Scientists say a 47-million-year-old fossil found in Germany may be a key link to explaining the evolution of early primates and, perhaps, telling them about developments that led to modern human beings.
The fossil, of a young female that probably resembled a modern-day lemur, is described as "the most complete primate fossil ever found." It is small -- its body is about the size of a raccoon -- but it has characteristics found in later primates and in humans.
"We realized, when I was offered this specimen," said Dr. Jorn Hurum of the University of Oslo, who led the two-year effort to determine the fossil's importance, "that it was the most complete primate in the fossil record."
The fossil was unveiled today amid great fanfare at a news conference at the American Museum of Natural History in New York City. Hurum nicknamed it "Ida," after his own six-year-old daughter.
It has, among other things, opposable thumbs, similar to humans' and unlike those found on other modern mammals. It has fingernails instead of claws. And by examining the structure of its hind legs (one of which is partly missing), scientists say they can see evidence of evolutionary changes that would eventually lead to primates standing upright.
A detailed description of the fossil is being published today in the online journal Public Library of Science - One (PLoS One for short). The cable channel History, which bought the North American documentary rights to the find, provided exclusive material to ABC News, although many details were kept under wraps until today.
"She is a transitional species showing characteristics from both the non-human (prosimians and lemurs) and human (anthropoids, monkeys, apes and man) evolutionary lines," said the producers in a statement reviewed by the authors of the PLoS One paper.
The unveiling was part of a large publicity campaign by History, which plans to show its documentary, "The Link," on Monday night. There is a companion book from Little Brown, as well as a Web site. New York City Mayor Michael Bloomberg made an appearance at the news conference. The fossil will be shown on "Good Morning America" Wednesday.
But there was a divide between the documentary producers and the scientists over the importance of the find.
"In this time of economic hardship, it is nice to turn to another time, 47 million years ago, to the story of a little girl, who possibly connects to us," said Anthony Geffen of Atlantic Productions, which produced the documentary.
But Jens Franzen of the Senckenberg Research Institute in Germany, who was on the team assembled to examine the fossil, said, "I don't think so, that we are dealing with a direct ancestor.
"We are not dealing with our grand, grand grandmother, but perhaps with our grand, grand, grand aunt."
In response to a reporter's question, Hurum also agreed it would be hard to call "Ida" a direct human ancestor. But he said he was comfortable with the publicity surrounding it.
"That's part of getting science out to the public, to get attention," he said. "I don't think that's so wrong."