Reptiles marinos mesozoicos en el sureste de México y su significación geológico-paleontológica

Abstract

The Papalutla reptiliofaunule, Neocomian of the Huajuapan de León Municipality, Oaxacan Mixteca Region, Mexico, is described; it proceeds from an unnamed formation consisting of marly silty limestone bearing fish, reptiles and ammonites; the age of the formation and of the fauna was determined on the basis of the latter fossils. The reptiliofaunule consists of Thalattosuchia Fam., Gen. et sp. indet. (Archosauria-Crocodylia), represented by three dorsal vertebrae that would be the first record of this infraorder in Middle America, as well as the oldest and southernmost record of the Order Crocodylia in Mexico, and of Gen. nov. aff. Pliosaurus sp. (Sauropterygia-Plesiosauria), represented by a toothed rostral fragment and a cervical vertebral centrum that seems to be the first certain Early Cretaceous record of the Family Pliosauridae in the American Continent, a fact in itself very significant. Dowload full text.