New Primate Species Found In 42 Million-year-old Texas Fossils

Westgate is a professor of earth and space sciences at Lamar and a research associate in the Vertebrate Paleontology Laboratory, Texas Natural Science Center, University of Texas-Austin. He and his research colleagues, Dana Cope, professor of anthropology, College of Charleston, and Chris Beard, curator, Vertebrate Paleontology Section, Carnegie Museum of Natural History, announced their discovery at the annual meeting of the American Association of Physical Anthropologists in Philadelphia, Pa., Thursday, March 29.

Molar, pre-molar and incisor teeth from the new primate genus and three other new primate species were recovered from 42 million-year-old tropical, mangrove palm swamp deposits of the Eocene age Laredo Formation exposed in Lake Casa Blanca International State Park in Laredo.

The association of primate fossils with the skeletal remains of oysters, sharks, rays, giant aquatic snakes and crocodiles, along with mangrove palm fruits and pollen, indicates that the middle Eocene shoreline of the Gulf of Mexico lay 150 miles inland of its present position, Westgate said.

The team is preparing detailed manuscripts describing the new Omomyid primates. One of the spoils of discovering a new species is the opportunity to give it a name. The formal name of the new genus, which means "primate of the coastal lagoons", will be released at publication time, Westgate said.

Omomyids (members of the extinct taxon Omomyidae) lived 34 to 50 million years ago during the Eocene Epoch and were one of two groups of known Eocene primates. The other, adapids, were more lemur-like. Fossils of these Eocene primates have been found in North America, Europe, Asia, and Africa. The Eocene primates are the earliest known primates.

Omomyids had large eye orbits, long grasping fingers and short snouts. They weighed around one kilogram, or close to two pounds and were likely nocturnal, with large eyes for seeing better at night. Like most modern-day primates, the omomyids used their long fingers for climbing. They had small mouths, and it is likely that insects were a part of their regular diet.

The presence of a diverse primate community with four species living on the Texas coast during late middle Eocene time is significant because at that time primate diversity in the northern interior of North America had diminished greatly because of global climatic cooling and uplifting of the Rocky Mountains, Westgate said. The tropical environment on the Texas coast appears to have allowed primates to thrive locally while their relatives in the continental interior faced near extinction.

Lamar University, the University of Texas Geology Foundation, the National Geographic Society and the Geological Society of America provided funds for field excavations in Laredo.