Hippos are large, semi-aquatic mammals with a barrel-shaped body, short legs, and a large head. They have gray or brownish-gray skin, with pinkish areas around their eyes, mouth, and ears. Hippos are ...

Woolly mammoths are at the forefront of controversial de-extinction efforts, writes Rebecca Woods in a commentary.

His system of nomenclature and classification is fundamental to the study of not just evolution but of taxonomy and ...