February 1, 2011

Denali Find: Two New Fossilized Prehistoric Bird Tracks

According to findings released by an expert in Arctic paleontology, fossilized tracks from two newly discovered prehistoric birds have been found in Alaska's Denali National Park.

Tony Fiorillo, a paleontologist and curator at the Museum of Nature and Science in Dallas, told Reuters that the previously unknown birds were among a wide variety of birds that left fossilized tracks in Denali.

"The skies over Denali were a pretty busy place," he said.

The birds are considered a new species and have been given names by Fiorillo and his team.

He published his findings in the current issue of the Journal of Systematic Paleontology.  He said that previous research determined that pterosaurs also dwelled during the Cretaceous period in Denali.

Denali National Park, one of the most popular visitor destinations in Alaska, is drawing increased attention from paleontologists.

Fiorillo said that because of the characteristics of the rock formations there, Denali has proven to be one of the best places in the world to find prehistoric bird tracks.

Thousands of prehistoric bird tracks have been found in Denali.

"It's the most biodiversity represented by the tracks (in the world)," he told Reuters.

Some of the tracks matched species that dwelled during that time period in more southern latitudes of North American or in Asia.

"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, who lead the research, told Reuters.

Fiorillo has conducted paleontological digs in search of prehistoric bird tracks in Denali since 2006 and has examined other fossils in the park since before then.

He helped discover the first dinosaur track in the park in 2005, which happened to be in a location close to the park road that summer tourist travel.

According to his research, hadrosaurs were plentiful in Alaska during the Cretaceous period as well.

The researchers calculate that Alaska held about 500,000 hadrosaurs during that period, which is roughly equivalent to modern caribou populations in Alaska.

Fiorillo said that the climate at the time in the now-frigid region was fairly mild, "somewhere between annual temperatures of Calgary and that of Portland, Oregon." 

He said that the land was well vegetated, with forests as well as open areas.

The researcher speculates that the methane produced from the hadrosaurs, each of which emitted about 10 times as much of the gas as a modern cow, combined to create a small greenhouse effect and incrementally warm the region.

Fiorillo and colleagues from the University of Texas and the University of Alaska Fairbanks believe the hadrosaurs helped maintain the open spaces in the vegetation. 

The findings were presented at an American Geophysical Union conference held last month in San Francisco.


On the Net: