Pygoscelis

The genus Pygoscelis ("rump-legged") contains three living species of penguins collectively known as "brush-tailed penguins".^[2]

Brush-tailed penguins Temporal range: Eocene to present
Pygoscelis antarctica
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Sphenisciformes
Family:	Spheniscidae
Genus:	Pygoscelis Wagler, 1832
Type species
Aptenodytes antarctica[1]
Species
Pygoscelis adeliae Pygoscelis antarctica Pygoscelis papua †Pygoscelis tyreei (fossil) †Pygoscelis calderensis (fossil) †Pygoscelis grandis (fossil)

Taxonomy

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.^[3]

Extant species

Genus Pygoscelis – Wagler, 1832 – three species

Common name	Scientific name and subspecies	Range	Size and ecology	IUCN status and estimated population
Adélie penguin	Pygoscelis adeliae (Hombron & Jacquinot, 1841)	Antarctica, Bouvet Island	Size: Habitat: Diet:	LC
Chinstrap penguin	Pygoscelis antarcticus (Forster, 1781)	Antarctica, Argentina, Bouvet Island, Chile, the Falkland Islands, the French Southern Territories, and South Georgia and the South Sandwich Islands	Size: Habitat: Diet:	LC
Gentoo penguin	Pygoscelis papua (Forster, 1781) Four subspecies P. p. taeniata (Peale, 1849) P. p. papua (Forster, 1781) P. p. ellsworthi Murphy, 1947 P. p. poncetii Tyler, Bonfitto, Clucas, Reddy & Younger, 2020	Falkland Islands, South Georgia and the South Sandwich Islands, and Kerguelen Islands	Size: Habitat: Diet:	LC

A 2020 study found that the gentoo penguin may actually comprise a species complex of 4 similar but genetically distinct species: the northern gentoo penguin (P. papua), the southern gentoo penguin (P. ellsworthi), the eastern gentoo penguin (P. taeniata), and the newly-described South Georgia gentoo penguin (P. poncetii).^[4][5] However, in 2021 the International Ornithological Congress recognized these as being subspecies of P. papua.^[6]

A study has estimated that there are about 3.79 million pairs of Adélie, 387,000 pairs of gentoo, and 8 million pairs of chinstrap penguins in their particular areas,^[7] making up 90% of Antarctic avian biomass.^[8]

Fossil species

• Pygoscelis grandis (Bahía Inglesa Formation, Late Miocene/Early Pliocene of Bahía Inglesa, Chile)
• Pygoscelis calderensis (Bahía Inglesa Formation, Late Miocene of Bahía Inglesa, Chile)
• Pygoscelis tyreei (Pliocene of New Zealand)

The latter two are tentatively assigned to this genus.