Anthropologists at the University of Texas at Austin say they’ve discovered a previously unknown species of fossil primate in the Devil’s Graveyard badlands of West Texas.
Researchers say the bones discovered at the site belong to Mescalerolemur horneri, a small lemur-like animal belonging to an extinct primate group — the adapiforms — from the Eocene Epoch about 43 million years ago.
“These Texas primates are unlike any other Eocene primate community that has ever been found in terms of the species that are represented,” said physical anthropologist Chris Kirk. “The presence of both Mescalerolemur and Mahgarita, which are only found in the Big Bend region of Texas…is significant because it provides further evidence of faunal interchange between North America and East Asia during the Middle Eocene.”
Researchers say the fossils show Mescalerolemur was a small primate, weighing only about 13 ounces (370 grams). The fossils’ dental anatomy reveals a close evolutionary relationship with adapiform primates from Eurasia and Africa, including a German fossil primate previously claimed to be a human ancestor.
However, the discovery of Mescalerolemur provides further evidence that adapiform primates like Darwinius are more closely related to living lemurs and bush babies than humans.
Mescalerolemur‘s lower jaws were two separate bones with a joint along the midline, a common trait for lemurs while Mahgarita stevensi, the closest fossil relative of Mescalerolemur, had a completely fused jaw joint like that of humans.
Image: Mescalerolemur horneri's partial right lower jaw (scale = 2 mm).
Credit: University of Texas at Austin