Giant North American “hell pigs” may have munched on bones around 30 million years ago, while their smaller counterparts ripped through softer material, like flesh, new research finds.

The “hell pigs,” scientifically known asArchaeotherium(“ancient beast” in Greek), were a group of pig-like creatures that could be as tall as humans while standing on four legs and potentially weigh than 2,000 pounds (1,000 kilograms).

Researchers have known aboutArchaeotheriumsince 1850. But now, a new tooth analysis reveals that these beasts’ feeding strategies were varied than previously assumed. By examining tooth wear, researchers saw that larger species were crushing bones or other hard material, while smaller species were likely shearing soft foods, potentially giving them different roles on the ancient North American landscape.

“We can’t assume that they were doing the same thing,”Brynn Wootena doctoral candidate at Vanderbilt University in Tennessee, told Live Science.

Wooten presented preliminary findings from her research Thursday (Nov. 13) at the Society of Vertebrate Paleontology 2025 annual meeting. The findings haven’t been peer-reviewed yet, as Wooten and her colleagues still have to complete their research and submit it to a journal.

Whale of a pig

Archaeotheriumroamed across North America from about 37 million to 23 million years ago. Despite their vaguely hoggish appearance,Archaeotheriumwas closely related to whales and hippos than to pigs. Their heads were around 30% of their total body length (it varied by species), but their small brains meant they weren’t the brightest tools in the Paleogenic shed.

“Archaeotheriumhas a brain-to-body mass ratio similar to that of reptiles, so they were very unintelligent creatures,” Wooten said. “Their heads were massive, but they had little tiny brain cases.”

Researchers previously suggested thatArchaeotheriumcould have been active predators, scavengers and/or vegetation strippers. Bite marks on the fossils ofPoor brotherhood— small camel relatives that used to roam North America — indicate thatArchaeotheriummay have huntedPoor brotherhoodand stored some of the carcasses for leftovers.

For the new research, Wooten andLarisa DeSantisan associate professor of biological sciences at Vanderbilt University, examined a variety ofArchaeotheriumteeth from different states, including Nebraska, South Dakota, Oregon and Colorado. By using dental microwear texture analysis, which involves creating 3D scans of the tooth surface with a powerful microscope, they could compare wear variation between the differentArchaeotheriumteeth.

On the whole,Archaeotheriumwas typically similar to peccaries (pig-like animals found in the Americas), which shear their food. However, wear on the larger-bodiedArchaeotheriumwas statistically indistinguishable from that of lions and hyenas and indicative of an animal that crushed its food.

“It’s really interesting that the large ones are capable of crunching bones,” DeSantis told Live Science. “The small ones are not.”

The crushing wear could mean that the larger species engaged in scavenging behaviors, potentially using their great size to bully other predators off their kills, the researchers suggested. On the other hand, the largerArchaeotheriumcould have been consuming hard vegetarian foods, such as tubers or woody browse. The soft veggie option for smallerArchaeotheriummay have been leaves and grasses.

So far, the dental analysis reveals only the texture ofArchaeotheriumfood — not which species they ate. Wooten will now explore other research techniques, includingcalcium isotope analysisto confirm whether bone was part ofArchaeotherium‘s diet.