Them Bone, Them Bones, Them Dry Bones...

I just watched a matched pair of amazing _Nova_ episodes on Neanderthals. The second one was largely about a deposit of Neanderthal fossils and tools found in a cave in El Sidrón, Spain. The remains were all deposited in a single layer in one flood event. They know this from several clues.

One of those clues was discovered when someone cataloging stone tools, waste flakes and the remains of a core stone realized some of them fit together. He was able to reassemble most of the original stone, from forty-nine thousand years ago.

The tools were at most very slightly used, which helped with the fitting.