PRESENCE OF AN “ANILIOID” SNAKE FROM THE LATE CRETACEOUS OF ADAMANTINA FORMATION, BRAZIL

PRESENCE OF AN “ANILIOID” SNAKE FROM THE LATE CRETACEOUS OF ADAMANTINA...

Thiago Schineider FACHINI1 and Annie Schmaltz HSIOU

1 Departamento de Biologia, FFCLRP, Universidade de São Paulo; Av. Bandeirantes

3900, Ribeirão Preto-SP, Brazil. schumaker51@hotmail.com anniehsiou@ffclrp.usp.br

The “Anilioidea”, a group of basal alethinophidians considered by some authors to be a paraphyletic group, is comprised of taxa that retain certain lizard-like features and are as well specialized to fossorial habits. The Brazilian “anilioid” fossil record is relatively diverse but represented by undescribed vertebrae from the Late Cretaceous Adamantina Formation (Bauru Group), as well as three genera from the Late Paleocene of São José de Itaborí (Itaboraí Basin). Here we present new vertebral material of “Anilioidea”, obtained at a roadside of rural road that connects Monte Alto and Taiaçu municipalities, where outcrop rocks of the Late Cretaceous Adamantina Formation (Turonian- Santonian). The same area also provided crocodyliforms (Montealtosuchus arrudacamposi Carvalho, Vasconcellos, and Tavares 2007) and some remains of undetermined titanosaur sauropods. The material MPMA 16-0008-08 includes seven small to middle-sized precloacal vertebrae inserted on matrix. They are composed by three articulated posterior trunk vertebrae, two articulated vertebrae and two disarticulated mid-trunk vertebrae. The new “anilioid” snake is characterized by the following combination of characters: general depressed aspect, a clearly depressed neural arch, prominent and strongly inclined zygapophyses, short prezygapophyseal process, a shallow median notch in the posterior border of the neural arch, a centrum that is not markedly widened anteriorly and the absence of paracotylar foramina. Although this work is preliminary, the new material is not a madtsoiid snake or Najash rionegrina (Apesteguía and Zaher, 2006) by the absence of paracotylar foramina, also distinguish from them by the presence of strongly inclined zygapophyses and prezygapophyseal process. It contributes to greater knowledge about the group in the Cretaceous of South America, where relationships among the fossil taxa are still unclear.

Gomez, R.O.; Baez, A.M. and Rougier, G.W. 2008. An aniloid snake from the Upper Cretaceous of northern

Patagonia. Cretaceous Research 29: 481-488.

Carvalho, I.S; Vasconcellos, F.M. and Tavares, S.A.S. 2007. Montealtosuchus arrudacamposi, a new peirosaurid crocodile (MesoeucrocodylIa) from the late Cretaceous Adamantina Formation of Brazil. Zootaxa 1607: 35-46.

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