Diversity of late cretaceous dinosaurs from Mexico

Abstract

For many years the diversity of dinosaurs of Mexico during the Late Cretaceous has been poorly understood. This is due to the limited taxonomical determinations and the abundant undescribed material. This paper presents a new review of the up-to-date osteological record of Late Cretaceous dinosaurs from Mexico, based on published papers, unpublished data and direct observation of the material housed in Mexican paleontological collections and in the field. Some diagnostic dinosaur bones were taxonomically reassigned and others reported in the literature were located in collections. We document new localities with dinosaur remains in Fronteras Sonora, Manuel Benavides and Jiménez Chihuahua, General Cepeda and Saltillo Coahuila. Additionally we report new material relating to tyrannosaurids, ornithomimids, ankylosaurs, ceratopsids and hadrosaurids which extends their geographic and temporal distribution in Mexico. This investigation has revealed a dinosaur faunal assemblage consistent with others studies of North American Late Cretaceous faunas, abundant large bodied dinosaurs and poorly represented small dinosaurs. The lack of oviraptorosaurs, lepoceratopsids and thescelosaurids suggests the need to develop new method in the search for small dinosaurs in order to gain a more complete picture of dinosaur communities in Mexico and North America during the Late Cretaceous.