Before the Spanish introduced modern horses to the New World, horses roamed wild in North America, then they disappeared, but ...

This discovery is the first of its kind, with a perfectly preserved 3-month horse of a now-extinct species in the Siberian ...

“Scientists estimate that we’ve identified only one-tenth of all species on Earth,” said Dr. Shannon Bennett, chief of science at the California Academy of Sciences, in a statement.

Nearly one third of all known vertebrate species are either used or traded by humans around the world. “We’ve become this kind of super-predator,” says Rob Cooke at the UK Centre for Ecology ...

Some of the best known species on Earth may not be what they seem. Credit...Steve Holroyd/Alamy Supported by By Carl Zimmer Naturalists have been trying for centuries to catalog all of the species ...