Ancient hunters used spears like pikes to make mammoths 'kill themselves,' study finds

Popular depictions of prehistoric hunts tend to show ancient humans hurling their spears into mammoths and mastodons.

But such a technique would have been less than useless — leaving a hunter with no spear and an angry mammoth, a new study argues.

Instead, Ice Age hunters may have used a sophisticated hunting tool to kill prey like mammoths — or predators like saber-toothed cats — using the animals’ own power and weight, according to findings published Wednesday in PLOS ONE.

Thirteen thousand years ago, “people were living among saber tooths and giant bears that are twice the size of grizzlies, mastodons and bison,” Scott Byram, a stone tool specialist at the University of California, Berkeley and co-author of the study, told The Hill

To survive in those circumstances, Byram and his co-authors hypothesized, prehistoric hunters “probably needed a weapon that could actually be used a little bit more defensively than just as an offensive throwing spear.”

Why? Because in addition to the risks involved in throwing away one’s weapon in the face of a charging mammoth, the components that went into those spears could be both brittle and expensive. Proper trees to make spear shafts might be found only every few hundred miles, making them particularly valuable. 

The larger question the study considered concerns the blades Byram’s team hypothesized to have been on those spears. Prehistoric hunters, Byram said, would have had to face a serious shortcoming in their most deadly weapon.

“Stone tools can be very sharp, but they're often very brittle, right?” Byram said. Their razor-sharp edges “can go through softer tissue. It can go for a deep wound — if it doesn't strike anything really hard.” 

“But if it hits bone,” he added, “it's going to shatter.”

That design challenge is at the center of modern controversy over a famous type of fluted stone blade known as Clovis points. First discovered in the 1920s amid the ribs of mammoths in Clovis, N.M. and typically made of obsidian or jasper, the blades have since been found across North America — a region once dominated by enormous mammals.

Recent scholarship has seen fierce debate over the use of those blades, which gave their name to an entire culture of mammoth hunters.

A 2021 study in the Journal of Archeological Science found that, contrary to widespread belief they had been used as spear points, they likely were used as hand knives rather than to kill mammoths — a finding based on the lack of “breakage patterns” that would be characteristic of their being repeatedly jammed into big animals.

But in 2022, a competing study in the same journal countered that archeological evidence from mammoth bones showed evidence of deep penetration wounds of the sort that Clovis point-tipped spears might inflict. 

The new study from Byram and his co-authors helps bridge the two perspectives by hypothesizing that the Clovis-era spear was a far more sophisticated tool — and wielded in a very different way — than previously imagined.

Byram and his co-author Jun Sunseri built a rig that let them propel a replica Clovis spear into an oak plank under different levels of force — which allowed them to show that neither a thrown nor thrust spear could easily kill a mammoth.

While such a weapon might get through the creature’s protective hide, “it doesn’t do much more than that,” Byram said. “The impact just dies.”

That’s why modern spear-armed big game hunters instead rely on making the animal come to them — and, the study suggests, why their historic counterparts did the same. 

In Southern Africa, where Sunseri did his fieldwork, his mentors among the VhaVenḓa people taught him that the engineering of a spear’s base was just as critical as the construction of its blade.

By conducting research into the ethnographic record, Byram and Sunseri found copious evidence that human hunters — from Russians killing bears to southern Africans hunting lions — used their spears like pikes, with their butts firmly thrust into the ground as the hunters faced down an animal that impaled itself on the blade.

Byram theorized they would do this for the same reason premodern armies — whose infantry faced deadly attacks from enemies mounted on a more familiar megafauna, the horse — relied on corps of pikemen to fend off charging horses.

“You can actually stop the animal before you get killed,” Byram said. The momentum of the charging animal “keeps it moving so it gets stuck through the hide.”

But what about the brittleness problem? Byram and Sunseri suggested that might be addressed by an as-yet-unexplained feature of the Clovis point: the fact that it was sharpened not only on the front, but on the back as well.

That led them to propose an alternate use for an artifact found across Clovis-era campsites, a “foreshaft” made of wood or bone that scientists had long assumed the spear point was bound onto as a means of connecting to the longer wooden shaft.

In their PLOS paper, Byram and Sunseri proposed that this artifact was actually used for something else — which would help explain both why there are so many mammoth bones showing evidence of Clovis points, and so few Clovis points broken by impact with mammoth bones.

They hypothesized that the spear point was lashed to the shaft, with the sharpened foreshaft bound across it as a sort of splint.

As hunters approached a mammoth from the sides — its deadly tusks swinging — they would allow it to swing its weight onto the blade, the study theorized.

Then, as the impact of the mammoth forced the spear through its hide, the force would also perpetuate through the point to cut the bindings attaching the spearhead to the shaft and foreshaft — pushing the Clovis point back out of the way and snapping the weapon open like the back of a drywall anchor.

Byram described this as “a hollow point bullet effect” fueled by the animal’s own momentum, which would create a zone of expanding force that ripped through flesh and brought an animal down.

This is not how prehistoric hunting is generally imagined, Byram acknowledged. “People tend to glorify traditional hunting techniques a little bit,” he said. “They tend to talk about hunting spears as though [hunters] are using their own force to kill the animal — as opposed to getting the animal to kill itself.”

This bias, Byram suggested, may underestimate the amount of inner strength required to keep a spear level in the face of an enraged mammoth or charging cave bear. 

“There’s a lot of courage involved in this for sure,” he said.