Every Type of Extinct Animals Explained in 17 Minutes

Every Type of Extinct Animal Explained 1. Andrewsarchus Before the age of lions and tigers and bears — before any of the large predators we recognize today even existed — there was something else walking the earth. Something bigger, stranger, and more unsettling than most people have ever heard of. Andrewsarchus was the largest land predator mammal that has ever lived. Not one of the largest. The largest. A creature that looked roughly like a wolf, if a wolf had been scaled up to the size of a small car, with a skull alone that measured nearly a meter in length. The jaws were lined with blunt, powerful teeth designed not just to bite but to crush — bone, shell, anything — suggesting a predator that didn't leave much behind when it was done. Here is the thing that makes Andrewsarchus genuinely strange beyond its size. We have almost no idea what it actually looked like. The entire scientific reconstruction of this animal — everything you've ever seen illustrated or described — is based on a single skull fragment discovered in Mongolia in 1923 by an expedition led by Roy Chapman Andrews, the explorer whose career is believed to have partly inspired Indiana Jones. One skull. No body. No limbs. No spine. Scientists looked at the skull, compared it to related species, and built the rest from inference and educated guesswork. The illustrations of Andrewsarchus — that massive, wolf-like, terrifying animal — are a best estimate. A scientific guess made from one piece of bone found in a desert a century ago. What we do know is that it lived roughly 45 million years ago during the Eocene epoch, roaming the forests and floodplains of what is now central Asia. Its closest living relatives, based on skeletal and genetic analysis, are not dogs or big cats. They are hippos and whales. The largest land predator mammal ever to exist is most closely related to the two most unexpected animals you could imagine. The skull of a monster. The family tree of a hippo. One piece of bone, a hundred years old, and we're still figuring out what we're looking at.