The site had yielded thousands of artifacts and hundreds of animal bones.

What it had not yielded, in the first years of excavation, was anything from the humans who made and used those artifacts.

Everything that scientists knew about the Yana community came from what they had left behind, not from the people themselves.

That changed when the teeth were found.

What The Teeth Are — And Why They Matter

At some point during the excavations at Yana RHS — in sediment layers dated to approximately 31,000 years ago, corresponding to what researchers estimate as about 31,600 calibrated years before present — excavators found two small teeth.

Milk teeth.