The paper argued that the evidence was consistent with a human-made bone projectile point having been driven into the mastodon’s rib — pre-Clovis evidence of mastodon hunting on the Pacific Coast of North America.

The case was substantially stronger than anything that had been published about the Manis site before.

But it remained, in the view of some researchers, not yet conclusive.

The fragments had not been visualized as a weapon.

Their shape had not been fully characterized.

The question of whether they really came from a deliberate weapon or from some other source — a piece of bone carried in the mastodon’s gut that had been displaced post-mortem, for example, or some other unusual but natural process — had not been completely ruled out.

What was needed was a way to see the fragments themselves, not as they were distributed through the rib, but as they had been before they shattered: to reconstruct the object whose tip they had once formed.