The cranial morphology of the temnospondyl Australerpeton cosgriffi (Tetrapoda: Stereospondyli) from the Middle-Late Permian of Parana Basin and the phylogenetic relationships of Rhinesuchidae

Autor(es)

Eltink, Estevan ; Dias, Eliseu V. ; Dias-da-Silva, Sergio ; Schultz, Cesar L. ; Langer, Max C.

• Tipo de documento: Artigo Científico
• Fonte: ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY; v. 176, n. 4, p. 26-pg., 2016-04-01.

Resumo

Stereospondyls are a diverse and morphologically distinctive clade of basal tetrapods that rapidly reached a global distribution and high abundance during the Early Triassic. Yet, the first stereospondyls appeared in the Middle-Late Permian of Gondwana, mostly represented by Rhinesuchidae. Australerpeton cosgriffi is a long-snouted representative of the group and one of the most complete temnospondyls known from the Permian of South America. The elements attributed to Au.cosgriffi were recovered from the Middle-Late Permian deposits of the Rio do Rasto Formation (Parana Basin), in the Serra do Cadeado area of Brazil. Here, we review the cranial anatomy of the species, providing a comparative redescription, new anatomical data and previously unrecognized characters. Australerpeton cosgriffi is nested within Rhinesuchidae based on the anatomy of the tympanic cavity, but its long-snouted condition is unique amongst rhinesuchids. Based on the recovered information and new morphological data, the systematic position of Au.cosgriffi was assessed using a new matrix of 221 characters; of which 196 were selected from previous studies and the remaining are newly proposed. The results show Rhinesuchidae divided into Rhinesuchinae and Australerpetinae. A unique tympanic cavity formed by a well posteroventrally projected tabular horn, stapedial groove, well-developed oblique crest on the pterygoid, and a dorsal pterygoid crest (new term) characterizes the ear region of Rhinesuchidae. Australerpeton cosgriffi is the only undisputed Rhinesuchidae record outside southern Africa and the first long-snouted Stereospondyli, and thus is useful in helping to understand the diversification of the stereospondyls during the Middle/Late Permian of Gondwana. (AU)

• Processo FAPESP: 09/54656-9 - Revisão da anatomia craniana e das relações filogenéticas de Australerpeton cosgriffi (Tetrapoda: Temnospondyli)
• Beneficiário: Estevan Eltink Nogueira
• Modalidade de apoio: Bolsas no Brasil - Doutorado