New research has confirmed that the wound in a 13,800-year-old mastodon skeleton was inflicted by humans. The mastodon skeleton was found in the 1970s with a sharp sliver of bone embedded in one of its rib bones. It was unclear at that time whether the bone sliver was a weapon point fabricated by humans, or if it was a broken piece of the mastodon’s own bone, or perhaps a chip from another animal embedded during a fight.

Michael Waters, an anthropologist at the Center for the Study of the First Americans at Texas A&M University, used modern radiocarbon-dating to confirm that the mastodon was indeed 13,800 years old and thus died 800 years before the Clovis people of North America were thought to have begun hunting on the continent. Then Waters used advanced CT technology to examine the bone point and hit the mother lode.

“We’re all familiar with hospital CT scanners where they can scan your body and look inside to see organs and bones,” Waters said. “This is a high-resolution industrial version that creates digital X-rays spaced every 0.06 millimeters [0.002 inches], about half the thickness of a piece of paper.”

This ultra-sharp look inside the rib revealed the needle-sharp shaft of the projectile point lodged inside the mastodon’s bone. The images suggested the point had been whittled down and sharpened, Waters said, the work of human hands.

To top it off, the researchers extracted bone protein and DNA from the projectile point itself, determining that the weapon had been made from the bones of yet another mastodon.

“That was even more exciting, because what that meant is whoever these hunters were that tracked down and killed the Manis Mastodon were hunting with weapons made from a previous kill,” Waters said.

A weapon as big around as a pencil, no less, which is damn impressive considering the size of the prey. Mind you, it appears this particular mastodon was in the twilight of its life anyway. Its teeth were worn down to nubbins, indicating advanced age. The bone point, either thrown like darts or launched with a small spear-thrower, was driven into the back of the creature, so the poor thing might have already been down when it the point pierced its rib.

This isn’t the first evidence of a pre-Clovis hunter-gatherer culture in the Americas 14,000 years or so ago. There’s even evidence of mastodons and mammoths being butchered and eaten during this period. The bone projectile, however, is the earliest hunting weapon found on the continent.

Here’s video of the CT scan: