Extinct animals are those species which are no longer living. This group includes prehistoric animals like dinosaurs and ice-age mammals, as well as moden species like the Dodo.
Troodon was described in 1856 by Joseph Leidy on the basis of a single small tooth. It was one of the first North American dinosaurs described. Learn more about the Troodon and other Late Cretaceous dinosaurs. More »
It isn't hard to imagine the world full of dinosaurs, even though these extinct animals haven't walked the earth for millions of years. Learn all about dinosaurs, including early dinosaur discoveries, dinosaur fossils, and dinosaur extinction.
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.