Monday, June 25, 2007

Giant Penguins in Peru

Fossil remains of two extinct species of penguin have been discovered on the Peruvian coast. The larger of the two, Icadyptes salasi, was about five feet tall and lived about 36 million years ago. The smaller, Perudyptes devriesi, was about three feet tall and lived about 42 million years ago.

Unlike living penguin species, the ancient, oversized birds had long, narrow beaks, with Perudyptes having an exceptionally long and spear-like beak, which Clarke said likely helped the animal gulp down large prey and attain its towering stature.

Perudyptes had features indicating a transition from wing to paddle. For instance, the giant penguin’s wing muscles were reduced compared with flight-able birds, “which basically are part of the changes to get to a paddle-like structure--you reduce these intrinsic wing muscles,” Clarke said.

To find out how the penguins landed in low-latitude regions, the scientists examined the geographic distribution and evolutionary relationships of other extinct penguins.

The results suggest the two Peruvian species result from separate dispersals, with the ancestors of Perudyptes dwelling in Antarctica before their equator-bound trek and Icadyptes originating near New Zealand.
One of the interesting findings is that penguins were in equatorial regions much earlier than expected.
“We tend to think of penguins as being cold-adapted species,” said lead study author Julia Clarke, a paleontologist at North Carolina State University and the North Carolina Museum of Natural Sciences. “But the new fossils date back to one of the warmest periods in the last 65 million years of Earth’s history. The evidence indicates that penguins reached low-latitude regions more than 30 million years prior to our previous estimates.”
The two new, extinct species, the giant penguin Icadyptes salasi (right) and Perudyptes devriesi (left) are shown to scale with the only extant penguin inhabiting Peru, Spheniscus humbolti (center). Credit: Kristin Lamm, via LiveScience