The new species are the first fossils to indicate a significant and diverse presence of penguins in equatorial areas during a period that predates one of the most important climatic shifts in Earths history, the transition from extremely warm temperatures in the Paleocene and Eocene Epochs to the development of icehouse Earth conditions and permanent polar icecaps. Not only did penguins reach low latitudes during this warmer interval, but they thrived: more species are known from the new Peruvian localities than inhabit those regions today.
By comparing the pattern of evolutionary relationships with the geographic distribution of other fossil penguins, Clarke and colleagues estimate that the two Peruvian species are the product of two separate dispersal events. The ancestors of Perudyptes appear to have inhabited Antarctica, while those of Icadyptes may have originated near New Zealand.
The new penguin specimens are among the most complete yet discovered that show us what early penguins looked like. Both new species had long narrow pointed beaks now believed to be an ancestral beak shape for all penguins. Perudyptes devriesi has a slightly longer beak than seen in some living penguins but the giant Icadyptes salasi exhibits a grossly elongated beak with features not known in any extinct or living species. This species beak is sharply pointed, almost spear-like in appearance, and its neck is robustly built with strong muscle attachment sites. Icadyptes salasi is among the largest species of penguin yet described.
Although these fossils seem to contradict some of what we think we know about the relationship between penguins and climate, Clarke cautions against assuming that ju
Contact: Tracey Peake
North Carolina State University