Chororapithecus abyssinicus was an ape that lived about 10 to 10.5 million years ago during the Miocene Epoch. It is believed to be the earliest known species of gorilla. Its existence indicates that the last common ancestor between the human/chimpanzee lineage and gorillas may have lived greater than 10 to 11 million years ago, which is at least 2 million years earlier than the previously thought date of divergence of about 8 million years ago.
The only evidence found of this extinct ape is currently nine Fossilized teeth of at least three individuals, recovered from the Chorora Formation which runs along the southern Afar Depression of Ethiopia (the same place where the remains of Lucy were discovered in 1974). Analysis of eight molars (two of them fragmented) and a canine tooth show that their structure is partly similar to modern gorillas.
The researchers compared the makeup of the teeth to other current and fossil apes, and concluded that the new ape fossils possibly were a species of gorilla which ate mostly high-fiber plants, and that the fossil species is likely a 'direct ancestor' of the gorillas that currently live in Africa. Alternatively, the idea that the finds are the remains of early hominins has not been ruled out entirely.