Doggy style

Doggy style is a sex position. This name refers to the initial position assumed by dogs when mating (see canine copulation). It is also known as kitty style, retrocopulation, or simply rear entry, or by its Latin name, coitus more ferarum ("sex like beasts do it").

This position has been used since antiquity. It is described in the Kama Sutra as "the congress of a cow" and is listed in The Perfumed Garden.

In this position, the receiving partner crouches on all fours with the legs slightly spread, while the penetrating partner penetrates the receiver vaginally or anally from behind with their penis or strap-on dildo.

In biology, mating is the pairing of opposite-sex or hermaphroditic internal fertilization animals for copulation and, in social animals, also to raise their offspring. Mating methods include random mating, disassortative mating, assortative mating, or a mating pool.

Anyways here are some pictures of different types of species mating doggy style.

My Question is

WHY DO WE CALL IT DOGGY STYLE????????