Ancient humans used mastodon bones to hunt the giant beasts

A 13,900 year old projectile point is likely the oldest evidence of mastadon hunts in the Americas.
A scan of a mastodon skeleton with an arrow pointing to the trajectory of the spear.
A mastodon with an arrow pointing to the trajectory of the spear. Center for the Study of the First Americans, Texas A&M University

As early as 23 million years ago, giant mastodons roamed the Earth. These elephant ancestors were typically shorter than their modern day descendants, but were more dense and also bore signature tusks. These gigantic mammals were also hunted by the earliest humans before going extinct about 13,000 to 12,700 years ago.

A team of researchers have now found what’s believed to be the oldest direct evidence of mastodon hunting in the Americas. They studied bone fragments embedded in a mastodon rib unearthed in the 1970s at Washington States’ Manis site and found the tip of a weapon inside. The weapon is a projectile that was actually made from the bone of another mastodon. 

[Related: From the archives: 100 years of mastodon fossil fascination.]

The findings were described in a study published on February 2 in the journal Science Advances.

“We isolated the bone fragments, printed them out and assembled them,” said co-author Michael Waters, an anthropologist and director of Texas A&M’s Center for the Study of First Americans, in a statement. “This clearly showed this was the tip of a bone projectile point. This is the oldest bone projectile point in the Americas and represents the oldest direct evidence of mastodon hunting in the Americas.”

The Manis projectile is about 13,900 years old and predates other projectiles found at the site by about 900 years. These tools are associated with the Clovis people, whose spear points have been found in several fossil sites across the country.

The Manis site mastodon rib with embedded point to the left. CREDIT: Center for the Study of the First Americans, Texas A&M University.

“What is important about Manis is that it’s the first and only bone tool that dates older than Clovis. At the other pre-Clovis site, only stone tools are found,” Waters said. “This shows that the First Americans made and used bone weapons and likely other types of bone tools.”

According to the study, the projectile got stuck within the mastodon’s rib. However, the bone used to make the point on the projectile came from another mastodon’s leg bone. It was also shaped into a point on purpose.

“The spear with the bone point was thrown at the mastodon. It penetrated the hide and tissue and eventually came into contact with the rib. The objective of the hunter was to get between the ribs and impair lung function, but the hunter missed and hit the rib,” said Waters.

A study published in 2011 on this same rib bone used radiocarbon dating to determine the age of the sample,  and a later genetic study confirmed that it belonged to a mastodon. This new study used CT images and 3D software to create 3D images of each bone fragment. The team was able to fit the pieces back together like a puzzle to show what the projectile looked like before it entered the mastodon’s rib and splintered. 

[Related: These footprints could push back human history in the Americas.]

The Manis site gives scientists more insight into the lives of the first people to live in the Americas, but the debate about when people arrived is still ongoing. Waters believes that the first people likely came to the Americas by boat along the North Pacific before moving south.

“There appears to be a cluster of early sites in the Northwestern part of the United States that date from 16,000 to 14,000 years ago that predate Clovis. These sites likely represent the first people and their descendants that entered the Americas at the end of the last Ice Age,” said Waters.

Some of the estimates of when humans first inhabited North America typically ignore indigenous knowledge that life and culture in North America exists far beyond even the 23,000 year estimate.

“There are many sites that have really good dating and really good reports that are much older,” Paulette Steeves, a Cree-Metis archaeologist at Algoma University who studies Indigenous history, and author of The Indigenous Paleolithic of the Western Hemisphere, told PopSci in 2021. Steeves has compiled hundreds of finds that she says presents credible evidence that humans in the Americas date back before 16,000 years.

A set of fossilized footprints found in New Mexico’s White Sand National Park are one of the most discussed examples that contradict the 14,000 to 16,000 year settlement hypothesis, but they are not the only evidence. Researchers have also found possibly 30,000-year-old stone tools in a cave in central Mexico and non-native animal bones that may bare evidence of being cooked by humans were found in another spot in Mexico are between 28,000 and 30,000 years old.