BOLETÍN DE LA SOCIEDAD GEOLÓGICA MEXICANA Vol 65, Núm. 3, 2013, P. 533-551 http://dx.doi.org/10.18268/BSGM2013v65n3a8

Bivalvos guadalupianos (Pérmico medio) de la Formación Olinalá, Guerrero, México

Miguel Guerrero-Sánchez¹, Sara A. Quiroz-Barroso^2,*

¹Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México D.F., México.
²Museo de Paleontología, Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México D.F., México.

* This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

The study material comes from rocks that outcrop northeast of the town Olinalá, in Guerrero state. The marine facies of Olinalá Formation are included in light to dark gray shale with fossils of brachiopods, gastropods, bivalves, cephalopods, crinoids stems, wood and other plant remains, locally included in concretions. The diversity of bivalves is represented by the infaunal species Nuculavus levatiformis, Palaeoneilo mcchesneyana, Edmondia phosphatica, and ?Cardiomorpha sp.; the epifaunal species, adhered to different substrates Posidoniella sp., Septimyalina burmai, and Leptodesma (Leptodesma) sp.; and the semi-infaunal species Bakevellia sp. The lifestyle and preservation characteristics of bivalves indicate that they were shortly transported before its final deposition, which occurred on a platform, in shallow water. The studied bivalve species are consistent with the permian age of this formation, considered previously by other authors based on the study of ammonites and foraminifera, and support the idea of their relationship with contemporary faunas of North America.

Palabras clave: Olinalá Formation, bivalves, middle Permian, Mexico.