E, F</figureCitation>
|
||
); (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids (
|
||
<figureCitation box="[1970,2153,2728,2764]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8C, D</figureCitation>
|
||
) (
|
||
<bibRefCitation author="Carpenter, K." editor="N. Mateer & P. J. Chen" journalOrPublisher="China Ocean Press, Beijing" pageId="12" pageNumber="509" pagination="250 - 268" refId="ref18651" refString="Carpenter, K. 1992. Tyrannosaurids (Dinosauria) of Asia and North America; pp. 250 - 268 in N. Mateer and P. J. Chen (eds.), Aspects of Nonmarine Cretaceous Geology. China Ocean Press, Beijing" title="Tyrannosaurids (Dinosauria) of Asia and North America" type="book chapter" volumeTitle="Aspects of Nonmarine Cretaceous Geology" year="1992">Carpenter, 1992</bibRefCitation>
|
||
); and (13) deep mandible relative to other tyrannosaurids (
|
||
<figureCitation box="[1313,1491,2814,2850]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="12" pageNumber="509" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8E, F</figureCitation>
|
||
). Given the low number of specimens of
|
||
<taxonomicName authorityName="Maleev" authorityYear="1955" box="[2207,2362,2814,2850]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="bataar">T. bataar</taxonomicName>
|
||
examined first-hand for this study, it is conceivable that some of these characters may be generic synapomorphies. Based on the close morphological similarities between the skull of
|
||
<materialsCitation ID-GBIF-Occurrence="3396378308" box="[1301,1517,2985,3021]" collectionCode="CMNH" pageId="12" pageNumber="509" specimenCode="CMNH 7541" specimenCount="1">
|
||
<specimenCode box="[1301,1517,2985,3021]" pageId="12" pageNumber="509">CMNH 7541</specimenCode>
|
||
</materialsCitation>
|
||
and large
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[1711,1810,2985,3021]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="rex">T. rex</taxonomicName>
|
||
skulls,
|
||
</paragraph>
|
||
</subSubSection>
|
||
<subSubSection pageId="12" pageNumber="509" type="reference_group">
|
||
<paragraph blockId="12.[1295,2365,972,3108]" pageId="12" pageNumber="509">
|
||
I thus consider
|
||
<treatmentCitation ID-DOI="http://doi.org/10.5281/zenodo.3483102" ID-Zenodo-Dep="3483102" authorityName="Bakker et al." authorityYear="1988" httpUri="http://treatment.plazi.org/id/03A1879DFFD0FFE95E7FF664FEA6A618" pageId="12" pageNumber="509" treatmentCitationLabel="synonym">
|
||
<taxonomicName baseAuthorityName="Gilmore" baseAuthorityYear="1946" class="Reptilia" family="Tyrannosauridae" genus="Nanotyrannus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="lancensis" status="syn. nov.">
|
||
Nanotyrannus lancensis
|
||
<bibRefCitation author="Bakker, R. T. & M. Williams & P. J. Currie" box="[1575,1885,3028,3064]" journalOrPublisher="Hunteria" pageId="12" pageNumber="509" pagination="1 - 30" part="1" refId="ref18472" refString="Bakker, R. T., M. Williams, and P. J. Currie. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana. Hunteria 1: 1 - 30." title="Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana" type="journal article" year="1988">Bakker et al., 1988</bibRefCitation>
|
||
a
|
||
</taxonomicName>
|
||
<treatmentCitationLabel box="[1927,2363,3028,3064]" pageId="12" pageNumber="509">subjective junior synonym</treatmentCitationLabel>
|
||
of
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[1353,1911,3071,3108]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="12" pageNumber="509" phylum="Chordata" rank="species" species="rex">
|
||
Tyrannosaurus rex
|
||
<bibRefCitation author="Osborn, H. F." box="[1681,1911,3072,3108]" journalOrPublisher="Bulletin of the American Museum of Natural History" pageId="12" pageNumber="509" pagination="259 - 265" part="21" refId="ref19390" refString="Osborn, H. F. 1905. Tyrannosaurus and other Cretaceous carnivorous dinosaurs. Bulletin of the American Museum of Natural History 21: 259 - 265." title="Tyrannosaurus and other Cretaceous carnivorous dinosaurs" type="journal article" year="1905">Osborn, 1905</bibRefCitation>
|
||
</taxonomicName>
|
||
.
|
||
</treatmentCitation>
|
||
</paragraph>
|
||
</subSubSection>
|
||
<caption ID-DOI="http://doi.org/10.5281/zenodo.4749568" ID-Zenodo-Dep="4749568" httpUri="https://zenodo.org/record/4749568/files/figure.png" pageId="13" pageNumber="510" startId="13.[199,329,2831,2863]" targetBox="[285,2261,281,2791]" targetPageId="13">
|
||
<paragraph blockId="13.[198,2355,2828,2902]" pageId="13" pageNumber="510">
|
||
FIGURE 5. Composite (AMNH 5664, CMN 11315, ROM 1247, TMP 91.36.500, USNM 12815) early ontogeny (large Stage 1) skull and jaw of
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[240,571,2868,2900]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="13" pageNumber="510" phylum="Chordata" rank="species" species="libratus">Albertosaurus libratus</taxonomicName>
|
||
in lateral (A, B) and dorsal (C) views. Skull length approximately 750 mm.
|
||
</paragraph>
|
||
</caption>
|
||
<caption ID-DOI="http://doi.org/10.5281/zenodo.4749455" ID-Zenodo-Dep="4749455" httpUri="https://zenodo.org/record/4749455/files/figure.png" lastPageId="16" lastPageNumber="513" pageId="15" pageNumber="512" startId="15.[199,331,2967,2999]" targetBox="[238,2304,264,2928]" targetPageId="15">
|
||
<paragraph blockId="15.[199,2358,2967,3150]" pageId="15" pageNumber="512">
|
||
FIGURE 6. Restored skull with occluded jaws of a Stage 1
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[1130,1409,2967,2999]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="15" pageNumber="512" phylum="Chordata" rank="species" species="rex">Tyrannosaurus rex</taxonomicName>
|
||
(CMNH 7541) in left lateral (A), dorsal (B), occipital (C), and palatal (D) views. Skull length is 572 mm. Rostral and transverse crushing of the suspensorium in A and B has not been corrected. Basisphenoid pneumatic foramina are restored in D; right squamosal is restored in B; occipital condyle is restored in C. Abbreviations: ang, os angulare; ar, os articulare; bo, os basioccipitale; bs, os basisphenoidale; bs rec cl, basisphenoid recess ceiling; co, os coronoideum; cr sag, crista sagittalis; dn, os dentale; ect, os ectopterygoideum; imf, fenestra intramandibulare; ipv, vacuita interpterygoideum; la, os lacrimale; mx, os maxillare; na,
|
||
</paragraph>
|
||
<paragraph blockId="16.[204,2364,2964,3109]" pageId="16" pageNumber="513">FIGURE 6. Continued os nasale; ot, os otoccipitale; pa, os parietale; pl, os palatinum; pmx, os premaxillare; pra, os prearticulare; prf, os prefrontale; pt, os pterygoideum; qj, os quadratojugale; qu, os quadratum; qu for, foramen quadratum; rec pnu bs, recessus pneumaticum basisphenoidale; rec pn pl, recessus pneumaticum palatinum; sq, os squamosum; spl, os spleniale; spl fen, fenestra spleniale; suborb fen, fenestra suborbitalis; sur, os surangulare; tp, tooth puncture; vo, vomer.</paragraph>
|
||
</caption>
|
||
<caption ID-DOI="http://doi.org/10.5281/zenodo.3958115" ID-Zenodo-Dep="3958115" httpUri="https://zenodo.org/record/3958115/files/figure.png" pageId="17" pageNumber="514" startId="17.[197,327,1679,1711]" targetBox="[210,2334,264,1638]" targetPageId="17">
|
||
<paragraph blockId="17.[197,2352,1679,1748]" pageId="17" pageNumber="514">
|
||
FIGURE 7. Immature bone grain on the lateral surface of the antorbital fossa of the maxilla (A; reversed), jugal (B), surangular (C), and the dorsal surface of the nasal and frontal (D) of an early ontogeny
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[1163,1440,1716,1748]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="17" pageNumber="514" phylum="Chordata" rank="species" species="rex">Tyrannosaurus rex</taxonomicName>
|
||
(CMNH 7541). Skull length is 572 mm.
|
||
</paragraph>
|
||
</caption>
|
||
<subSubSection box="[197,752,1924,1959]" pageId="17" pageNumber="514" type="nomenclature">
|
||
<paragraph blockId="17.[195,1252,1923,3106]" box="[197,752,1924,1959]" pageId="17" pageNumber="514">
|
||
Ontogeny in
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[430,752,1924,1959]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="17" pageNumber="518" phylum="Chordata" rank="species" species="rex">Tyrannosaurus rex</taxonomicName>
|
||
</paragraph>
|
||
</subSubSection>
|
||
<subSubSection lastPageId="19" lastPageNumber="516" pageId="17" pageNumber="514" type="description">
|
||
<paragraph blockId="17.[195,1252,1923,3106]" pageId="17" pageNumber="514">
|
||
Ontogeny in the craniofacial skeleton of
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[937,1251,1988,2024]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="17" pageNumber="514" phylum="Chordata" rank="species" species="rex">Tyrannosaurus rex</taxonomicName>
|
||
is characterized by a global shift from a gracile early ontogeny to a robust late ontogeny morphotype. In
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[885,980,2071,2107]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="17" pageNumber="514" phylum="Chordata" rank="species" species="rex">T. rex</taxonomicName>
|
||
the rostral maxillary and dentary teeth become conical, expanding and deepening the alveolar processes of the maxilla and dentary (
|
||
<figureCitation captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="17" pageNumber="514" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8A, C, E, F</figureCitation>
|
||
). The tooth row becomes rostrodorsally reoriented, and the teeth become procumbent (
|
||
<bibRefCitation author="Bakker, R. T. & M. Williams & P. J. Currie" box="[796,1129,2238,2274]" journalOrPublisher="Hunteria" pageId="17" pageNumber="514" pagination="1 - 30" part="1" refId="ref18472" refString="Bakker, R. T., M. Williams, and P. J. Currie. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana. Hunteria 1: 1 - 30." title="Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana" type="journal article" year="1988">Bakker et al., 1988</bibRefCitation>
|
||
). Also, the maxilla loses three to four teeth from the rostral end of the tooth row, because the rostral teeth undergo the greatest change. Although tooth count has been used to distinguish tyrannosaurid taxa (e.g.,
|
||
<bibRefCitation author="Bakker, R. T. & M. Williams & P. J. Currie" box="[500,836,2404,2440]" journalOrPublisher="Hunteria" pageId="17" pageNumber="514" pagination="1 - 30" part="1" refId="ref18472" refString="Bakker, R. T., M. Williams, and P. J. Currie. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana. Hunteria 1: 1 - 30." title="Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana" type="journal article" year="1988">Bakker et al., 1988</bibRefCitation>
|
||
), caution is advised because counts appear to be sensitive to ontogenetic and individual variation.
|
||
</paragraph>
|
||
<paragraph blockId="17.[195,1252,1923,3106]" pageId="17" pageNumber="514">
|
||
A similar pattern of loss of tooth positions is present in the maxilla of
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[385,566,2571,2607]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="17" pageNumber="514" phylum="Chordata" rank="species" species="libratus">A. libratus</taxonomicName>
|
||
, dropping from 16 to 13 alveoli (
|
||
<tableCitation captionStart="TABLE 2" captionStartId="19.[195,311,276,308]" captionTargetBox="[338,2239,393,800]" captionTargetPageId="19" captionText="TABLE 2. Maxillary tooth counts of maxillary alveoli, growth stage, and skull lengths of Albertosaurus libratus specimens showing a tendency for more mature specimens to have fewer tooth positions. () = estimated." httpUri="http://table.plazi.org/id/D3D46639FFBBFFC976A1FEEAFAF6FEE2" pageId="17" pageNumber="514" tableUuid="D3D46639FFBBFFC976A1FEEAFAF6FEE2">Table 2</tableCitation>
|
||
). Although one large Stage 1 specimen (USNM 12814) has a low alveolus count, this specimen is the most mature of the growth stage (Carr, in prep.). While loss of alveoli may be individually variable, it is evident that the phenomenon occurs in mature specimens (
|
||
<tableCitation box="[578,711,2779,2815]" captionStart="TABLE 2" captionStartId="19.[195,311,276,308]" captionTargetBox="[338,2239,393,800]" captionTargetPageId="19" captionText="TABLE 2. Maxillary tooth counts of maxillary alveoli, growth stage, and skull lengths of Albertosaurus libratus specimens showing a tendency for more mature specimens to have fewer tooth positions. () = estimated." httpUri="http://table.plazi.org/id/D3D46639FFBBFFC976A1FEEAFAF6FEE2" pageId="17" pageNumber="514" tableUuid="D3D46639FFBBFFC976A1FEEAFAF6FEE2">Table 2</tableCitation>
|
||
). Among other archosaurs, ontogenetic tooth loss has been reported by
|
||
<bibRefCitation author="Mook, C. C." box="[921,1147,2820,2856]" journalOrPublisher="Bulletin of the American Museum of Natural History" pageId="17" pageNumber="514" pagination="51 - 66" part="64" refId="ref19357" refString="Mook, C. C. 1921. Individual and age variation in the skulls of recent Crocodilia. Bulletin of the American Museum of Natural History 64: 51 - 66." title="Individual and age variation in the skulls of recent Crocodilia" type="journal article" year="1921">Mook (1921)</bibRefCitation>
|
||
, Wermuth (1953), and
|
||
<bibRefCitation author="Iordansky, N. N." box="[492,774,2863,2899]" editor="C. Gans & T. S. Parsons" journalOrPublisher="Academic Press, New York" pageId="17" pageNumber="514" pagination="201 - 262" refId="ref18922" refString="Iordansky, N. N. 1973. The skull of the Crocodilia; pp. 201 - 262 in C. Gans and T. S. Parsons (eds.), Biology of Reptilia, Vol. 4. Academic Press, New York." title="The skull of the Crocodilia" type="book chapter" volumeTitle="Biology of Reptilia, Vol. 4" year="1973">Iordansky (1973)</bibRefCitation>
|
||
in Crocodylus cataphractus, C. porosus, C. siamensis, and Tomistoma schlegelii. This indicates that ontogenetic tooth loss among
|
||
<taxonomicName authorityName="Osborn" authorityYear="1906" box="[932,1205,2945,2981]" class="Reptilia" family="Tyrannosauridae" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="17" pageNumber="514" phylum="Chordata" rank="family">Tyrannosauridae</taxonomicName>
|
||
is not withXout precedent among Archosauria.
|
||
</paragraph>
|
||
<footnote pageId="17" pageNumber="514">
|
||
<paragraph blockId="17.[195,1252,1923,3106]" lastBlockId="17.[1301,2356,1924,3107]" pageId="17" pageNumber="514">
|
||
In agreement with Molnar’s detailed functional analysis (1973), the adult skull of
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[633,732,3070,3106]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="17" pageNumber="514" phylum="Chordata" rank="species" species="rex">T. rex</taxonomicName>
|
||
is constructed for forceful biting. In
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[1433,1533,1924,1960]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="17" pageNumber="514" phylum="Chordata" rank="species" species="rex">T. rex</taxonomicName>
|
||
, the dorsotemporal fossa becomes deeply excavated during ontogeny, reflecting hypertrophied adductor musculature (
|
||
<figureCitation box="[1463,1653,2009,2045]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="17" pageNumber="514" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8C, D</figureCitation>
|
||
). The entire skull is modified to accommodate the change, including the rostrally-oriented orbits (
|
||
<figureCitation captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="17" pageNumber="514" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8C, D, I, J</figureCitation>
|
||
). In concert with the increase in bite force, the muzzle and jaws become deep and contacts between bones are strengthened by peg-and-socket sutures, such as the nasomaxillary contact (
|
||
<figureCitation box="[1548,1675,2222,2258]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="17" pageNumber="514" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8E</figureCitation>
|
||
). The facial skeleton is buttressed to deliver and absorb the resultant forces of increased bite force, evidenced by the strut-like rostral margin of the antorbital fossa, which passes to the columnar dorsum of the snout. Also, the premaxillary dental arcade of early growth stages is abandoned for a sparser arrangement of teeth (
|
||
<figureCitation box="[1921,2084,2434,2470]" captionStart="FIGURE 8" captionStartId="19.[191,323,2848,2880]" captionTargetBox="[229,2348,284,3012]" captionTargetPageId="18" captionText="FIGURE 8. Comparison of Stage 1 (CMNH 7541) and Stage 4 (AMNH 5027, MOR 555) skulls of Tyrannosaurus rex in palatal (A, B), dorsal (C, D), lateral (E, F), caudal (G, H), and rostral (I, J) views. Numbered labels indicate T. rex autapomorphies: (1) nasal processes of the premaxillae tightly appressed throughout their entire length; (2) restricted exposure of the jugal within the antorbital fenestra; (3) antorbital fossa reaches the nasal suture caudodorsally; (4) transversely broad jugal pneumatic recess; (5) elongate frontal sagittal crest; (6) strongly divergent and short basal tubers; (7) rostroventrally-oriented caudal occipital plate; (8) shallow subcondylar recess; (9) rostroventrally deep basisphenoid plate and rostrocaudally-restricted basisphenoid recess; (10) inflated ectopterygoid; (11) strongly convex rostral plate of the surangular; (12) transversely narrow snout and broad temporal region relative to other tyrannosaurids; and (13) deep mandible relative to other tyrannosaurids." figureDoi="http://doi.org/10.5281/zenodo.3958117" httpUri="https://zenodo.org/record/3958117/files/figure.png" pageId="17" pageNumber="514" targetBox="[229,2348,284,3012]" targetPageId="18">Fig. 8I, J</figureCitation>
|
||
), indicating the less specialized grasping function characteristic of the remainder of the rostral maxillary tooth row.
|
||
</paragraph>
|
||
</footnote>
|
||
<paragraph blockId="17.[1301,2356,1924,3107]" pageId="17" pageNumber="514">
|
||
In addition, the craniofacial air sac system (sensu
|
||
<bibRefCitation author="Witmer, L. M." editor="P. J. Currie & E. M. Koster" journalOrPublisher="Occasional Paper of the Tyrrell Museum of Palaeontology" pageId="17" pageNumber="514" pagination="234 - 239" part="3" refId="ref19696" refString="Witmer, L. M. 1987. The nature of the antorbital fossa of archosaurs: shifting the null hypothesis; pp. 234 - 239 in P. J. Currie and E. M. Koster (eds.), Fourth Symposium on Mesozoic Terrestrial Ecosys- terns. Short Papers. Revised ed. Occasional Paper of the Tyrrell Museum of Palaeontology, 3" title="The nature of the antorbital fossa of archosaurs: shifting the null hypothesis" type="book chapter" volumeTitle="Fourth Symposium on Mesozoic Terrestrial Ecosys- terns. Short Papers. Revised ed" year="1987">Witmer, 1987</bibRefCitation>
|
||
,
|
||
<bibRefCitation author="Witmer, L. M." box="[1400,1475,2604,2640]" journalOrPublisher="Zoological Journal of the Linnean Society" pageId="17" pageNumber="514" pagination="327 - 378" part="100" refId="ref19765" refString="---- 1990. The craniofacial air sac system of Mesozoic birds (Aves). Zoological Journal of the Linnean Society 100: 327 - 378." title="The craniofacial air sac system of Mesozoic birds (Aves)" type="journal article" year="1990">1990</bibRefCitation>
|
||
,
|
||
<bibRefCitation author="Witmer, L. M." box="[1499,1573,2604,2640]" journalOrPublisher="Society of Vertebrate Paleontology Memoir" pageId="17" pageNumber="514" pagination="1 - 73" part="3" refId="ref19792" refString="---- 1997. The evolution of the antorbital cavity of archosaurs: a study in soft-tissue reconstruction in the fossil record with an anal- ysis of the function of pneumaticity. Society of Vertebrate Paleontology Memoir 3: 1 - 73; supplement to Journal of Vertebrate Paleontology 17 (1)." title="The evolution of the antorbital cavity of archosaurs: a study in soft-tissue reconstruction in the fossil record with an anal- ysis of the function of pneumaticity" type="journal article" year="1997">1997</bibRefCitation>
|
||
) had a primary role in modifying bone structure. The antorbital air sac rested within the antorbital fenestra and antorbital fossa, sending diverticula into the ectopterygoid, palatine, lacrimal, jugal, and maxilla. As maturity was attained, the diverticula invaded the bones more fully, expanding the sinuses and bones. Combined with changes induced by an enlarged dentition, late ontogeny specimens became ‘swollenfaced’ relative to their smaller, sleeker progeny. It is probable that the swollen bones had greater cross-sectional strength than the strap-like bones of smaller animals, a morphological shift that would be important for taking live prey.
|
||
</paragraph>
|
||
<paragraph blockId="17.[1301,2356,1924,3107]" lastBlockId="19.[195,1257,918,1703]" lastPageId="19" lastPageNumber="516" pageId="17" pageNumber="514">
|
||
Finally, pneumatic features indicate further ontogenetic change in
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[385,489,918,954]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="19" pageNumber="516" phylum="Chordata" rank="species" species="rex">T. rex</taxonomicName>
|
||
. The Stage 4 specimens
|
||
<materialsCitation ID-GBIF-Occurrence="3396378334" box="[942,1109,918,954]" collectionCode="AMNH" httpUri="http://research.amnh.org/paleontology/search.php?action=detail&specimen_id=52853 " pageId="19" pageNumber="516" specimenCode="CM 9380" specimenCount="1">
|
||
<specimenCode box="[942,1109,918,954]" pageId="19" pageNumber="516">CM 9380</specimenCode>
|
||
</materialsCitation>
|
||
,
|
||
<materialsCitation ID-GBIF-Occurrence="3396378344" collectionCode="LACM" httpUri="https://collections.nhm.org/dinosaur-institute/Display.php?irn=1028446&QueryPage=%2Fdinosaur-institute%2F&BackRef=ResultsList.php " pageId="19" pageNumber="516" specimenCode="LACM 23844" specimenCount="1">
|
||
<specimenCode pageId="19" pageNumber="516">LACM 23844</specimenCode>
|
||
</materialsCitation>
|
||
, and
|
||
<materialsCitation ID-GBIF-Occurrence="3396378335" box="[408,649,959,995]" collectionCode="UCMP" httpUri="https://ucmpdb.berkeley.edu/cgi/ucmp_query2?admin=&query_src=ucmp_index&table=ucmp2&spec_id=V118742&one=T " pageId="19" pageNumber="516" specimenCode="UCMP 118742" specimenCount="1">
|
||
<specimenCode box="[408,649,959,995]" pageId="19" pageNumber="516">UCMP 118742</specimenCode>
|
||
</materialsCitation>
|
||
share maxillary fenestrae that are rostrodorsally deep and extend medial to the rostral margin of the antorbital fossa to a greater degree than in other specimens (e.g.,
|
||
<materialsCitation ID-GBIF-Occurrence="3396378371" box="[295,520,1085,1121]" collectionCode="AMNH" httpUri="http://research.amnh.org/paleontology/search.php?action=detail&specimen_id=47761 " pageId="19" pageNumber="516" specimenCode="AMNH 5027" specimenCount="1">
|
||
<specimenCode box="[295,520,1085,1121]" pageId="19" pageNumber="516">AMNH 5027</specimenCode>
|
||
</materialsCitation>
|
||
,
|
||
<materialsCitation ID-GBIF-Occurrence="3396378325" box="[544,714,1085,1121]" collectionCode="BHI" pageId="19" pageNumber="516" specimenCode="BHI 2033" specimenCount="1">
|
||
<specimenCode box="[544,714,1085,1121]" pageId="19" pageNumber="516">BHI 2033</specimenCode>
|
||
</materialsCitation>
|
||
,
|
||
<materialsCitation ID-GBIF-Occurrence="3396378310" box="[736,923,1085,1121]" collectionCode="TMP" pageId="19" pageNumber="516" specimenCode="TMP 81.6.1" specimenCount="1">
|
||
<specimenCode box="[736,923,1085,1121]" pageId="19" pageNumber="516">TMP 81.6.1</specimenCode>
|
||
</materialsCitation>
|
||
,
|
||
<materialsCitation ID-GBIF-Occurrence="3396378384" box="[945,1120,1085,1121]" collectionCode="MOR" pageId="19" pageNumber="516" specimenCode="MOR 555" specimenCount="1">
|
||
<specimenCode box="[945,1120,1085,1121]" pageId="19" pageNumber="516">MOR 555</specimenCode>
|
||
</materialsCitation>
|
||
). In addition, the interfenestral strut is thin, and additional pneumatic foramina are present at the apex (
|
||
<materialsCitation ID-GBIF-Occurrence="3396378328" box="[789,986,1168,1204]" collectionCode="AMNH" httpUri="http://research.amnh.org/paleontology/search.php?action=detail&specimen_id=52853 " pageId="19" pageNumber="516" specimenCode="CMN 9380" specimenCount="1">
|
||
<specimenCode box="[789,986,1168,1204]" pageId="19" pageNumber="516">CMN 9380</specimenCode>
|
||
</materialsCitation>
|
||
) or at the base (
|
||
<materialsCitation ID-GBIF-Occurrence="3396378348" box="[208,448,1209,1245]" collectionCode="LACM" httpUri="https://collections.nhm.org/dinosaur-institute/Display.php?irn=1028446&QueryPage=%2Fdinosaur-institute%2F&BackRef=ResultsList.php " pageId="19" pageNumber="516" specimenCode="LACM 23844" specimenCount="1">
|
||
<specimenCode box="[208,448,1209,1245]" pageId="19" pageNumber="516">LACM 23844</specimenCode>
|
||
</materialsCitation>
|
||
) of the interfenestral strut.
|
||
</paragraph>
|
||
<caption ID-Table-UUID="D3D46639FFBBFFC976A1FEEAFAF6FEE2" httpUri="http://table.plazi.org/id/D3D46639FFBBFFC976A1FEEAFAF6FEE2" pageId="19" pageNumber="516" startId="19.[195,311,276,308]" targetBox="[338,2239,393,800]" targetIsTable="true" targetPageId="19">
|
||
<paragraph blockId="19.[194,2354,276,344]" pageId="19" pageNumber="516">
|
||
TABLE 2. Maxillary tooth counts of maxillary alveoli, growth stage, and skull lengths of
|
||
<taxonomicName baseAuthorityName="Lambe" baseAuthorityYear="1914" box="[1559,1891,276,308]" class="Reptilia" family="Tyrannosauridae" genus="Albertosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="19" pageNumber="516" phylum="Chordata" rank="species" species="libratus">Albertosaurus libratus</taxonomicName>
|
||
specimens showing a tendency for more mature specimens to have fewer tooth positions. () = estimated.
|
||
</paragraph>
|
||
</caption>
|
||
<paragraph blockId="19.[194,2356,379,823]" pageId="19" pageNumber="516">
|
||
<table box="[338,2239,393,800]" gridcols="4" gridrows="11" pageId="19" pageNumber="516">
|
||
<tr box="[338,2239,393,425]" gridrow="0" pageId="19" pageNumber="516">
|
||
<th box="[338,570,393,425]" gridcol="0" gridrow="0" pageId="19" pageNumber="516">Specimen</th>
|
||
<th box="[845,924,393,425]" gridcol="1" gridrow="0" pageId="19" pageNumber="516">Stage</th>
|
||
<th box="[1182,1545,393,425]" gridcol="2" gridrow="0" pageId="19" pageNumber="516"># Maxillary alveoli</th>
|
||
<th box="[1830,2239,393,425]" gridcol="3" gridrow="0" pageId="19" pageNumber="516">Skull length (mm)</th>
|
||
</tr>
|
||
<tr box="[338,2239,448,481]" gridrow="1" pageId="19" pageNumber="516">
|
||
<th box="[338,570,448,481]" gridcol="0" gridrow="1" pageId="19" pageNumber="516">AMNH 5664</th>
|
||
<td box="[845,924,448,481]" gridcol="1" gridrow="1" pageId="19" pageNumber="516">1</td>
|
||
<td box="[1182,1545,448,481]" gridcol="2" gridrow="1" pageId="19" pageNumber="516">
|
||
15 (
|
||
<bibRefCitation author="Bakker, R. T. & M. Williams & P. J. Currie" box="[1238,1525,449,481]" journalOrPublisher="Hunteria" pageId="19" pageNumber="516" pagination="1 - 30" part="1" refId="ref18472" refString="Bakker, R. T., M. Williams, and P. J. Currie. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana. Hunteria 1: 1 - 30." title="Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana" type="journal article" year="1988">Bakker et al., 1988</bibRefCitation>
|
||
)
|
||
</td>
|
||
<td box="[1830,2239,448,481]" gridcol="3" gridrow="1" pageId="19" pageNumber="516">
|
||
678 (
|
||
<bibRefCitation author="Russell, D. A." box="[1909,2112,449,481]" journalOrPublisher="National Museum of Natural Sciences Publications in Palaeontology" pageId="19" pageNumber="516" pagination="1 - 30" part="1" refId="ref19547" refString="Russell, D. A. 1970. Tyrannosaurs From the Late Cretaceous of Western Canada. National Museum of Natural Sciences Publications in Palaeontology 1: 1 - 30." title="Tyrannosaurs From the Late Cretaceous of Western Canada" type="journal article" year="1970">Russell, 1970</bibRefCitation>
|
||
)
|
||
</td>
|
||
</tr>
|
||
<tr box="[338,2239,484,517]" gridrow="2" pageId="19" pageNumber="516">
|
||
<th box="[338,570,484,517]" gridcol="0" gridrow="2" pageId="19" pageNumber="516">ROM 1247</th>
|
||
<td box="[845,924,484,517]" gridcol="1" gridrow="2" pageId="19" pageNumber="516">1</td>
|
||
<td box="[1182,1545,484,517]" gridcol="2" gridrow="2" pageId="19" pageNumber="516">14 (pers. obs.)</td>
|
||
<td box="[1830,2239,484,517]" gridcol="3" gridrow="2" pageId="19" pageNumber="516">(750) (pers. obs.)</td>
|
||
</tr>
|
||
<tr box="[338,2239,519,552]" gridrow="3" pageId="19" pageNumber="516">
|
||
<th box="[338,570,519,552]" gridcol="0" gridrow="3" pageId="19" pageNumber="516">USNM 12814</th>
|
||
<td box="[845,924,519,552]" gridcol="1" gridrow="3" pageId="19" pageNumber="516">1</td>
|
||
<td box="[1182,1545,519,552]" gridcol="2" gridrow="3" pageId="19" pageNumber="516">
|
||
13 (
|
||
<bibRefCitation author="Bakker, R. T. & M. Williams & P. J. Currie" box="[1238,1525,520,552]" journalOrPublisher="Hunteria" pageId="19" pageNumber="516" pagination="1 - 30" part="1" refId="ref18472" refString="Bakker, R. T., M. Williams, and P. J. Currie. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana. Hunteria 1: 1 - 30." title="Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana" type="journal article" year="1988">Bakker et al., 1988</bibRefCitation>
|
||
)
|
||
</td>
|
||
<td box="[1830,2239,519,552]" gridcol="3" gridrow="3" pageId="19" pageNumber="516">
|
||
(795) (
|
||
<bibRefCitation author="Russell, D. A." box="[1932,2135,520,552]" journalOrPublisher="National Museum of Natural Sciences Publications in Palaeontology" pageId="19" pageNumber="516" pagination="1 - 30" part="1" refId="ref19547" refString="Russell, D. A. 1970. Tyrannosaurs From the Late Cretaceous of Western Canada. National Museum of Natural Sciences Publications in Palaeontology 1: 1 - 30." title="Tyrannosaurs From the Late Cretaceous of Western Canada" type="journal article" year="1970">Russell, 1970</bibRefCitation>
|
||
)
|
||
</td>
|
||
</tr>
|
||
<tr box="[338,2239,553,587]" gridrow="4" pageId="19" pageNumber="516">
|
||
<th box="[338,570,553,587]" gridcol="0" gridrow="4" pageId="19" pageNumber="516">TMP 83.36.100</th>
|
||
<td box="[845,924,553,587]" gridcol="1" gridrow="4" pageId="19" pageNumber="516">1</td>
|
||
<td box="[1182,1545,553,587]" gridcol="2" gridrow="4" pageId="19" pageNumber="516">15 (pers. obs.)</td>
|
||
<td box="[1830,2239,553,587]" gridcol="3" gridrow="4" pageId="19" pageNumber="516">—</td>
|
||
</tr>
|
||
<tr box="[338,2239,588,623]" gridrow="5" pageId="19" pageNumber="516">
|
||
<th box="[338,570,588,623]" gridcol="0" gridrow="5" pageId="19" pageNumber="516">CMN 2270</th>
|
||
<td box="[845,924,588,623]" gridcol="1" gridrow="5" pageId="19" pageNumber="516">1</td>
|
||
<td box="[1182,1545,588,623]" gridcol="2" gridrow="5" pageId="19" pageNumber="516">15 (pers. obs.)</td>
|
||
<td box="[1830,2239,588,623]" gridcol="3" gridrow="5" pageId="19" pageNumber="516">—</td>
|
||
</tr>
|
||
<tr box="[338,2239,624,658]" gridrow="6" pageId="19" pageNumber="516">
|
||
<th box="[338,570,624,658]" gridcol="0" gridrow="6" pageId="19" pageNumber="516">CMN 12063</th>
|
||
<td box="[845,924,624,658]" gridcol="1" gridrow="6" pageId="19" pageNumber="516">1</td>
|
||
<td box="[1182,1545,624,658]" gridcol="2" gridrow="6" pageId="19" pageNumber="516">14 (pers. obs.)</td>
|
||
<td box="[1830,2239,624,658]" gridcol="3" gridrow="6" pageId="19" pageNumber="516">—</td>
|
||
</tr>
|
||
<tr box="[338,2239,661,693]" gridrow="7" pageId="19" pageNumber="516">
|
||
<th box="[338,570,661,693]" gridcol="0" gridrow="7" pageId="19" pageNumber="516">AMNH 5336</th>
|
||
<td box="[845,924,661,693]" gridcol="1" gridrow="7" pageId="19" pageNumber="516">2</td>
|
||
<td box="[1182,1545,661,693]" gridcol="2" gridrow="7" pageId="19" pageNumber="516">
|
||
13 (
|
||
<bibRefCitation author="Bakker, R. T. & M. Williams & P. J. Currie" box="[1238,1525,661,693]" journalOrPublisher="Hunteria" pageId="19" pageNumber="516" pagination="1 - 30" part="1" refId="ref18472" refString="Bakker, R. T., M. Williams, and P. J. Currie. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana. Hunteria 1: 1 - 30." title="Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana" type="journal article" year="1988">Bakker et al., 1988</bibRefCitation>
|
||
)
|
||
</td>
|
||
<td box="[1830,2239,661,693]" gridcol="3" gridrow="7" pageId="19" pageNumber="516">
|
||
(962) (
|
||
<bibRefCitation author="Bakker, R. T. & M. Williams & P. J. Currie" box="[1932,2218,661,693]" journalOrPublisher="Hunteria" pageId="19" pageNumber="516" pagination="1 - 30" part="1" refId="ref18472" refString="Bakker, R. T., M. Williams, and P. J. Currie. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana. Hunteria 1: 1 - 30." title="Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana" type="journal article" year="1988">Bakker et al., 1988</bibRefCitation>
|
||
)
|
||
</td>
|
||
</tr>
|
||
<tr box="[338,2239,697,730]" gridrow="8" pageId="19" pageNumber="516">
|
||
<th box="[338,570,697,730]" gridcol="0" gridrow="8" pageId="19" pageNumber="516">UA 10</th>
|
||
<td box="[845,924,697,730]" gridcol="1" gridrow="8" pageId="19" pageNumber="516">3</td>
|
||
<td box="[1182,1545,697,730]" gridcol="2" gridrow="8" pageId="19" pageNumber="516">13 (Currie, pers. comm.)</td>
|
||
<td box="[1830,2239,697,730]" gridcol="3" gridrow="8" pageId="19" pageNumber="516">(900) (Currie, pers. comm.)</td>
|
||
</tr>
|
||
<tr box="[338,2239,733,765]" gridrow="9" pageId="19" pageNumber="516">
|
||
<th box="[338,570,733,765]" gridcol="0" gridrow="9" pageId="19" pageNumber="516">AMNH 5458</th>
|
||
<td box="[845,924,733,765]" gridcol="1" gridrow="9" pageId="19" pageNumber="516">3</td>
|
||
<td box="[1182,1545,733,765]" gridcol="2" gridrow="9" pageId="19" pageNumber="516">14 (pers. obs.)</td>
|
||
<td box="[1830,2239,733,765]" gridcol="3" gridrow="9" pageId="19" pageNumber="516">
|
||
990 (
|
||
<bibRefCitation author="Russell, D. A." box="[1910,2113,733,765]" journalOrPublisher="National Museum of Natural Sciences Publications in Palaeontology" pageId="19" pageNumber="516" pagination="1 - 30" part="1" refId="ref19547" refString="Russell, D. A. 1970. Tyrannosaurs From the Late Cretaceous of Western Canada. National Museum of Natural Sciences Publications in Palaeontology 1: 1 - 30." title="Tyrannosaurs From the Late Cretaceous of Western Canada" type="journal article" year="1970">Russell, 1970</bibRefCitation>
|
||
)
|
||
</td>
|
||
</tr>
|
||
<tr box="[338,2239,768,800]" gridrow="10" pageId="19" pageNumber="516">
|
||
<th box="[338,570,768,800]" gridcol="0" gridrow="10" pageId="19" pageNumber="516">CMN 2120</th>
|
||
<td box="[845,924,768,800]" gridcol="1" gridrow="10" pageId="19" pageNumber="516">3</td>
|
||
<td box="[1182,1545,768,800]" gridcol="2" gridrow="10" pageId="19" pageNumber="516">13 (pers. obs.)</td>
|
||
<td box="[1830,2239,768,800]" gridcol="3" gridrow="10" pageId="19" pageNumber="516">1,000 (pers. obs.)</td>
|
||
</tr>
|
||
</table>
|
||
</paragraph>
|
||
<paragraph blockId="19.[195,1257,918,1703]" pageId="19" pageNumber="516">
|
||
It is evident that the distinct structural patterns of early and late ontogeny specimens of
|
||
<taxonomicName authorityName="Osborn" authorityYear="1905" box="[679,777,1293,1329]" class="Reptilia" family="Tyrannosauridae" genus="Tyrannosaurus" higherTaxonomySource="GBIF,CoL" kingdom="Animalia" order="Dinosauria" pageId="19" pageNumber="516" phylum="Chordata" rank="species" species="rex">T. rex</taxonomicName>
|
||
constrained their respective foraging behaviors, which in late ontogeny individuals appears specialized to grasp and hold live prey or to dismember a large carcass. Alternatively, the changes represent a reaction norm to the size of the skull, increased bite forces, and increased prey size. Nonetheless, it is not improbable that small and large animals differed in foraging strategy, consumption technique, and/ or prey type. Such size dependent differences are found in extant crocodilians (
|
||
<bibRefCitation author="Grenard, S." bookContentInfo="210 pp." box="[501,745,1625,1661]" journalOrPublisher="Krieger Publishing Company, Malabar, Florida" pageId="19" pageNumber="516" refId="ref18843" refString="Grenard, S. 1991. Handbook of Alligators and Crocodiles. Krieger Publishing Company, Malabar, Florida, 210 pp." title="Handbook of Alligators and Crocodiles" type="book" year="1991">Grenard, 1991</bibRefCitation>
|
||
) and monitor lizards (
|
||
<bibRefCitation author="Auffenberg, W." bookContentInfo="419 pp" journalOrPublisher="University of Florida Press, Gainsville" pageId="19" pageNumber="516" refId="ref18435" refString="Auffenberg, W. 1988. Gray's Monitor Lizard. University of Florida Press, Gainsville, 419 pp" title="Gray's Monitor Lizard" type="book" year="1988">Auffenberg, 1988</bibRefCitation>
|
||
,
|
||
<bibRefCitation author="Auffenberg, W." bookContentInfo="560 pp." box="[406,489,1667,1703]" journalOrPublisher="University Press of Florida, Gainsville" pageId="19" pageNumber="516" refId="ref18456" refString="1994. The Bengal Monitor. University Press of Florida, Gainsville, 560 pp." title="The Bengal Monitor" type="book" year="1994">1994</bibRefCitation>
|
||
).
|
||
</paragraph>
|
||
</subSubSection>
|
||
</treatment>
|
||
</document> |