Fossil assemblages, mainly foraminifers and rudists, from the early Aptian of southwestern México. Palaeobiogeographical consequences for the Caribbean region.

Abstract

A caprinid rudist association with Amphitriscoelus waringi Harris and Hodson, Praecaprina sp. cf. ? P. pennyi Harris and Hodson, Caprina sp. cf. C. douvllei Paquier and ? Offneria sp. is reported from Turitzio, State of Michoacán, México. It occurs together with the foraminifera Palorbitolina lenticularis (Blumenbach), Choffatella decipiens Schlumberger and Everticyclammina sp. and the algae Delojfrella quercifoliipora Granier and Michaud, Marinella lugeoni Pfender and Arabicodium sp. The study of tha embryonic apparatusses of the specimens of Palorbitolina from this locality indicates an earliest Aptian age for that population. The presence of Amphitriscoelus and the other associated caprinids in México, constitutes evidence supporting the biotic homogeneity of the Caribbean Province during the Early Cretaceous.