Abstract

BUITRON SANCHEZ, Blanca E.; LOPEZ LARA, Oscar; VACHARD, Daniel  and  HERNANDEZ BARROSO, Andrea Sarai. Algunos crinoides (Echinodermata-Crinoidea) del Pérmico de la región de Pemuxco, Hidalgo. Bol. Soc. Geol. Mex [online]. 2017, vol.69, n.1, pp.21-34. ISSN 1405-3322.

From outcrops of the Permian Tuzancoa Formation in the region of Pemuxco, Hidalgo State, México, five species of crinoids are described Cylindrocaulis cusfiski Moore & Jeffords, 1968, Baryschir anosus Moore & Jeffords, 1968, Cyclocaudex costatus Moore & Jeffords, 1968, Cyclocaudex jucundus Moore & Jeffords, 1968, Cycloscapus laevis Moore & Jeffords, 1968. The presence in these outcrops of the Skinnerella fusulinid, on the same level as the crinoids, determines the precise age of the lower Permian sequence (Leonardian) for this sequence.

The crinoids assemblage of Pemuxco region probably lived in a bathyal environment of flysch facies, which correspond ed to a rhythmic deposit present in the Tuzancoa Formation and suggesting a shallow water environment in an unstable geotectonic setting. The occurrence of continental plants remains could indicate that they were transported.

Crinoids have been cited in other parts of the upper Paleozoic of Mexico that includes Calnali, Hidalgo, Puebla Patlanoaya and Cuxtepeque, Ixtaltepec, Oaxaca, Peregrina Canyon, Tamaulipas, and The El Tule and Mesteñas mountain range, Sonora. In the United States they have been reported in Texas (Shale Mingus, Strawn Group, Training Thrifty, Training Graham, and Limestone Marble Falls) and Oklahoma (Training Dornick Hills).

Keywords : Crinoidea; Permian; Tuzancoa Formation; Hidalgo; Mexico.

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