Abstract

BLANCO-PINON, Alberto; SHIMADA, Kenshu  and  GONZALEZ-BARBA, Gerardo. Lamnoid vertebrae from the Agua Nueva Formation (Upper Cretaceous: lower Turonian), northeastern Mexico. Rev. mex. cienc. geol [online]. 2005, vol.22, n.1, pp.19-23. ISSN 2007-2902.

A partial vertebral series of a lamniform shark (Chondrichthyes: Elasmobranchii) occurred in the “Vallecillo fish Member” of the Agua Nueva Formation (Upper Cretaceous: Lower Turonian) at Vallecillo, Mexico. Its taxonomic assignment below the ordinal level is tenuous, but the vertebrae closely resemble those of cretoxyrhinid sharks.This report represents the first documentation of a Cretaceous lamniform shark in northeastern Mexico. The shark could have measured slightly over 3 m in total body length. Because the vertebrae are articulated and are three-dimensionally preserved, they are thought to be deposited rather quickly on a soft oceanfloor after decomposition of most of the shark carcass.

Keywords : lamniform; shark; vertebral series; Turonian; Vallecillo; Mexico.

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