: Missing link’ primate likely to stir debate

Message Share Topic Printable Version Google Delicious Digg StumbleUpon Windows Live Yahoo Bookmarks reddit Facebook MySpace Newsvine Furl Topic Search Topic Options Post Reply Create New Topic

   A discovery of a 47 million-year-old fossil primate that is said to be a human ancestor was announced and unveiled Tuesday at a press conference in New York City. 

Known as "Ida," the nearly complete transitional fossil is 20 times older than most fossils that provide evidence for human evolution. 

It shows characteristics from the very primitive non-human evolutionary line (prosimians, such as lemurs), but is more related to the human evolutionary line (anthropoids, such as monkeys, apes and humans), said Norwegian paleontologist Jørn Hurum of the University of Oslo Natural History Museum. However, she is not really an anthropoid either, he said.
The fossil, called Darwinius masillae and said to be a female, provides the most complete understanding of the paleobiology of any primate so far discovered from the Eocene Epoch, Hurum said. An analysis of the fossil mammal is detailed Tuesday in the journal PLoS ONE. 

"This is the first link to all humans ... truly a fossil that links world heritage," Hurum said.

Here is some context for the age of the new primate fossil: Anatomically modern humans (Homo sapiens) first emerged about 200,000 years ago, but early humans such as Australopithecus afarensis and Australopithecus anamensis reach back 3 million to 4 million years ago or even earlier. Humans are thought to have split off from a group that includes chimpanzees and gorillas about 6 million years ago. And a group that includes all the great apes (including us) and Old World monkeys (called simians or anthropoids) diverged from New World monkeys in the Eocene, just after the time of Ida. So our primate roots reach back to this time. 

Ida was preserved in Germany’s Messel Pit, a mile-wide crater containing oil-rich shale that is a significant site for fossils of the Eocene Epoch. Opposable big toes and nail-bearing tips on the fingers and toes confirm that the fossil is a primate, and a foot bone called the talus bone links Ida directly to humans, Hurum said.

The fossil also preserved the primate's gut contents, including fruits, seeds and leaves. X-rays reveal both baby and adult teeth, plus the lack of a "toothcomb" or a "grooming claw," which is an attribute of lemurs (which are also primates, like us, but are considered more primitive and part of a family different from great apes and us).

(Very interesting the part about the feet of Ida, more to the human line then to the lumers line)

http://www.msnbc.msn.com/id/30826552/?GT1=43001 

Edited by docyabut - 28-May-2009 at 13:07