Ancient bird fossils found in Alaska

Tue Feb 1, 2011



Fossils of two prehistoric birds were found in Denali National Park, Alaska A US scientist has identified two prehistoric birds after studying fossilized tracks recently discovered in Alaska's Denali National Park.

Arctic paleontology expert Tony Fiorillo said the birds were among a wide variety of birds that left fossilized tracks in Denali.

"The skies over Denali were a pretty busy place," said Fiorillo, also a curator at the Museum of Nature and Science in Dallas.

Fiorillo and his team named the birds 'Magnoavipes denaliensis,' and 'Gruipeda vegrandiunis,' Reuters reported.

The first species which left especially large tracks was named after the park and the second one that left small tracks was called 'Gruipeda vegrandiunis,' roughly translating to 'tiny one.'

According to the study published in the Journal of Systematic Paleontology, the Denali park is one of the best places on Erath to look for tracks of prehistoric birds due to its unique rock formations.

Previous studies had shown that pterosaurs -- flying winged reptiles -- also lived in the area during the Cretaceous period, Fiorillo said.

"It's the most biodiversity represented by the tracks (in the world)," he added referring to the high variety of bird tracks found in Denali.

Some of the tracks belong to species from more southern latitudes of North America or in Asia, which shows that birds migrated to Alaska to breed and nest in Cretaceous summers just as they do today.

"Isn't it kind of neat to think about the idea that in the Cretaceous, 70 million years ago, Alaska might have served the same kind of avian needs that it does today?" Fiorillo said.

Fiorillo has been conducting paleontological studies to find prehistoric bird tracks in Denali since 2006 and has been exploring other fossils in the park.

He also helped discover the first dinosaur track near the park road in 2005.

Fiorillo also found that lots of hadrosaurs -- duckbilled, plant-eating dinosaurs -- lived in Alaska during the Cretaceous period.

Fiorillo and colleagues from the University of Texas and the University of Alaska Fairbanks suggest that Alaska held about 500,000 hadrosaurs at any given time during that period which is about the same number of modern caribous in Alaska.

Alaska's climate at the time was fairly mild, "somewhere between annual temperatures of Calgary and that of Portland, Oregon," Fiorillo said adding that the now-frozen land was also well vegetated back then, with forests as well as open areas.

Scientists think the warm climate was caused by the methane produced from the hadrosaurs, each of which emitted about 10 times as much of the gas as a modern cow.

The methane emission, therefore, created a small greenhouse effect and warmed the region.

Fiorillo and his colleagues believe that hadrosaurs also helped maintain the open spaces in the vegetation.

TE/ZHD