It required shelter.

The wooden components of any structure they built would not survive on the open terrace unless protected by permafrost, and the evidence for the nature of their habitations is limited.

But they were there, through multiple seasons, processing enormous quantities of animal remains.

They had shelter of some kind.

It required social organization.

You do not hunt mammoths alone.

The coordination of a mammoth hunt — the communication, the planning, the execution, the butchering and processing of an animal that can weigh six tons — requires multiple people working together with shared purpose and shared knowledge.

The community at Yana was large enough and organized enough to take on the largest prey animals in their ecosystem.