Pliocene and Pleistocene Vertebrates of New Mexico


Link to Full Text

Download Full Text

Publication Date

January 2015


New Mexico has a diverse record of Pliocene and Pleistocene vertebrates, including faunas from all three North American land-mammal "age"s (NALMAs) that occur within those two epochs (Blancan, Irvingtonian, and Rancholabrean), between 4.9 million (Ma) and 10 thousand (ka) years in age. There are 246 named Pliocene and Pleistocene vertebrate faunas from New Mexico: 40 Blancan, 19 Irvingtonian, and 187 Rancholabrean. The Blancan and Irvingtonian faunas are mostly open sites, derived from strata of the Santa Fe Group in the Rio Grande valley that bisects the state from the Colorado border on the north to the Texas and Mexico borders on the south. There are also several Blancan faunas from strata of the Gila Group in the Gila River valley in southwestern New Mexico. There are two diverse lrvingtonian cave faunas from New Mexico, San Antonio Mountain (SAM) Cave in northern New Mexico near the Colorado border and Slaughter Canyon Cave in Carlsbad Caverns National Park in the southeastern part of the State. Rancholabrean vertebrate faunas occur throughout the state, with at least one site in each of New Mexico's 33 counties. Concentrations of Rancholabrean sites in New Mexico are found in the Southern High Plains in the eastern part of the State; lacustrine deposits, including Pleistocene Lake Estancia, Pleistocene Lake Otero, and Pleistocene Lake San Agustin; gravel pits in the Rio Grande and Pecos River valleys: and caves in the mountain ranges in the southern counties, particularly the Guadalupe Mountains in Eddy County. Blancan vertebrate faunas from New Mexico are separated into the late early Blancan (~3.6-2.7 Ma), early late Blancan (~2.7-2.2 Ma), and latest Blancan (~2.2-1.6 Ma). Late early Blancan faunas include: Mesa del Sol, Bernalillo County; Arroyo de la Parida, Socorro County; Cuchillo Negro Creek, Elephant Butte Lake, and Truth or Consequences, Sierra County; Tonuco Mountain, Doña Ana County; and Buckhorn; Grant County, Early late Blancan faunas include: Santo Domingo, Sandoval County; Palomas Creek, Sier