Add Yahoo as a preferred source to see more of our stories on Google. Here are the wildest extinct prehistoric creatures that aren't dinosaurs. It's hard to imagine how some of these animals even ...

An illustration of Procoptodon goliah, a giant kangaroo that weighed up to about 550 pounds and went extinct around 40,000 years ago Nobu Tamura via Wikimedia Commons under CC-BY-3.0 For many people, ...