Researchers working with specimens at the University of Alaska Museum of the North have described a new species of hadrosaur, a type of duck-billed dinosaur that once roamed the North Slope of Alaska in herds, living in darkness for months at a time and probably experiencing snow. Ugrunaaluk (oo-GREW-na-luck) kuukpikensis (KOOK-pik-en-sis) grew up to 30 feet long and was a superb chewer with hundreds of individual teeth well-suited for eating coarse vegetation. Earth sciences curator Pat Druckenmiller said the majority of the bones used in the study came from the Liscomb Bone Bed, a fossil-rich layer along the Colville River in the Prince Creek Formation, a unit of rock deposited on the Arctic flood plain about 69 million years ago.

"Today we find these animals in polar latitudes," Druckenmiller said. "Amazingly, they lived even farther north during the Cretaceous Period. These were the northern-most dinosaurs to have lived during the Age of Dinosaurs. They were truly polar."

The name, which means ancient grazer, was a collaborative effort between scientists and Iñupiaq speakers. Druckenmiller worked with Ronald Brower Sr., an instructor at the University of Alaska Fairbanks Alaska Native Language Center, to develop a culturally and geographically appropriate name that honors the native Iñupiaq people who live there today.

Druckenmiller; UAF graduate student Hirotsugu Mori, who completed his doctoral work on the species; and Florida State University's Gregory Erickson, a researcher who specializes in the use of bone and tooth histology to interpret the paleobiology of dinosaurs, published their findings in Acta Palaeontologica Polonica, an international quarterly journal that publishes papers from all areas of paleontology.

Druckenmiller and Erickson have previously published documentation suggesting that during this time period, a distinct, polar fauna existed in what is now northern Alaska. At the time, Arctic Alaska was covered in a polar forest because the climate was much warmer. Since it was so far north, the dinosaurs had to contend with months of winter darkness and snow. "The finding of dinosaurs this far north challenges everything we thought about a dinosaur's physiology," Erickson said. "It creates this natural question. How did they survive up here?"