The Japan Times, April 19, 1997

Tree-swinging apes lived earlier than scientists previously believed...

WASHINGTON (AP) The first apes that could reach up and swing from branches made their appearance in Africa more than 20 million years ago, much earlier than previously thought, U.S. scientists reported Thursday.
It was a distant relative of today's apes and humans able to climb after food while the competition was still scrambling about on all fours, the scientists contend in the journal Science.
The 40-to-50-kg animal was the earliest to develop shoulders that would allow it to swing from branches, though it probably moved on all fours when on the ground, the team of scientists said.
Morotopithecus, named for the Moroto area of Uganda where fossil evidence of its existence was found, was closely related to modern apes and humans. "If it wasn't the ancestor, then probably the ancestor was something very like it," said Laura MacLatchy, a member of the research team. There were other animals with generally apelike development at the same time "but they were really different in the way they looked and the way they moved around," MacLatchy said in a telephone interview.
"You don't see anything else like it for another 10 million years, " she said. "We were very excited when we found the shoulder bone—it told us it would have had a lot of shoulder mobility."
Owen Lovejoy, the anatomist who restored parts of the famed Lucy fossil from Africa, said the find provides important information. But he was wary of calling it a common ancestor of apes and humans.
"I put the last common ancestor at about 9 (million years ago) and most people put it more recent than that," he said. The new fossils were dated at 20.6 million years ago.
But the findings were welcomed by other researchers in the field.
"This is certainly the oldest material . . . that shows characteristics of the body skeleton that resemble those of living apes and humans," said Ian Tatersall of the American Museum of Natural History in New York. "This is earlier than anybody thought they would be able to pick up traces of what we see today."
And Richard Potts of the Smithsonian's National Museum of Natural History said the paper fills a major gap in knowledge about early apes. He said scientists have wondered why they had not previously found signs of arm swinging in apes during that time span.
One thing that shoulder mobility would have done, MacLatchy said, was allow the animal to distribute its body weight over different branches, so it could find food in trees unavailable to animals that had to walk atop a single branch.
Other apelike animals of the time would have been walking around on all fours. "If they were in the trees they would have been walking on branches, they wouldn't have been hanging below branches," she said.
The full technical name of the newly found animal is Morotopithecus bishop), for W.W. Bishop, who first discovered some of the fossils more than 30 years ago.
Science is the weekly journal of the American Association for the Advancement of Science.