1 - Tyrannosaurus Rex
Topping our countdown at No. 1, Tyrannosaurus Rex is an animal whose fossil remains are known to school children and adults from all parts of the world as the most fearsome predator that ever walked the planet. Standing about 40 feet in length, with a massive head and jaws that could have eaten an adult man in a single bite, one look at the remains of this brutish beast sends chills down the spine of anyone considering time travel to the Cretaceous Period.
So, if Tyrannosaurus Rex and the other dinosaurs were so ferocious, why did they die out? This is one of paleontology's great mysteries, but evidence from the fossil record suggests that there may have been a catastrophic event such as a meteor impact or volcanic eruption that killed off dinosaurs and most other living things on the planet at the time.
One thing is certain about dinosaurs in general and Tyrannosaurus Rex in particular: no other group of extinct animals has captivated humans quite so much. Perhaps it's not so much the animals themselves that command our attention but the idea that such a catastrophe could cause humans to suffer a similar fate. Then, millions of years later, a future life form might be sitting around a table wondering what wiped out such a seemingly well-established creature as Homo sapiens.