The fossil record of penguins in South America comes from both Atlantic and Pacific coasts and is restricted to findings in Argentina, Chile, and Peru; their stratigraphic distribution ranges from the late Eocene?–early Oligocene (Acosta Hospi− taleche 2005) to the late Pliocene (Emslie and Correa 2003). Most of the described fossil species come from the early Mio− cene of Patagonia, Argentina (see Ameghino 1891, 1895, 1899, 1901, 1905, 1920; Moreno andMercerat 1891; Simpson 1972, 1975a). Recently, the South American fossil penguins have been taxonomically revised (e.g., Acosta Hospitaleche 2003, 2005; Acosta Hospitaleche and Canto 2005; Acosta Hospitaleche and Tambussi 2004a, b; Acosta Hospitaleche et al. 2005) and concluded in a reduction of 35 formerly named penguin species to about 14 different taxa,which are exclusive to South America (Acosta Hospitaleche and Tambussi 2004a, b). The following taxa are known fromArgentina: Arthrodytes andrewsi (Ameghino, 1901) and Paraptenodytes robustus (Ameghino, 1895) (both from the upper Eocene–lower Oligo− cene San Julian Formation, Patagonia), Eretiscus tonnii (Sim− pson, 1981), Palaeospheniscus bergi Moreno and Mercerat, 1891, Ps. patagonicus Moreno and Mercerat, 1891, Ps. bilo− culata Simpson, 1970 (all from the lower Miocene Gaiman Formation, Patagonia), Paraptenodytes antarcticus (Moreno and Mercerat, 1891) (from the lower Miocene Monte Léon Formation and the lower upper Miocene Puerto Madryn For− mation, both Patagonia) and Madrynornis mirandus Acosta Hospitaleche, Tambussi,Donato, and Cozzuol, 2007 (this vol− ume; from the lower upper Miocene Puerto Madryn Forma− tion, Patagonia). The Chilean fossil penguin taxa include: Paraptenodytes robustus, Pa. antarcticus, Palaeospheniscus sp., Pygoscelis grandis Walsh and Suárez, 2006, Py. cal− dernensis Acosta Hospitaleche, Chávez, and Fritis, 2006, Spheniscus sp. (all from the upper Miocene–lower Pliocene, Bahia Inglesa Formation), and Spheniscus chilensis Emslie and Correa, 2003 (late Pliocene, Mejillones Formation). The following taxa are known from Peru: a Spheniscidae indet. (late Eocene–early Oligocene, Otuma Formation), Palaeo− spheniscus sp. (lower middleMiocene, Chilcatay Formation), Spheniscus urbinai Stucchi, 2002 and S. megaramphus Stuc− chi, Urbina, and Giraldo, 2003 (both from the upper Mio− cene–lower Pliocene of the Pisco Formation).
Thus, findings of fossil representatives of the extant pen− guin genus Spheniscus are restricted to Peru and Chile and have been known from the late Miocene to late Pliocene hith− erto. For the Pisco Formation of Peru, Noriega and Tambussi (1989) and Cheneval (1993) already mentioned probable new taxa of Spheniscidae, but did not name them; recently they have been described by Stucchi (2002) and Stucchi et al. (2003) as Spheniscus urbinai from different sites of late Mio− cene to early Pliocene age and as S. megaramphus from the upper Miocene of the Montemar locality. In Chile, fossils of Spheniscus are described as cf. Spheniscus by Walsh and Hume (2001) from the middle Miocene–lower Pliocene Bahía Inglesa Formation and as S. chilensis Emslie and Cor− rea, 2003 from the late Pliocene (Mejillones Formation) of Cuenca del Tiburón, Península de Mejillones.
Herein a new fossil species of Spheniscus is described again from the Pisco Formation in Peru, but coming from older deposits at the Cerro la Bruja locality of latest mid− dle/earliest late Miocene (11–13 Ma) age.