One of the ways we know about the behavioral capabilities of Neanderthals and Denisovans is through the stone tools they left behind — the artifacts that survive in the archaeological record long after the organic material has decayed.

Denisova Cave has yielded an extraordinary assemblage of stone tools spanning the entire long history of its occupation.

The lower levels — the oldest — contain tools characteristic of the Middle Paleolithic, the technological tradition associated primarily with Neanderthals across the Old World.

These are relatively standardized flake tools, prepared cores, scrapers and points of the type known as Mousterian after the French site where this technology was first formally described.

The upper levels — the younger — contain tools of the Upper Paleolithic, a more diverse and technologically innovative tradition associated with modern humans (and, in some cases, with late Neanderthals).