How animals are classified

There are well over a million named kinds of animal. To keep track of them, scientists sort them into groups within groups, like folders inside folders on a computer. This sorting is called classification, or taxonomy.

The seven main levels

From the biggest group to the smallest: kingdom, phylum, class, order, family, genus, species. A sentence to remember the order: "King Philip Came Over For Good Soup."

An example: the tiger

Scientific names

Every species has a two-part scientific name: the genus, then the species. The tiger is Panthera tigris and the lion is Panthera leo, which shows at once that they are close relatives. The genus starts with a capital letter, the species word does not, and the whole name is written in italics. The system was set out by the Swedish scientist Carl Linnaeus in the 1700s.

Why names help

Common names cause confusion. "Panther" can mean a leopard in India and a jaguar or puma in the Americas. A koala is often called a bear but is not one. A scientific name means one animal only, in every country and language.

What is a species?

A species is a group of animals that can breed with one another in nature and have young that can breed in turn. Lions and tigers are different species: they do not breed together in the wild.

Classification changes

The system reflects how closely animals are related. As scientists study DNA, they find that some animals are closer or more distant than once thought, and names and groups are revised. That is why two books can place the same animal a little differently. This site follows the GBIF Backbone Taxonomy.

See the classification of any animal on its page, or start with the six groups of animals.