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Boletín de la Sociedad Geológica Mexicana Volumen 72, núm. 2, A280819, 2020 |
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Columnar ossicles of Permian crinoids, including two new genera, from the Grupera Formation (Asselian–Sakmarian) of Chiapas, Mexico
Osículos columnares de crinoideos pérmicos, incluidos dos géneros nuevos, de la Formación Grupera (Asseliano–Sakmariano) de Chiapas, México
Miguel A. Torres-Martínez1,*, Rafael Villanueva-Olea2, Francisco Sour-Tovar3
1 Departamento de Paleontología, Instituto de Geología. Universidad Nacional Autónoma de México, Circuito de la Investigación Científica, Avenida Universidad 3000, Coyoacán, 04510, Mexico City, Mexico.
2 Departamento de Biología Evolutiva, Facultad de Ciencias. Universidad Nacional Autónoma de México, Circuito Interior, Avenida Universidad 3000, Coyoacán, 04510, Mexico City, Mexico.
3 Museo de Paleontología, Facultad de Ciencias. Universidad Nacional Autónoma de México, Circuito Interior, Avenida Universidad 3000, Coyoacán, 04510, Mexico City, Mexico.
* Corresponding author: (M.A. Torres-Martínez) This email address is being protected from spambots. You need JavaScript enabled to view it.
How to cite this article:
Torres-Martínez, M. A., Villanueva-Olea R., Sour-Tovar, F., 2020, Columnar ossicles of Permian crinoids, including two new genera, from the Grupera Formation (Asselian‒Sakmarian) of Chiapas, Mexico: Boletín de la Sociedad Geológica Mexicana, 72 (2), A280819. http://dx.doi.org/10.18268/BSGM2020v72n2a280819
Abstract
Eleven morphotypes of columnar ossicles of Permian crinoids collected from the Grupera Formation (Asselian‒Sakmarian) are described. Floricyclocion heteromorpha and Cyclogrupera minor are proposed as new morphogenera and morphospecies. Preserved elements allow relating the depositional paleoenvironment to restricted waters of the inner ramp. The stratigraphical range of Cyclocaudiculus regularis, Heterostelechus keithi, Lamprosterigma erathense and Cyclocaudex insaturatus is extended from the Pennsylvanian (Upper Carboniferous) to the lower Cisuralian (lower Permian). The record of all parataxa studied is the first in Chiapas, Mexico, and the first formal work on Permian crinoids from the Chicomuselo region. Because the specimens were found in a Permian unit that had been related to the Grandian Province of North America (Texas and New Mexico in USA; Coahuila, Sonora and Chiapas in Mexico; and Palmarito in Venezuela), it is suggested that crinoids should be part of the same paleoprovince.
Keywords: Parataxa, Floricyclocion, Cyclogrupera, Asselian‒Sakmarian, Grandian Province.
