If the cheetahs had evolved in lockstep with the pronghorns, this then raised the question of what they were eating in Alaska. At the time, the land would have been filled with a range of other herbivores, including bison, horses, and caribou.
But the data gleaned from the bones show, extraordinarily, that that is not what they were eating.
“They’re not just eating mostly fish,” explains Cassatt-Johnstone. “It seems like they’re eating almost exclusively fish.”
“When we compare our data to published modern data of carnivores that we know eat exclusively aquatic marine resources, we see that they’re sitting in a position right between orcas, which are exclusively fish eaters, and outer island wolves from British Columbia, which are commonly known as sea wolves because they eat almost exclusively fish.”