65 million-year-old cow relative looked like a chinchilla and weighed only a pound

An illustration of a furry four-legged creature pokes it head and front legs out of a pile of leaves. It it brown and white with whiskers.

Researchers in Colorado have discovered the fossilized skull of a tiny, now-extinct mammal that lived around 65 million years ago, in the aftermath of the dinosaur-killing asteroid strike.   

The newly identified species, Militocodon lydae, was around the size of a chinchilla and weighed up to 1 pound (455 grams), yet it was part of a group that likely gave rise to modern hoofed mammals, such as cows, deer and pigs.