Dinosaur fossils discovered in Mexico have an age ranging from 199.6 million years in the Early Jurassic to 65.5 million years in the Late Cretaceous.
In San Martín Atexcal, town located in the region of Tehuacán, Puebla, are traces that correspond to the Early Cretaceous stage of 145.5 million years ago, located in Atexcal.
The fossil reserve stands out because most of the fossils in Mexico were recorded in the late Cretaceous, with an approximate 99.6 to 65.5 million years. Atexcal has dinosaur fossils, bones and icnological evidences, tracks, coprolites or excrement, nests and egg shells.