Sea level drops help monkeys reach South America

One day 34 million years ago, monkeys used plants grown along the coast to make a bamboo raft, and then jumped on it and drifted into the vast sea. No one knows why they left their homes, but the fossil record tells us that they sailed more than 900 miles - most likely in storms, from Africa to South America.
A new study published April 10 in Science by researchers at the University of Southern California says fossils of four monkey teeth found deep in Peru's Amazon rainforest provide new evidence that more than one group of ancient primates crossed the Atlantic Ocean from Africa.
" is a unique discovery. "The study shows that in addition to the New World monkeys and a group of rodents called Caviomorphs, there is a third mammalian lineage that somehow completes this unlikely transatlantic journey," said study co-author Erik Seiffert, a professor at the University of Southern California's Keck School of Medicine.marc Godinot of France's National Museum of Natural History, who was not involved in the study, said scientists were initially skeptical of the idea that small mammals cross huge ocean barriers and thrive in distant places. But systematic developmental evidence from the 1980s suggests that the New World monkeys and Caviomorphs in the Western Hemisphere originated in the Ococcisttal African-Arab region, so they had to cross the South Atlantic to reach South America.
and surprisingly, more than one animal has overcome the ocean barrier. These newly discovered teeth are similar to those of the ape primate, but belong to a new species. The ape is an extinct high-order primate that lived in North Africa around the 1980s (56 million to 33.9 million years ago) and the Octinate (33.9 million to 23 million years ago).
previously thought to be the only primate living in the New World. Broad-nosed monkeys are one of the two branches of the ape-like crown group, as early as 40 million years ago, the broad-nosed monkeys and other great branches of the apes, including humans - narrow-nosed monkeys - parted ways, the broad-nosed monkeys have since evolved independently.
the teeth found on the left bank of Peru's Yuruá River suggest that another primate linee, unlike the broad-nosed monkey, also lived briefly in the New World. The fossils also provide the first evidence that South American monkeys evolved from African primates.
the site of the discovery of the teeth in Ucayali belongs to the Grady. Based on the age of the site and the close relationship between the monkeys and fossils of Egyptian "relatives," the researchers speculate that the monkeys, which originated in the African sub-ape family, may have come here byacross the Atlantic ocean about 35 million to 32 million years ago, as did the ancestors of the broad-nosed monkeys.2015, the study's Argentine collaborators discovered two exotic tree teeth. When Seiffert was invited to help describe the specimens in 2016, he noticed that the two broken upper teeth were similar to an extinct 32 million-year-old Egyptian ape species he had previously studied.
a 2016 visit to a fossil site in Peru, researchers found two more teeth belonging to the new species. The similarities between these extra lower teeth and those of Egyptian monkeys have convinced Seiffert that the monkeys' ancestors came from Africa.
researchers named the extinct monkey Ucayalipithecus perdita ("The Lost Monkey of Ucayali"). The name comes from the Ucayali region of Peru, where teeth were found, pithikos, which means monkeys in Greek, and perdita, which means lost in Latin.
Seiffert said: "What shocked me was that it was almost impossible. In this remote place, for example, the chances of finding the fragments are very small, and the evidence reveals that these early monkeys made an almost impossible journey, all of which were remarkable. At
, the Atlantic Ocean was narrow - about 1,500 to 2,000 kilometers wide in the South Atlantic - but the water was turbulent. The "Lost Monkey of Ucayali" may be very small, similar in size to that of modern macaques. Analysis suggests that the ancestors of the "Ukayali Lost Monkeys" may have crossed the Atlantic ocean by raft to the New World as sea levels fell in the Atlantic Ocean, but at different times than African broad-nosed monkeys crossed the ocean by raft.researchers say that copees and broad-nosed monkeys must have the extraordinary ability to adapt to harsh conditions in order to survive the sea crossing. Moreover, upon arrival at their destination, these primates must immediately adjust their foraging behaviour to adapt to unfamiliar lands and compete with native species for food and land.
, the monkeys appeared to have survived for at least 11.5 million years, despite their small size. As a result, the researchers believe that these early primates may have a high degree of stress resistance and a variety of behavioral abilities.
but in any case, it's not easy to drift across the sea. The researchers believe the monkeys may have arrived in South America around the 1980s-1900s boundary. This was some time between the two geological times, when the Antarctic ice sheet began to form and sea levels fell. "That's probably one of the reasons why these primates are more likely to cross the Atlantic." Seiffert said.
" rafting across the ocean is an extraordinary feat, especially for some small mammals, which lack the capacity to endure seasonal food shortages. Godinot told China Science, "They also need large rafts, favorable currents, sea level declines, and the possibility of staying on some islands." In fact, for now, only two mammalian populations have crossed the Atlantic In the more than 50 million years since the 1990s. In
, the study helps to understand how the ancestors of these animals shaped one of the most biologically rich regions on Earth. These forests were formed during the Paleo-New Age (66 million to 56 million years ago) and were not affected by inter-ice warming. In contrast, they have experienced a high degree of diversification during these periods. "The study looked at the composition of these forests, where rodents and primates play an important role in seed propagation. Well-preserved Fossils of South American Fruits and Seeds should provide key information about forest composition and plant distribution at the time. Godinot said.
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