Most of South America's diverse avian fossil record is derived from terrest
rial deposits. A Late Miocene to Early Pliocene marine avian assemblage is
reported here from the Bahia Iglesa Formation of north-central Chile. Sulid
ae, Phalacrocoracidae, Pelagomithidae, Diomedeidae, and Spheniscidae report
ed here are the earliest occurrences in Chile. The presence of the Chilean
spheniscid penguin may prove significant in the taxonomy and radiation of t
he genus Spheniscus.