The cranial anatomy of Chinese placodonts and the phylogeny of Placodontia (Diapsida: Sauropterygia). (20th May 2015)

• Record Type: Journal Article
• Authors: Neenan, James M.; Li, Chun; Rieppel, Olivier; Scheyer, Torsten M.
• Is Part Of: Zoological journal of the Linnean Society. Volume 175:Number 2(2015:Oct.)
• Page Start: 415
• Page End: 428
• Publication Date: 2015-05-20
• Subjects: Zoology -- Periodicals; 590
• DOI: 10.1111/zoj.12277
• Languages: English
• ISSNs: 0024-4082

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Placodonts are Triassic marine reptiles that inhabited the eastern and western margins of the Tethys Ocean (modern South China and Europe/Middle East). Although the crania of European taxa are relatively well understood, those of Chinese taxa have not been extensively studied, and most of them have not been incorporated into a comprehensive phylogeny. Here we present the first reconstructions of all known Chinese placodont holotype skulls using micro‐computed tomographic (μCT) scanning and/or detailed anatomical study. We also present the first phylogenetic analyses that incorporate all placodont genera using a general diapsid matrix that includes postcranial characters, and a placodont‐only cranial matrix. Results vary between the matrices; however, both support a monophyletic Placodontia with eastern taxa interspaced throughout, indicating no major separation between the eastern and western Tethyan realms. Support is strong for a western Tethyan origin of Placodontia, although the highly nested Placochelyidae first appear in the upper Middle Triassic of the eastern Tethys. Thus, all placodont clades appear to have originated in a period of intense speciation during the Middle Triassic. © 2015 The Linnean Society of London</p> </abstract>