Feeding habits and habitat of herbivorous mammals from the Early–Late Hemphillian (Miocene) of Costa Rica

Carbon and oxygen stable isotope values in the dental enamel of fossils were used to infer the diet and habitat of the extinct equids Calippus hondurensis, Dinohippus mexicanus, and Protohippus gidleyi, the gomphothere Gomphotherium hondurensis, and the llama Hemiauchenia vera of the Early–Late Hemphillian (Hh2) from San Gerardo de Limoncito, Puntarenas province, Costa Rica. The results suggest that these mammals fed mainly on C3 plants and lived in clearings of rainforests. This contrasts with previous studies from North America that indicated that the same species lived in forest savannas and fed mainly on C4 plants, but it is similar to the results obtained from the palynological record of the area, as well as with several vegetation models suggesting the presence of humid tropical forest during the Miocene in Central America

QUERCUS CORRUGATA HOOKER (FAGACEAE) COMO INDICADOR PALEOCLIMÁTICO DEL PLEISTOCENO DE COSTA RICA

Se describen 21 muestras de improntas de frutos fósiles de Quercus corrugata Hooker,procedentes de un yacimiento de travertino de la localidad de La Palmera de San Carlos, cuya altura se ubicaentre los 200 y 400 m sobre el nivel del mar. Se asume una edad Pleistoceno Superior para este yacimiento, envista de que se considera la máxima glacial, comprendido entre 50 000 a 13 000 años antes del presente, comoel mecanismo causante de la migración de esta especie a tales alturas