Duck-billed dinosaurs roamed the Arctic in herds

Young and old hadrosaurs lived together, track site in Alaska suggests

HERD MENTALITY Duck-billed dinosaurs lived together in multigenerational herds in the Arctic, thousands of new tracks in Alaska suggest.

KAREN CARR ILLUSTRATION

Duck-billed dinosaurs were the wildebeests of the ancient Arctic.

Around 70 million years ago, during the Late Cretaceous, the plant-eating reptiles probably lived in multigenerational herds — just like modern grazers, a dinosaur track site in Alaska suggests.

The tracks, a jumbled bunch of large and small footprints, are the first solid sign that duck-billed dinos, or hadrosaurs, settled together year-round in the polar region, which at the time probably had a climate similar to the modern Pacific Northwest’s. The animals “weren’t just accidental tourists in this area,” says Anthony Fiorillo. “They were thriving.”

DINO TRACKS Duck-billed dinosaurs lived together in multigenerational herds in the Arctic, thousands of new tracks in Alaska suggest Courtesy of Perot Museum of Nature and Science

People stereotype dinosaurs as swamp creatures, says Fiorillo, a paleontologist at the Perot Museum of Nature and Science in Dallas. But, he says, dinosaurs were actually a highly adaptable bunch that lived in a variety of habitats — even the Arctic.

In 2007, Fiorillo and colleagues discovered thousands of tracks clustered in a soccer field–sized patch of mountain in Denali National Park and Preserve. Measurements of the tracks, three-lobed footprints that dapple the rock like a layer of sunken leaves, suggest that duck-billed dinosaurs ranging from youngsters to adults shared a similar stomping ground, the team reports June 30 in Geology

Like the African plains roamed by young and old herd animals today, Alaska might have been the “Serengeti of the Cretaceous,” Fiorillo says. 

Meghan Rosen is a staff writer who reports on the life sciences for Science News. She earned a Ph.D. in biochemistry and molecular biology with an emphasis in biotechnology from the University of California, Davis, and later graduated from the science communication program at UC Santa Cruz.