Myanmar fossil may shed light on evolution

BANGKOK, Thailand — Fossils recently discovered in Myanmar could prove that the common ancestors of humans, monkeys and apes — known as anthropoids — evolved from primates in Asia, rather than Africa, researchers contend in a study released Wednesday.

The 38 million-year-old pieces of jawbones and teeth are part of a growing body of evidence that is helping scientists to understand the origin of primates, said Dr. Chris Beard, a paleontologist at the Carnegie Museum of Natural History in Pittsburgh and a member of the team who found the fossils near Bagan in central Myanmar in 2005.

"When we found it, we knew we had a new type of primate and basically what kind of primate it was," Beard said in a telephone interview from Pittsburgh. "It turns out that jaws and teeth are very diagnostic. ... They are almost like fingerprints for fossils like this."

The findings were published in the Proceedings of The Royal Society B, a London-based peer-reviewed journal.

Other scientists not involved in the study said that the findings were significant but that they would not end the debate over the origin of anthropoid (highly developed) primates.

Beard and his team from France, Thailand and Myanmar concluded that the fossils — which they dubbed Ganlea megacanina — came from 10 to 15 individuals of a new species that belonged to an extinct family of Asian anthropoid primates known on Amphipithecidae. Wear and tear found on the canine teeth suggest the tree-dwelling, monkey-like creatures with long tails used their teeth to crack open tropical fruit to get to the pulp and seeds — behavior similar to modern South American saki monkeys that inhabit the Amazon basin.

"Not only does Ganlea look like an anthropoid, but it was acting like an anthropoid 38 million years ago by having this feeding ecology that was quite specialized," Beard said.

His team determined that the fossil was 38 million years old, making it several million years older than any anthropoid found in Africa and the second-oldest discovered in Asia.

In 1994, Beard and his Chinese colleagues found fossilized foot bones of the anthropoid Eosimias — one of the worlds smallest primates — which lived between 40 million and 45 million years ago and roamed ancient rain forest on the eastern coast of China.

Beard said the age of both fossils was the evidence he needed to challenge contentions that anthropoid primates had evolved in Africa, where Lucy, a 3.2 million-year-old fossil, was discovered in 1974.