by Tom Parisi
NIU anthropologist Dan Gebo is part of a small team of paleontologists who have received a grant of $350,000 from the National Science Foundation to continue expeditions in northern China in their quest to find primate origins.
Gebo is a world renowned expert on the biomechanics and evolution of primates. He and colleagues Christopher Beard of Carnegie Museum of Natural History in Pittsburgh and Meng Jin of the American Museum of Natural History in New York traveled to China this summer for the first of three field seasons funded by the NSF grant.
“Human evolution clearly started in Africa, but we’re looking for primates in a much earlier time period, long before humans appeared on the planet,” Gebo says. “We’re basically trying to find the oldest primates on record. Most people think primates originated in Africa, but we believe the fossil record suggests that the origin and early evolution of primates may have been confined to Asia. That’s why we’ve spent the last 10 years working there.”
Very little is known about primate evolution during the Paleocene Epoch – 65 to 55 million years ago. The Paleocene was a warm period on the planet, when rainforest animals would have been highly mobile and capable of crossing land bridges to other northern continents.
“There were no ice caps at this time,” Gebo says. “In the Arctic Circle, there were actually rain forests.”
The oldest primate evidence on record is generally believed to be a fossil recovered in Morocco. It could be in excess of 55 million years old, but there is some ambiguity over its age. Gebo said he and his colleagues have identified a single fossil tooth from China that is likely as old.
“It might even be older,” he says. “We can only date our fossil by looking at the fossils of other animals in the stratified section of rock where it was recovered.”
The researchers are focusing their work on sites in northern China, where the age of the sediment corresponds with the Paleocene. This past summer’s fieldwork yielded a number of fossils but no primate bones, Gebo said.
Fossils of Paleocene-era primates are particularly difficult to find because they were diminutive creatures. In 2000, Gebo led a research team that announced the fossil discovery of 45 million-year-old, thumb-length primates. Recovered from the fissure-filled sediments of a limestone quarry in China, the fossils represent the smallest known primates, with one species estimated to have weighed only 10 grams.