B44
Chororapithecus abyssinicus
an 8 million-year-old probable member of the gorilla clade

Although the fossil record of the human linage extends back to 6 to 7 million-years-ago (Ma), few fossils are considered to represent modern great apes or their close ancestors. Here we exhibit fossil teeth of Chororapithecus abyssinicus, named by the authors in 2007, and considered to represent a primitive segment of the gorilla clade. The Chorora Formation sediments have been known since the 1970s, but, prior to our work, only one mammalian fossil-bearing site had been reported. We initiated field research at Chorora and have identified multiple new fossil sites. We have also revised the chronostratigraphy of the Chorora Formation. We now consider the Chororapithecus fossils to be ca. 8 Ma, corroborating the “deep divergence hypothesis” of African ape and human evolution. The Chorora fossils suggest indigenous evolution of many late Miocene sub-Saharan African mammalian lineages/clades, supporting the hypothesis that the African ape and human clade emerged in Africa, and that the gorilla and human lineages had split by ~10 Ma (and humans and chimps by ~8 Ma).　(Gen Suwa)

References

Suwa, G. et al. (2007) A new species of great ape from the late Miocene epoch in Ethiopia. Nature 448: 921–924.

Katoh, S. et al. (2016) New geological and paleontological age constraint for the gorilla-human lineage split. Nature 530: 215–218.