Species;"Vertebral formula"
"Aptenodytes forsteri";"C13 + CT2 + T6 + S13 + Ca7 + P1(5) = 42"
"Eudyptes chrysocome";"C13 + CT2 + T6 + S13 + Ca7 + P1(5) = 42"
"Pygoscelis adeliae";"C13 + CT2 + T6 + S14 + Ca6 + P1(5) = 42"
"Pygoscelis antarcticus";"C13 + CT2 + T6 + S14 + Ca6 + P1(5) = 42"
"Pygoscelis papua";"C13 + CT2 + T6 + S14 + Ca6 + P1(5) = 42"
"Spheniscus magellanicus";"C13 + CT2 + T6 + S13 + Ca6 + P1(5) = 41"