A phylogeny of extant penguins (18 forms) was estimated on the basis of 70 integumentary and breeding characters. Integumentary characters included structure and color of bill and legs, and plumage of adult, immature, and downy chick. Breeding characters included eggs, nesting, and sociability of immatures. Gavia was placed at the root, and 11 species of representative procellariiform groups completed the outgroup.