The earliest people who lived in North America shared the landscape with huge animals, the so-called “megafauna”. On any given day these hunter-gatherers might encounter a giant, snarling saber-toothed cat ready to pounce. They could see a group of mammoths stripping tree branches. Maybe a herd of giant bison would stampede past.

All of these creatures went extinct about 13,000 years ago, likely due to a combination of climate change and over-hunting. Indeed, evidence from ancient North American sites shows American Clovis hunter-gatherers at least occasionally killed or scavenged ice age megafauna such as mammoths. At such sites, scientists found preserved bones of megafauna together with the stone tools used for killing and preparing these animals as food. 

Clovis spearpoints

Among these tools are the iconic Clovis spearpoints with their distinctive flutes — concave areas left behind by removed stone flakes that extend from the base to the middle of the point. The points were likely made this way so they could easily affix them to a spear shaft.

But how exactly did humans with stone-tipped spears bring down a six-ton beast like a mammoth? It’s a more complicated question than meets the eye — one that has puzzled scientists for years.

It might seem obvious that the hunter-gatherers simply surrounded a strangling mammoth at which point they would have thrown their spears at the animal. However, research carried out by experts at the University of California, Berkeley suggests this may have been an extremely impractical strategy. Humans simply do not have the shoulder force to throw a stone-tipped spear, no matter how sharp, with sufficient momentum to pierce through a mammoth’s thick hide.

Instead, a new study proposes a different method altogether — one that relies on the force of the hunted animals themselves.

Rather than throwing spears, the researchers suggest that early humans might have used a technique involving planted pikes. Humans wielding pikes tipped with these Clovis points, likely braced them against the ground and angled them upward. When a charging mammoth or saber-toothed cat hit the spear, the animal’s own momentum would drive the point deep into its body, inflicting a fatal wound.

Rethinking Clovis Points: A Grounded Approach

This method, the researchers argue, could explain the durable design of Clovis points. Made from chert, flint, or jasper, these tools featured fluted bases that might have been crucial to their function. When the point pierced flesh, it behaved similarly to a hollow-point bullet, causing extensive internal damage.

“This ancient Native American design was an amazing innovation in hunting strategies,” said Scott Byram, a research associate with Berkeley’s Archaeological Research Facility and the first author of the new study.

“This distinctive Indigenous technology is providing a window into hunting and survival techniques used for millennia throughout much of the world.”

The Berkeley team’s work included both a historical review of evidence such as cave paintings and experimental studies. They built replica Clovis points and tested them against simulated forces, revealing how the spears would have reacted to the weight and speed of a charging megafauna. The experimental system is based on prior experiments where researchers fired stone-tipped spears into clay and ballistics gel—something that might feel like a pinprick to a 9-ton mammoth.

“The kind of energy that you can generate with the human arm is nothing like the kind of energy generated by a charging animal. It’s an order of magnitude different,” said co-author Jun Sunseri, a Berkeley associate professor of anthropology. “These spears were engineered to do what they’re doing to protect the user.”

Ancient innovation

The researchers add that Clovis spears were probably more sophisticated than meets the eye. Only the stone points themselves can be recovered. However, beyond the stone tip, a Clovis spear also included bone, wood, pine pitch, and lacing that kept everything together. A good Clovis spear was difficult to make and resource-intensive. It would be extremely risky to throw such an expensive spear at a mammoth, knowing that it could be lost or broken in the process.

“It just started to make sense to me that it actually had a different purpose than some of the other tools,” Byram said. “Unlike some of the notched arrowheads, it was a more substantial weapon. And it was probably also used defensively.”

Their findings suggest that this grounded spear technique could have been a common hunting practice, allowing small human groups to successfully take down animals much larger than themselves.

In the coming months, the research team plans to further test their theory by constructing a more complex model to simulate what an actual encounter between a planted spear and a charging mammoth might have looked like. This ongoing research could potentially rewrite our understanding of how early humans interacted with their environment and hunted the largest animals of their time.

As we learn more about the past, we continue to discover just how innovative our ancestors were in their fight to endure the Ice Age.

The findings appeared in the journal PLOS ONE.