Have you ever watched Ice Age (or either of its sequels) and wondered, “What the hell kind of animal is that, anyway?” I certainly have. Sometimes I wish there had been a prehistoric animals course available at my high school or even in college; it would have been so much fun to learn more about these animals that we’ll never be able to see live.

Just last year I learned about the giant sloths that roamed across North America and was absolutely entranced. What amazing, enormous creatures! I don’t know why I was so shocked; a lot of creatures were pretty big back then, right? Still, when you see an animal that you’ve simply never even thought of existing before, it just creates this sense of wonder that you think you’ve lost since childhood. I think that must be how my four-year-old feels when we look through our Wildlife Explorer sets and she first sights, say, a bush baby, or an impala.

Recently searching for more of these cool mammals of the past, I stumbled upon some pretty amazing creatures, such as:

Tasmanian Wolf: It wasn’t even really a wolf at all, but a marsupial with a pouch! It didn’t become extinct until the early 1920s or 30s, when farmers and bounty hunters sadly killed many of them in exchange for money from the government. Loss of habitat and the introduction of other wild dogs also contributed to the species’ extinction. Since it was so recent in our history, we have actual photos of the striped animals, as well as stuffed specimens, available for study.

Caspian Tiger: Isn’t this animal gorgeous? It has sadly been extinct since the 1950s. Like the Tasmanian Wolf, people claim to have seen it since; however no accounts have been able to be proven.

Irish Elk: As with sloths, I never would have imagined a deer to be this big. Also known as the Giant Deer, it has been extinct for nearly 8,000 years. It was nearly seven feet tall and its antlers spanned out up to twelve feet in length!

Cave Bear: Though not any bigger than modern bears, cave bears of Europe have been extinct for over 27,000 years. A fun fact about them—their skeletons were thought to be those of unicorns, dragons, and other creatures when they were first discovered!

I’d love to hear about any extinct (or alive, for that matter) mammals that you might stumble across. What’s the weirdest mammal you’ve ever heard of?