Partial limb skeleton of a “giant penguin” Anthropornis from the Eocene of Antarctic Peninsula

Abstract

Abstract: The fossil record of the Antarctic penguins is dated to the late Paleocene of Sey− mour (Marambio) Island, but the largest sphenisciforms, generaAnthropornisandPalae−eudyptes, originate from the Eocene La Meseta Formation. Here, the most complete large−scale reconstruction of a limb skeleton (a whole wing and a partial hind leg) of a Paleogene Antarctic penguin is reported. All bones are attributable to a single individual identified asAnthropornissp. The comparative and functional analyses of the material indi− cate that this bird was most probably well−adapted to land and sea while having a number of intriguing features. The modern−grade carpometacarpal morphology is unique among known Eocene Antarctic species and all but one more northerly taxa.