Lamnoid vertebrae from the Agua Nueva Formation (Upper Cretaceous: lower Turonian), northeastern Mexico

  • Alberto Blanco-Piñón Centro de Investigaciones en Ciencias de la Tierra, Universidad Autónoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo Km. 4.5. Pachuca, Hidalgo. Mexico.
  • Kenshu Shimada Environmental Science Program and Department of Biological Sciences, DePaul University, 2325 North Clifton Avenue, Chicago, Illinois 60614, USA. Sternberg Museum of Natural History, Fort Hays State University, Hays, Kansas 67601, USA.
  • Gerardo González-Barba Departmento de Geología, Universidad Autónoma de Baja California Sur, Apartado.Postal 19B, 23080 La Paz, Baja California Sur, Mexico.
Keywords: lamniform, shark, vertebral series, Turonian, Vallecillo, Mexico.

Abstract

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.

Published
2018-04-25
Issue
Vol 22 No 1 (2005)
Section
Regular Papers

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