New Fossil Primate Suggests Common Asian Ancestor, Challenges Primates Such As 

The discovery of this new fossil primate from Myanmar (previously known as
Burma) suggests that the common ancestor of humans, monkeys and apes
evolved from primates in Asia, not Africa as many researchers believe.
(Credit: Mark A. Klingler/Carnegie Museum of Natural History)
ScienceDaily (July 1, 2009) - 

A new fossil primate from Myanmar (previously known as Burma)
suggests that the common ancestor of humans, monkeys and apes evolved
from primates in Asia, not Africa as many researchers believe.
A major focus of recent paleoanthropological research has been to
establish the origin of anthropoid primates (monkeys, apes and humans)
from earlier and more primitive primates known as prosimians (lemurs,
tarsiers and their extinct relatives). Prior to recent discoveries in
China, Thailand, and Myanmar, most scientists believed that anthropoids
originated in Africa. Earlier this year, the discovery of the fossil
primate skeleton known as "Ida" from the Messel oil shale pit in
Germany led some scientists to suggest that anthropoid primates evolved
from lemur-like ancestors known as adapiforms.

According to Dr. Chris Beard, a paleontologist at Carnegie Museum of
Natural History in Pittsburgh, Pennsylvania and a member of the
international team of researchers behind the Myanmar anthropoid
findings--the new primate,Ganlea megacanina, shows that early
anthropoids originated in Asia rather than Africa. These early Asian
anthropoids differed radically from adapiforms like Ida, indicating that Ida is 
more closely related to modern lemurs than it is to monkeys, apes and humans.

The 38-million-year-old Ganlea megacanina fossils,
excavated at multiple sites in central Myanmar, belong to a new genus
and species. The name of the new species refers to a small village,
Ganle, near the original site where the fossils were found, and the
greatly enlarged canine teeth that distinguish the animal from closely
related primates. Heavy dental abrasion indicates that Ganlea megacanina used
its enlarged canine teeth to pry open the hard exteriors of tough
tropical fruits in order to extract the nutritious seeds contained

"This unusual type of feeding adaptation has never been documented
among prosimian primates, but is characteristic of modern South
American saki monkeys that inhabit the Amazon Basin," says Dr. Beard. "Ganlea 
shows that early Asian anthropoids had already assumed the modern ecological 
role of modern monkeys 38 million years ago."

Ganlea and its closest relatives belong to an extinct
family of Asian anthropoid primates known as the Amphipithecidae. Two
other amphipithecids, Pondaungia and Myanmarpithecus, were previously
discovered in Myanmar, while a third, named Siamopithecus, had been
found in Thailand. A detailed analysis of their evolutionary
relationships shows that amphipithecids are closely related to living
anthropoids and that all of the Burmese amphipithecids evolved from a
single common ancestor. Some scientists had previously argued that
amphipithecids were not anthropoids at all, being more closely related
to the lemur-like adapiforms.

The discovery of Ganlea strongly supports the idea that
amphipithecids are anthropoids, because adapiforms never evolved the
features that are necessary to become specialized seed predators.
Indeed, all of the Burmese amphipithecids appear to have been
specialized seed predators, filling the same ecological niche occupied
by modern pitheciine monkeys in the Amazon Basin of South America.
During the Eocene when Ganlea and other amphipithecids were living in
Myanmar, they inhabited a tropical floodplain that was very similar to
the environment of the modern Amazon Basin.

Fossils of Ganlea megacanina were first discovered in
Myanmar in December 2005. The fieldwork is a long-term collaboration by
scientists from several institutions in Myanmar; as well as the
University of Poitiers and the University of Montpellier in France;
Carnegie Museum of Natural History in Pittsburgh, PA; and the
Department of Mineral Resources in Bangkok, Thailand. Funding was
provided by the U.S. National Science Foundation and the Centre
National de la Recherche Scientifique in France.


Story Source:
Adapted from materials provided by Carnegie Museum of Natural History. 

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