About 13 million years ago, when present-day Kenya was covered in forests, a baby ape died. Its tiny corpse was covered in ash from a nearby volcano, helping to perfectly preserve its fragile cranium. Now, reports Michael Greshko at National Geographic, that baseball-sized skull is giving researchers insight into a little understood period when the human and ape lineages split.
As Greshko reports, between 25 to 28 million years ago, apes diverged from Old World monkeys before splitting into many different lineages. While most of those evolutionary branches died off about 7 million years ago as the climate changed, one line remained, later branching into great apes, like chimps, gorillas and eventually humans. Reconstructing the history of that branch, however, has been difficult, mainly because the forests those common ancestors once lived weren’t great at preserving fossils. Researchers have found bits of jaw, facial bones and foreheads, but a complete cranium is an almost miraculous find.
During an expedition three years ago, Kenyan fossil hunter John Ekusi discovered the infant skull in the Turkana Basin of northern Kenya, reports Michael Price at Science. Dating suggests that the skull was some 13 million years old and dental rings showed the creature was just one year, four months old when it perished. The shape of the teeth also showed it was a new species in the genus Nyanzapithecus, given a species designation of alesi. The research appears in the journal Nature.
Read more: https://www.smithsonianmag.com/smart-news/baby-animal-may-be-last-common-ancestor-humans-and-apes-180964469/