Irregular echinoids (Order Spatangoida) from the Cretaceous of Mexico

Echinoids are a very important part of the Mesozoic and Cenozoic fossil fauna of Mexico. Among them, spatangoids are widely represented in several Cretaceous fossiliferous outcrops, and have stratigraphical and paleoecological value due to their good preservation of the Cretaceous. The review of order Spatangoida L. Agassiz, 1840 from the Cretaceous in Mexico allowed un update the taxonomy of species and contributed to the study of paleogeographic and stratigraphic distribution. The order Spatangoida is the most diverse in Mexico with three families (Toxasteridae, Hemiasteridae, Micrasteridae), seven genera (Epiaster, Heteraster, Macraster, Washitaster, Hemiaster, Proraster, Micraster) and 21 species. Family Toxasteridae is the most numerous with 54 % of the species reported for the Cretaceous of Mexico. Spatangoids from the Cretaceous of Mexico are found in different localities in Sonora (Cerro de las Conchas), Chihuahua (Cerro de Muleros, Sierra de Juarez, Placer de Guadalupe, Sierras La Ranchera, El Presidio, Sierra Banco de Lucero, Sierra La Encantada, Villa Ahumada), Coahuila (Sierra de Tlahualilo), Nuevo Leon (Sinclinal de Delgado), San Luis Potosi (Zamachihue), Colima (El Rosario), Puebla (San Juan Raya, Barranca Salitrillo), Guerrero (Cerro de Ahuexotitlan) and Oaxaca (Las Huertas).