Monkeys crossed Atlantic on driftwood rafts
Undiscovered species made journey from Africa to America 34 million years ago, scientists reveal
MONKEYS made a 900-mile ocean journey on driftwood from Africa to the Amazon 34million years ago, according to a study.
Four tooth fossils of a newly discovered species of parapithecid primate have been discovered in the Peruvian Amazon, according to an article in the journal Science.
The extinct monkeys originated in Africa, and researchers at the University of Southern California say they most likely resembled modern marmosets in size.
Fossils discovered at the same site in Peru had earlier provided the first proof that South American monkeys evolved from African primates.
Scientists say the transatlantic journey was likely to have been made at around the time a major drop in sea levels would have made the ocean voyage shorter. At the time, South America was an island continent and the only way the monkeys could have arrived in the Amazon from Africa was by sea.
They are thought to have crossed the ocean on floating rafts of vegetation that broke off from coastlines, possibly during a storm, and a favourable current took them to the Amazon.
Prof Erik Seiffert, the study’s lead author, said: “This is a unique discovery. It shows that in addition to the New World monkeys and a group of rodents known as caviomorphs, there is this third lineage of mammals that somehow made this very improbable transatlantic journey to get from Africa to South America.”
The monkeys have been named Ucayalipithecus perdita, from Ucayali, the area where the teeth were discovered, pithikos, Greek for monkey, and perdita, Latin for lost.
Prof Seiffert said: “We’re suggesting that this group might have made it over to South America right around what we call the Eocene-oligocene Boundary, a time period between two geological epochs when the Antarctic ice sheet started to build up and the sea level fell.
“That might have played a role in making it a bit easier for these primates to actually get across the Atlantic.”
He said two of the fossilised teeth were identified by Argentine co-authors of a study in 2015 showing New World monkeys had African ancestors.
When Prof Seiffert was asked to help describe the specimens in 2016, he noticed the similarity of the two broken upper molars to an extinct parapithecid monkey species from Egypt he had studied previously. An expedition to the Peruvian fossil site in 2016 led to the discovery of two more teeth belonging to the new species.
The resemblance of the additional teeth to those of the Egyptian monkey confirmed to Prof Seiffert that Ucayalipithecus had African ancestors.
He added: “The thing that strikes me about this is just how improbable all of it is. The fact that it’s this remote site in the middle of nowhere, that the chances of finding these pieces is extremely small, to the fact that we’re revealing this very improbable journey that was made by these early monkeys, it’s all quite remarkable.”