Resumo

ESTRADA-RUIZ, Emilio; MARTINEZ-CABRERA, Hugo I.; CALLEJAS-MORENO, Judith  e  UPCHURCH, JR., Garland R.. Cretaceous tropical rainforests from northern Mexico and its relationship with south-central North American floras. Polibotánica [online]. 2013, n.36, pp.41-61. ISSN 1405-2768.

Previous studies suggest that tropical and paratropical forests dominated by angiosperms had an important distribution throughout North America during the Early Cenozoic (Paleocene-Eocene). Recent research indicates that warm and wet forests were present in northern Mexico and south-central of U.S. during the Late Cretaceous (ca. 73 Ma). In Coahuila, the floras from the Cerro del Pueblo and Olmos formations represent vegetation types with tropical and paratropical affinities. In this paper we briefly review of the floristic composition and physiognomy of leaf and wood, and paleoecological interpretation of the floras from the Western interior of North America and northern Mexico. In addition, we analyzed floristic similarity patterns based on wood morphogenera. We show that floristic similarity patterns among paleofloras observe some geographic structure. There are, however, some morphogenera widely distributed across the region and other endemic to particular floras, which might suggest some degree of floristic differentiation. The validity of the patterns presented here is however preliminary and contingent to further identification of the fossil from these formations.

Palavras-chave : Tropical rainforests; Late Cretaceous; Northern Mexico; South-Central North America; fossil plants.