A small, lemur-like creature may have been an early ancestor of monkeys, apes, and humans. A magnificently preserved fossil dating from 47 million years ago reveals an animal that had, among other things, opposable thumbs, similar to humans’ and unlike those found on other modern mammals. It has fingernails instead of claws. And scientists say they believe there is evidence it was able to walk on its hind legs [ABC News].
In a study that will be published in the journal PLoS ONE tomorrow, researchers will report that this extraordinary fossil could be a “stem group” from which higher primates evolved, “but we are not advocating this” [The New York Times]. The fossil was first discovered in 1983 in the Messel Shale Pit, an old quarry near Frankfurt, Germany that has long been a World Heritage Site because of its rich fossil beds. The specimen was excavated by private collectors but was then divided into two parts and sold; it was only two years ago that scientists reassembled the complete fossil and began studying it.
Described as the “most complete fossil primate ever discovered,” the specimen is a juvenile female the size of a small monkey. Only the left lower limb is missing, and the preservation is so remarkable that impressions of fur and the soft body outline are still clear. The animal’s last meal, of fruit and leaves, remained in the stomach cavity [The New York Times]. The fossil will be unveiled with much pomp and ceremony at the American Museum of Natural History tomorrow, and the History Channel will air a documentary about the find next week. In a final element of the media blitz, a Web site has been launched with full details about the primate fossil, which researchers have nicknamed “Ida.”
The new research adds to an argument over which of two groups of ancient primates was the evolutionary jumping off point for apes and humans: Was it the tarsidae group, which gave rise to the big-eyed tarsiers found in southeast Asia, or the adapidae group, the precursors of the lemurs found in Madagascar? The latest discovery bolsters the less common position that our ancient ape-like ancestor was an adapid, the believed precursor of lemurs…. “This discovery brings a forgotten group into focus as a possible ancestor of higher primates” [The Wall Street Journal], says study coauthor Philip Gingerich.
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Image: The Link / Atlantic Productions
May 18th, 2009 at 2:17 pm
are there pics?
May 18th, 2009 at 2:18 pm
So this ancestor walked upright, that means human ancestors adopted a more all fours posture, then re-evolved a trait that we may have already carried genetically? crazy.
May 18th, 2009 at 4:09 pm
Chris: There will be pics tomorrow! But only after the fancy press conference gets held. I’ll probably post a photo then.
Jumblepudding: I don’t think it walked on its hind legs habitually — I’m guessing it could just rear up and take a few steps. When I get more detailed info I’ll let you know.
May 19th, 2009 at 10:29 am
The scientific article on which this story is based is available to read for free, in the peer-reviewed Open Access journal, PLoS ONE, at: http://dx.plos.org/10.1371/journal.pone.0005723
May 19th, 2009 at 12:00 pm
I have a video of one; magnificent creature. Just magnificent.
May 20th, 2009 at 11:52 am
Thanks for the updated article link, PLosONE. (Is that you, @BoraZ?)
May 23rd, 2009 at 4:49 pm
Can’t wait to see the dna. We could be calling something that looks like a house cat with thumbs Mom!
May 27th, 2009 at 12:26 am
Unfortunately the authors of the study have grossly misinterpreted this beautiful and important find. Many, many adapid fossils are known from the Eocene and have been intensively studied for over a century. All lack a toothcomb and most lack a grooming claw. This is not news and totally expected. They all have opposable thumbs and big toes, which are basic primate traits. The talus shape is seen in all anthropoids (monkeys, apes and humans) and has nothing to do with bipedalism. It is also seen in Asian primates from the same time which have more visible anthropoid traits called eosimiids. The authors look at the specimen as if in a vacuum. Their biased research will only serve to discredit the true value of this specimen.
May 27th, 2009 at 6:02 pm
I find the whole thing a bit “fishy”. I love this kind of science but I coulden’t finish watching the special. It is just too weird.