Add two new species of 'gibbon and monkey' to the evolutionary tree

Scientists have unearthed fossil samples of gibbons and ancient world monkeys (Old World Monkeys) in the riverbed in Tanzania.

The fossil found includes a molar tooth belonging to the new species Nsungwepithecus, the oldest member of the group of primates including cercopithecoids. The team also found a piece of jaw bone, consisting of a molar tooth and three molars, which is thought to belong to the new genus Rukwapithecus, the first member of the hominoids group, which contains species of wild animals (gorillas, chimpanzees. , bonobo, orangutans and even humans) and lower than monkeys (gibbons).

The picture outlines two new species: Rukwapithecus (left) and the world ancient monkey Nsungwepithecus (right) - (Photo: LiveScience)

Researchers estimate that Rukwapithecus weighs about 12kg. Because Nsungwepithecus's fossil is fragmented, its size is difficult to predict, but may be slightly smaller than Rukwapithecus.

The fossil remains of these two new primates were 25 million years ago, filling the gap in fossil data, revealing the first time when gibbons and monkeys began to separate.

"This finding is important because it provides the first fossil evidence for one of the primates , " said Nancy Stevens, lead researcher, anthropologist at Ohio University in Athens. '.

DNA evidence has long suggested that old world gibbons and monkeys separated from a common ancestor 25-30 million years ago. But so far no fossils larger than 20 million years have been found.

The age of the new specimen extended the origin of the old world of gibbons and monkeys into the Oligocene era, which lasted from 23 to 34 million years ago. Previously, only three primates were known in the global Oligocene era, Stevens said.