July 22, 2010

Ancient Monkey Fossil Found In Underwater Cave

Scientists have examined the fossilized remains of a small, extinct monkey that were recovered from an underwater cave in the Dominican Republic.

Researchers believe the fossil is about 3,000 years old, but say the species itself could be very ancient. The find reveals clues about the origin of primates in the region.

Dr Alfred Rosenberger from Brooklyn College in New York, led the examination of the monkey's bones. The results of the assessment are published in the Royal Society of Proceedings B.

Rosenberger explained that the bones, which included a near complete skull, were found by a team of scuba divers who were exploring an underwater cave in the area. He said it is "miraculous that they even saw it."

"When they discovered it, they were fearful the bones were exposed, so they moved the material to a little nook to protect it," he told BBC News.

After gaining approval to remove the remains from the cave, Rosenberger returned to the cave with the scuba divers to retrieve it in October of last year.

Divers packed the fossil in watertight food-storage boxes in order to bring it safely to the surface.

Dr Rosenberger said the monkey, which is only the second specimen of the species Antillothrix bernensis ever found, probably measured about 12 inches from head to toe.

The examination revealed some surprising finds.

"Its femur or thigh bone was very thick. So it had sort of stout legs, which is something we didn't expect," Rosenberger said, adding that "we don't really have any living examples of New World monkeys that have stout legs like that."

The monkey may have behaved similarly to a koala bear -- clinging to tree trunks, rather than leaping from branch to branch. Although, "that's a very rough analogy," he said.

The fossil adds evidence that there were several lineages of primates in the Caribbean, instead of one ancestor that moved into the region millions of years ago. It is likely that several species made the journey "over the water" to inhabit the island of Hispaniola.

"And even though these particular bones might be relatively young, we're pretty sure that the arrival of these animals occurred well over 10 million years ago," Rosenberger added.

"That's an exciting part of the story - if you compare the dental remains of our monkey to other fossils that we know of, we see strong similarities with Patagonian fossils that are around 15 million years old."

The Caribbean islands have experienced the world's highest level of extinction in mammals over the last 10,000 years.


Image Caption: The Antillothrix bernensis skull shown in several views.


On the Net: