Do Pakistan Fossils Alter Path of Lemur Evolution?
Bijal P. Trivedi
for National Geographic Today
|October 22, 2001|
Scientists have discovered what they believe is the oldest known lemur
fossils in the Bugti Hills of central Pakistan. The finding is
controversial because the new evidence suggests that lemurs originated
in Asia, not in Africa as commonly believed.
The fossil remains consist of a collection of tiny teeth that resemble the teeth of Madagascar's modern dwarf lemur, Cheirogaleus. The 30-million-year-old fossils predate all lemur fossils found in Africa. Lead scientist Laurent Mariveux, of Universite Montpellier, in France, said the find was "totally unexpected."
The team dubbed the new lemur Bugtilemur mathisoni. The findings are published in the October 19 issue of the journal Science.
Today lemurs live primarily in Madagascar and some nearby islandsit is thought that they may have migrated to the islands on floating vegetation. The question now is where did the migration begin?
Geological evidence shows that Madagascar separated from India about 88 million years ago, long before the origin of lemurs about 62 million years ago, making Asia an unlikely point of origin.
Mariveux admits the solution to this enigma is still in the future. But he says, "the time has come for the Asian scenario to receive more serious attention."
But some scientists have more fundamental disputes with Mariveux's work. They question whether these teeth really belong to a lemur.
The trademark feature of a lemura tooth "comb", which juts out on the lower jawwas not among the fossils discovered by the team.
"There isn't enough evidence to determine whether this is, or is not a lemur," says William Hylander, director of the Duke University Primate Center in Durham, North Carolina.
A more likely explanation, says paleontologist Richard Kay, also of Duke University, is that the fossil teeth belong to a family of Eurasian primatessivaladapisthat are now extinct. The sivaladapis family of primates which lived in India about 13 million years ago have similar teeth to lorises, a close relative of the lemur, but the two are unrelated.
Mariveux's new finding departs radically from mainstream opinion, which doesn't mean that it is wrong, says Kay, it just needs more support.
Suggesting that the fossilized teeth belong to a lemur is "an extraordinary claim," says Kay. "It demands extraordinary evidence."
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