The genus Pygoscelis ('rump-legged') contains three living species of penguins collectively known as 'brush-tailed penguins'. Mitochondrial and nuclear DNA evidence suggests the genus split from other penguins around 38 million years ago, about 2 million years after the ancestors of the genus Aptenodytes. In turn, the Adelie penguins split off from the other members of the genus around 19 million years ago.