Previously unknown penguin species lived in equatorial Peru millions of years ago

Two previously unknown penguin species lived in equatorial regions tens of millions of years earlier, when the earth was much warmer than it is now, a joint study by a team of US, Argentinean and Peruvian researchers has revealed.

Washington, June 26 : Two previously unknown penguin species lived in equatorial regions tens of millions of years earlier, when the earth was much warmer than it is now, a joint study by a team of US, Argentinean and Peruvian researchers has revealed.

Palaeontologist Dr. Julia Clarke, assistant professor of marine, earth and atmospheric sciences at North Carolina State University, together with colleagues, studied the two newly discovered extinct penguin species - discovered by Peruvian palaeontologists in 2005.

The first of the two new species, Icadyptes salasi, stood five feet tall and lived about 36 million years ago. The second species, Perudyptes devriesi, that lived some 42 million years ago, was approximately the same size as a King Penguin (2 1/2 to 3 feet tall).

The second species represented a very early part of penguin evolutionary history. However, both of these species lived on the southern coast of Peru, said Dr. Clarke.

According to her, these new penguin fossils - among the most complete to show what early penguins looked like - call into question the hypotheses about the timing and pattern of penguin evolution and expansion.

Previous theories have suggested that the penguins probably evolved in high latitudes (Antarctica and New Zealand) and then moved into lower latitudes that are closer to the equator, about 10 million years ago - long after significant global cooling that occurred about 34 million years ago.

"We tend to think of penguins as being cold-adapted species. Even the small penguins in equatorial regions today: 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," said Dr. Clarke.

Both species had long narrow pointed beaks - now believed to be an ancestral beak shape for all penguins.

Perudyptes devriesi had a slightly longer beak than seen in some living penguins but the giant Icadyptes salasi, among the largest species of penguin yet described, exhibited a grossly elongated beak with features not known in any extinct or living species.

This species' beak was sharply pointed, almost spear-like in appearance, and its neck was robustly built with strong muscle attachment sites.

"These Peruvian species are early branches off the penguin family tree, that are comparatively distant cousins of living penguins," said Dr. Clarke.

The study, "Paleogene equatorial penguins challenge the proposed relationship between penguin biogeography, diversity, and Cenozoic climate change" appears online in the June issue of the Proceedings of the National Academy of Science (PNAS).

ANI