How did early humans manage to kill massive numbers of mammoths in quick succession? According to new research, these early hunters got by with a little help from their new best friends, dogs.

In the journal Quaternary International, a new study titled, in part, “How do you kill 86 mammoths?” looked into the remains of massive hunting sites in Europe, where large numbers of mammoth remains were found. The sites, some of which had the remains of more than 100 individual mammoths, also held human shelters carefully constructed from mammoth bones.

Originally, scientists explained these sites by looking at modern elephant hunting and postulating that hunting—or even natural disasters—could have led to the large number of mammoths killed there. But the weapons available to hunters during this time period wouldn’t have been able bring down this many mammoths. Something else must have been going on.

Anthropologist Pat Shipman thinks that these early hunters might have had some help from early domesticated dogs. Shipman explained her hypothesis in a statement:

"Dogs help hunters find prey faster and more often, and dogs also can surround a large animal and hold it in place by growling and charging while hunters move in. Both of these effects would increase hunting success," Shipman said. "Furthermore, large dogs like those identified by Germonpré either can help carry the prey home or, by guarding the carcass from other carnivores, can make it possible for the hunters to camp at the kill sites." Shipman said that these predictions already have been confirmed by other analyses. In addition, she said, "if hunters working with dogs catch more prey, have a higher intake of protein and fat, and have a lower expenditure of energy, their reproductive rate is likely to rise."

The results seem to line up with a study released last fall, which showed that dogs were likely domesticated in Europe between 18,800 and 32,100 years ago by groups of hunter-gatherers.