Myanmar fossil may shed light on evolution
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Myanmar fossil may shed light on evolution
By MICHAEL CASEY – 19 hours ago
BANGKOK, Thailand (AP) — 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.
"This new fossil Ganlea definitely helps us argue — and we think the
argument is pretty close to settled now — that when you go back this
far in time, the common ancestor of monkeys, apes and humans was
definitely in Asia, not in Africa," Beard said.
In May, researchers unveiled a nearly intact skeleton of a 47 million-
year-old primate, found in Germany and dubbed "Ida," that they said
provides a glimpse into how our distant ancestors may have looked.
Jorn Hurum, who brought Ida to the University of Oslo Natural History
Museum, that it was too early to draw conclusions from the Myanmar
fossils because only jawbones and teeth were found.
"These fragments are still too few and far between," Hurum said. "This
is the kind of scientific debate that will continue until more
complete skeletons like Ida has been found, and this may take several
hundred years."
Professor Colin Groves, a primate expert from the Australian National
University's School of Archaeology & Anthropology argued it was wrong
to rule out Africa altogether because of the dearth of good dig sites
on the continent from that period.
"There are no sites of comparable age in Africa ... so we just can't
tell what the real locus of anthropoid evolution at this time was,"
Groves told the Associated Press in an e-mail. "It could still have
been Africa (but) most likely these proto-anthropoids were widespread
throughout the old world tropics."
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