Updated Wed, May 15, 2013 4:55 pm
The discovery of fossils of two previously unknown species is revealing new information about the evolution primates, according to a study led by Ohio University scientists.
The study was published online today in journal Nature.
The fossils, found in the East African Rift Valley, are from two major groups of primates, one that includes apes and humans (hominoids) and the other that includes monkeys (cercopithecoids) like baboons and macaques.
According to the study, the fossils are the oldest found from both groups - dating back 25 million years. The fossils were found at the Rukwa Rift Basin of Tanzania. Rukwapithecus fleaglei is an early hominoid. Nsungwepithecus gunnelli is an early cercopithecoid.
"The late Oligocene is among the least sampled in all of primate evolutionary history, said Nancy Stevens, an associate professor of paleontology at OU's Heritage College of Osteopathic Medicine. "Before these discoveries were reported in Nature there were only three primates species know from the late Oligocene, globally."
The time frame also supports a hypothesis based on DNA analysis about the two groups began to diverge from one another.
Stevens said the team will return to the Rift Valley to continue their research.
"What we find now is only more data can help up resolve all of our questions so we are soon headed back to the field to look for more fossils," she said.