Ancient footprints have revealed that large, bone-crushing dogs stalked the ashy wastes of North America in the wake of a devastating Yellowstone supereruption 12 million years ago.
Researchers uncovered the footprints above the skeletons of extinct rhinoceroses called Teleoceras in the Ashfall Fossil Beds of northeastern Nebraska. The dog tracks mark the first direct evidence of large carnivores in the beds, which are nicknamed "Rhino Pompeii" because they have preserved so many Teleoceras rhinos that perished in widespread fallout from volcanic activity at Yellowstone.
