New penguin remains from the Pliocene of Northern Chile

Abstract

Until recently, all described fossil penguin species from South America were recovered from the Atlantic coast. The description of three fossil species of Spheniscus from Peru and Chile now allows a clearer estimate of the historical diversity on the Pacific coast. Here we describe a further new species from a Pliocene level of the Bahía Inglesa Formation, northern Chile. This taxon, the first to be described from this sequence, is based on a partial skeleton lacking a skull. These remains are clearly referable to the living genus Pygoscelis, and share a mosaic of characters with extant species of the genus. Pygoscelis grandis sp. nov. was around the size of a King Penguin, and therefore much larger than any extant Pygoscelis species. Our cladistic analysis places P. grandis within the Pygoscelis clade as the sister taxon of living representatives. Living species of Pygoscelis have a sub-Antarctic distribution, and the presence of this species slightly south of the Tropics during the Pliocene may relate to end Neogene global cooling.