A New Clevosaurid from the Triassic (Carnian) of Brazil and the Rise of Sphenodontians in Gondwana

Autor(es):Mostrar menos -

Hsiou, Annie S. ^[1] ; Nydarn, Randall L. ^{[2, 3]} ; Simoes, Tiago R. ^{[4, 5]} ; Pretto, Flavio A. ^[6] ; Onary, Silvio ^[1] ; Martinelli, Agustin G. ^{[7, 8]} ; Liparini, Alexandre ^[9] ; Romo de Vivar Martinez, Paulo R. ^[7] ; Soares, Marina B. ^[7] ; Schultz, Cesar L. ^[7] ; Caldwell, Michael W. ^{[10, 5]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Lab Paleontol, Ribeirao Preto, SP - Brazil

^[2] Midwestern Univ, Coll Grad Studies, Arizona Coll Osteopath Med, Glendale, AZ 85308 - USA

^[3] Midwestern Univ, Coll Grad Studies, Dept Anat, Glendale, AZ 85308 - USA

^[4] Harvard Univ, Dept Organism & Evolutionary Biol, Museum Comparat Zool, Cambridge, MA 02138 - USA

^[5] Univ Alberta, Dept Biol Sci, Edmonton, AB - Canada

^[6] Univ Fed Santa Maria, CAPPA Ctr Apoio Pesquisa Paleontol Quarta Coloni, Sao Joao Do Polesine - Brazil

^[7] Univ Fed Rio Grande do Sul, Lab Paleontol Vertebrados, Porto Alegre, RS - Brazil

^[8] Consejo Nacl Invest Cient & Tecn, Secc Paleontol Vertebrados, Museo Argentino Ciencias Nat Bernardino Rivadavia, Buenos Aires, DF - Argentina

^[9] Univ Fed Sergipe, Dept Biol, PIBi Lab Lab Pesquisas Integrat Biodiversidade, Sao Cristovao, Sergipe - Brazil

^[10] Univ Alberta, Dept Earth & Atmospher Sci, Edmonton, AB - Canada

• Tipo de documento: Artigo Científico
• Fonte: SCIENTIFIC REPORTS; v. 9, AUG 14 2019.
• Citações Web of Science: 0

Resumo

The early evolution of lepidosaurs is marked by an extremely scarce fossil record during the Triassic. Importantly, most Triassic lepidosaur specimens are represented by disarticulated individuals from high energy accretion deposits in Laurasia, thus greatly hampering our understanding of the initial stages of lepidosaur evolution. Here, we describe the fragmentary remains of an associated skull and mandible of Clevosaurus hadroprodon sp. nov., a new taxon of sphenodontian lepidosaur from the Late Triassic (Carnian; 237-228 Mya) of Brazil. Referral to Sphenodontia is supported by the combined presence of a marginal dentition ankylosed to the apex of the dentary, maxilla, and premaxilla; the presence of `secondary bone' at the bases of the marginal dentition; and a ventrally directed mental process at the symphysis of the dentary. Our phylogenetic analyses recover Clevosaurus hadroprodon as a clevosaurid, either in a polytomy with the Late Triassic to Early Jurassic Clevosaurus and Brachyrhinodon (under Bayesian inference), or nested among different species of Clevosaurus (under maximum parsimony). Clevosaurus hadroprodon represents the oldest known sphenodontian from Gondwana, and its clevosaurid relationships indicates that these sphenodontians achieved a widespread biogeographic distribution much earlier than previously thought. (AU)

• Processo FAPESP: 11/14080-0 - Os Squamata (Reptilia, Lepidosauria) do Cretáceo e Terciário (Paleogeno/Neogeno) das bacias Bauru, Aiuruoca e Acre: sistemática, evolução e paleoambientes
• Beneficiário: Annie Schmaltz Hsiou
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores