Denali National Park and Preserve, which in the past has given up fossils of prehistoric creatures, has done it again, this time relinquishing the fossilized tracks of two previously unknown species of birds.

Dr. Tony Fiorillo, a paleontologist and curator to the Museum of Nature & Science in Dallas, recently reported the discoveries that arose during a series of digs he led in Denali from 2006 to 2010. Details of the discoveries, which point to fossilized bird tracks dating back 70 million years, were outlined in a press release from the Dallas Museum of Nature and Science.

“My team had been working a 50-mile transect through the heart of the park and we found abundant bird tracks,” the paleontologist said in the release. “When the first tracks were found, we were a little speechless because they were so well-preserved.”

The scientist returned to Dallas and began researching the ancient birds that populated Alaska 70 million years ago. Denali had remarkable bird diversity during that time, and Dr. Fiorillo was determined to identify and verify every specimen encountered.

“Comparison of the tracks we found to those described in the literature by others showed us that many of the tracks we found were named for other places in either North America or Asia,” he says. “But two types of tracks were a little different. One track type was very large, and though it is similar to the fossil bird tracks found from older rocks here in the Dallas-Fort Worth Metroplex – Magnoavipes lowei – there were enough differences to give these Denali tracks a new name.”

According to Dr. Fiorillo, the larger set of bird tracks were so big that he and his team decided to name the species Magnoavipes denaliensis. The term reflects the vast area of discovery, utilizing the native Koyukon Athabascan name for the region and paying homage both to Denali National Park and nearby Mount McKinley, the tallest mountain in North America, according to a release from the Dallas Museum of Nature and Science.

The second, smaller bird’s name, Gruipeda vegrandiunis, indicates a separation from previously-discovered similar forms of the bird group Gruipeda, the release noted. Vegrandiunis is a combination of the Latin wordsvegrandis and unus, which translates to “tiny one.”

The discovery was announced, fully outlined, and supported in an academic paper, Bird tracks from the Upper Cretaceous Cantwell Formation of Denali National Park, Alaska, USA: a new perspective on ancient northern polar vertebrate biodiversity.

“This paper says two things,” says Dr. Fiorillo. “First – some 70 million years ago Denali National park had remarkable bird biodiversity. Rocks there record the richest record of avian biodiversity from a single rock unit anywhere in the world. And second – the fact that some of the forms of bird tracks we found in Alaska are also found elsewhere in the U.S. and Asia suggests that birds used Alaska as a seasonal nesting ground some 70 million years ago… just like modern birds use Alaska today.”

Dr. Fiorillo and his team of scientists plan to return to Denali this coming summer to continue their work.

You can read about some of the paleontologist's earlier discoveries in Denali at this site.