THE MEXICAN HADROSAURS (ORNITHOPODA, HADROSAUROIDEA): A CRITIC REVISION

Abstract

This manuscript provides an updated overview of the knowledge about Mexico's hadrosaurs through the critical review of 173 publications between 1913 and 2019, which report osteological, icnological, tegumentary, dental and oolytic remains of these organisms. The data were synthesized and analyzed using traditional statistical methods, accumulation curves and sampling efforts. In addition, a catalogue of 166 paleontological sites carrying the remains of these organisms is provided, whose deposits belong to 18 geological units, whose ages are located between the Albian and the Maastrichtian age, present in the states of Baja California, Sonora, Chihuahua, Coahuila, Puebla and Michoacán. The data collected allow to recognize a comparatively low taxonomic diversity with respect to the rest of North America, even though the study of these dinosaurs began systematically since the 80's in Mexico. Only five species have been described from the very least from the bony remains and have been identified a single icnosepecie of the group. While other remains of hadrosaurs in the country have only been vaguely identified. The review of the history of the study of hadrosaurs in Mexico, as well as the  curves of the corresponding sampling effort, suggest that these dinosaurs were diverse and abundant in this country and also had an abundance and diversity different from the rest of America.