Notes on some fossil penguins, including a new Genus from Patagonia

Two incomplete but well-characterized penguin bones, dissociated tarsometatarsus and humerus, from the marine Patagonia formation in the vicinity of Trelew and Gaiman in the valley of the Chubut River, Chubut, Argentina represent a uniquely distinctive, hitherto unknown fossil penguin of approximate late Oligocene age. This is the smallest known penguin, living or fossil. The tarsometatarsus is unusually slender and is further unique among known penguins in having no intermetatarsal foramen. It is named Microdutes tonnii, new genus and species, with the tarsometatarsus as holotype. Some remarks are also made about a collection of fossil penguin bones in the Museo de La Plata from the Isla Vicecomodoro Marambio (=Seymour Island).