A new scincomorph lizard from the Early Cretaceous of Puebla, Mexico

Citation
Vh. Reynoso et G. Callison, A new scincomorph lizard from the Early Cretaceous of Puebla, Mexico, ZOOL J LINN, 130(2), 2000, pp. 183-212
Citations number
37
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences
Journal title
ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY
ISSN journal
0024-4082 → ACNP
Volume
130
Issue
2
Year of publication
2000
Pages
183 - 212
Database
ISI
SICI code
0024-4082(200010)130:2<183:ANSLFT>2.0.ZU;2-E
Abstract
A complete skeleton of a new scincomorph lizard from the Early Cretaceous d eposits of Tepexi de Rodriguez is described. Tepexisaurus tepexii gen. et s p, nov. is the best preserved early scincomorph and the first known taxon t hat is morphologically primitive to scincoids and paramacellodid lizards. T he presence of pointed ventral parietal downgrowths, the coronoid overlappe d anteriorly and posteriorly by the dentary and surangular, a small medial flange on the retroarticular process, and weak zygosphene and zygantrum art iculations suggest scincoid relationships, but the absence of ventral and d orsal osteoscutes place Tepexisaurus as sister-group of this taxon. It shar es die presence of +/- 30 closely packed teeth with the poorly known Upper Jurassic genus Saurillus and Pseudosaurillus, but differences in the corono id structure, Meckelian groove and jaw proportions indicate that both taxa are distinct. Similar to Tepexisaurus, the absence of osteoscutes in Sauril lus, Pseudosaurillus and Saurillodon place these taxa in a more primitive p osition relative to other paramacellodids which should be included within S cincoidea. Thus, Paramacellodidae as previously defined is a paraphyletic a ssemblage. The late presence of a pre-scincoid lizard in the Albian deposit s of Tlayua can be correlated with the presence of sphenodontians and the r elictual nature of the basal squamate Huehuecuetzpalli mixtecus. It gives a dditional evidence to support the hypothesis that Tlayua was a refuge for t errestrial archaic forms during the Albian. (C) 2000 The Linnean Society of London.