Original Research ARTICLE
Species diversity and paleoecology of Late Pleistocene horses from southern Mexico
- 1Laboratorio de Paleobiología, Universidad del Mar, Mexico
- 2Museo de Paleontología, Secretaría de Medio Ambiente e Historia Natural, Mexico
- 3Center for Biological Research, Autonomous University of the State of Hidalgo, Mexico
- 4Department of Geoscience and Center for Urban Network Evolution, Aarhus University, Denmark
- 5Instituto de Investigaciones en Ciencias de la Tierra,, Michoacana University of San Nicolás de Hidalgo, Mexico
Equids are among the most common mammals found in faunal assemblages of Late Pleistocene age in Mexico. Much of what is known about the Equus species is the result of studies conducted in central and northern Mexico; much less is known about species in lower latitudes of Mexico. Here we describe three species that inhabited Oaxaca and Chiapas states. The fossil localities are in northwestern and central Oaxaca, as well as the central part of Chiapas. In Oaxaca, the largest species, Equus mexicanus, and the medium-sized Equus conversidens are represented by mandibles, skulls, diverse isolated teeth and some postcranial bones, while the smallest species, Haringtonhippus francisci is represented by a skull fragment and few isolated teeth. In Chiapas, E. mexicanus is represented by a mandible and several isolated teeth, E. conversidens by several mandibles and diverse isolated teeth, and H. francisci by isolated teeth and two mandibles. AMS radiocarbon and uranium dating of some of the equid localities in Oaxaca and Chiapas indicate that they were at least present since approximately 44,000 Cal BP years, they were common around 30,000 Cal BP years, and were still present at the end of the Pleistocene, around 12,000 years ago. The record of H. francisci from Chiapas is the youngest in North America.
A cluster analysis of extended mesowear data and a discriminant analysis showed that Equus conversidens from Chiapas was obligate grazer, whilst the rest of the equids were variable grazers.
Geographic distribution of localities in southern Mexico indicates that during the Pleistocene the equid species moved across the Transvolcanic Belt-Sierra Madre del Sur temperate biogeographic corridor and the Tamaulipas-Central America Gulf Lowlands tropical corridor.
Keywords: Equus, Oaxaca, Chiapas, Pleistocene, Mexico, Paleoecology, Taxonomy, Haringtonhippus
Received: 29 Jan 2019;
Accepted: 04 Oct 2019.
Copyright: © 2019 Jiménez-Hidalgo, Carbot-Chanona, Guerrero-Arenas, Bravo-Cuevas, Holdridge and Israde-Alcántara. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Dr. Eduardo Jiménez-Hidalgo, Laboratorio de Paleobiología, Universidad del Mar, Puerto Escondido, Mexico, firstname.lastname@example.org
MD. Gerardo Carbot-Chanona, Museo de Paleontología, Secretaría de Medio Ambiente e Historia Natural, Tuxtla Gutierrez, Chiapas, Mexico, email@example.com