Fossil fishes from the Mexcala Formation Upper Cretaceous in the Guerrero State, Mexico Los peces fosiles de la formacion Mexcala Cretacico Superior en el Estado de Guerrero, Mexico

Alvarado-Ortega, J.; Garibay-Romero, L. M.; Blanco-Pinon, A.; Gonzalez-Barba, G.; Vega, F. J.; Centeno-Garcia, E.

Just discovered fossil fishes from Guerrero State, Mexico, are described. The specimens were collected in six localities from the Upper Cretaceous (Turonian-Maastrichtian) Mexcala Formation and belong to different chondrichthyan groups. The fish remains include teeth of Ptychodus mortoni, P. decurrens, Serratolamna serrata, Squalicorax sp., and Cretoxyrhina cf. mantelli, as well as unidentified lamniforin vertebrae. Identified osteichthyans include remains of ichthyodectiforms, Tselfatia sp., Enchodus sp., Pachyrhizodus cf. caninus, dercetids, and several bones, teeth and scales of unidentified taxa. This contribution represents the southern most report of Upper Cretaceous fishes in North America, suggesting that these groups had a wider geographic distribution than previously thought; including the Western Tethys Sea or Paleo-gulf of Mexico. The youngest report (Maastrichtian) of Ptychodus mortoni is documented.