While Mammoths and Saber Toothed Tigers died out long ago, modern mammals are increasingly at risk of extinction due to human intervention. Explore some species that are no longer with us.
What's the difference between a mammoth and a mastodon?
Mammoths and mastodons have a few significant differences. Learn more about the difference between the prehistoric animals at HowStuffWorks. See more »
Why were so many prehistoric animals so big?
A lot of prehistoric animals were big, but why? Get the answer at HowStuffWorks. See more »
How Pterosaurs Worked
Pterosaurs were a group of flying reptiles that first appeared on Earth about 215 million years ago. Learn more about the giant pterosaurs. See more »
9 Extinct Exotic Sea Creatures
Extinct sea creatures were exotic as well as ferocious. See this list of 10 extinct sea creatures to learn about the beasts that lived in Earth's waters. See more »
10 Terrifying Extinct Cetaceans
Extinct cetaceans are more like sea monsters, and can make nightmares seem dull. See these 10 extinct cetaceans to explore the ancient world. See more »
The Ultimate Saber-Tooth Cat Quiz
The long-extinct saber-tooth cat was more than a prehistoric tiger. Take our quiz and discover how the saber-tooth cat was a mix of lion, tiger and bear. See more »
Loading more content
Here's What Happens When You Swallow a Leech
Why Don't More Babies Get Mom's Last Name?
No Link Between Immigrants and Crime
See More Headlines »