Primer registro de cráneos asignados a Palaeospheniscus (Aves, Spheniscidae) procedentes de la Formación Bahía Inglesa (Mioceno Medio-tardío), Chile

Although the skulls of the Spheniscidae are unusual in the paleontologic record, they show important features useful in the systematics of the group, as well as in the rest of the birds. Until now, fossil occurrences were restricted to six skulls: Paraptenodytes antarctica and one new species from the Gaiman Formation (Early Miocene) and Puerto Madryn Formation (Late Miocene) of Argentina, respectively; Spheniscus megaramphus and S. urbinai from the Pisco Formation (Late Miocene), Peru; Marplesornis novaezealandiae from New Zealand (Pliocene); and Spheniscidae cf. Spheniscus from the Bahia Inglesa Formation (Middle-Late Miocene), Chile. Five new materials have been exhumed from this last unit. These skulls, which come from the Caldera locality (Region of Atacama, Chile), have been preliminarily assigned to Palaeospheniscus (Aves, Spheniscidae), constituting the first skulls described for this species. We made an important contribution to the knowledge of the fossil avifauna of Chile and particularly of the Bahia Inglesa Formation.