Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto Gliptodontes pleistocénicos del Centro de México 267 ResumenTrabajo paleontológico realizado en la región centro-meridional de Hidalgo, permitió recuperar una muestra importante de restos pertenecientes a Glyptodontidae. El material se recuperó de una secuencia sedimentaria innominada que consiste en arcillas, limos y gravas de pobre a moderadamente consolidadas de origen fluviolacustre; los ejemplares están asociados a restos de bisonte (Bison), que sugiere una antigüedad asignable al Rancholabreano. La muestra incluye tres fragmentos de coraza y 10 osteodermos aislados. Los osteodermos son hexagonales con dos a cinco folículos pilosos, la figura central es poligonal, cóncava y ligeramente sobreelevada; alrededor de la figura central existen de ocho a nueve figuritas periféricas dispuestas de manera simétrica y configuración burdamente trapezoidal. El patrón de la roseta corresponde al observado en Glyptotherium floridanum y, por lo tanto, es que los ejemplares hidalguenses se asignan a esta especie. En México,
A new species of gopher, Gregorymys mixtecorum n. sp., is described from the Arikareean 1 (early Oligocene) of Oaxaca, southern Mexico. Phylogenetic analysis indicates that it is the sister species of G. veloxikua, which was also recently described from southern Mexico. Both species were collected from sediments of the Chilapa Formation that crop out in northwestern Oaxaca. Gregorymys mixtecorum n. sp. and G. veloxikua show differences in size and proportions that possibly reduced competition for resources, exploiting different microhabitats. Both Mexican species represent the oldest and the most southern records of Gregorymys in North America. The Mexican record of Gregorymys suggests that at least some entoptychine rodents diversified in southern Mexico or Central America, and that Geomyidae has had a wide geographic distribution in North America since the early Oligocene. UUID: http://zoobank.org/0f4ad549-2f59-442b-87fa-5c9be0573ea4
Las áreas protegidas juegan un papel central en la conservación, por lo que es importante conocer cómo los criterios para su selección y establecimiento se han modificado a través del tiempo. Se presentan los estudios de caso de tres países de América, EUA, México y Costa Rica, analizando tres momentos de su historia, desde el establecimiento de las primeras Áreas Naturales, seleccionadas por características cualitativas, hasta la consolidación de metodologías sistemáticas actuales.
Paleontological work carried out during the past years in the late Pleistocene (Rancholabrean) localities of Hidalgo, Puebla and Oaxaca states allowed the recovery of an important sample of proboscidean specimens, which consists of skull fragments, teeth, and several postcranial bones, collected from fluviolacustrine sediments. This material was identified as Mammuthus columbi. Based on tooth position and the estimated age in African elephant years, the sample studied represents 15 or 16 individuals; seven or eight from Oaxaca, and at least four from each locality of Puebla and Hidalgo. The best-represented age category is that of mature adults (≥ 30 years), followed by adolescents (3 to 17 years). Lamellar frequency (≤ 5) and enamel width (≥ 2.4 mm) indicate the presence of at least one adult male sexually mature in each of the Mexican states from where the specimens were recovered. On the other hand, the microwear analysis of some of the individuals studied showed a higher number of scratches compared to the pits and a high frequency of wide scratches. This microwear pattern is indicative of a mixed-feeding dietary habit with a high proportion of abrasive resources intake. Indirectly, the mixed-feeder condition of these M. columbi individuals indicates the presence of open areas, probably covered with grasses, bushes and herbs and closed-vegetation areas (with trees), in what now is the southeastern portion of Hidalgo, the Valsequillo basin in Puebla and the Mixteca Alta in Oaxaca during the late Pleistocene.
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