DALLAS – After years of searching the Arctic, scientists have discovered the fragment of a baby dinosaur’s tiny jawbone, providing what they believe is a significant clue to the behavior of certain dinosaurs.

The theory: Some meat-eating dinosaurs, called dromaeosaurs, lived year-round in the Arctic.

Decades ago, scientists realized that birds might share a common ancestor with dromaeosaurs. So they thought that some dinosaurs migrated south with the changing seasons in search of food like modern-day birds.

Today, most researchers assume that polar dromaeosaurs made the Arctic their home year-round, because their relatively small sizes would make migration difficult.

Dr. Anthony Fiorillo and his team at Southern Methodist University published their findings in PLOS One. The presence of this baby dinosaur also suggests that during the Cretaceous Period, the Arctic was rich in prey to support families of these meat-eating dinosaurs.

There would have been enough food available in the harsh Arctic environment to sustain a population of carnivorous dinosaurs, said Fiorillo.

“To me, this specimen suggests that dromaeosaurs were thriving in an environment because their prey, the herbivorous dinosaurs, had also successfully adapted to an extreme environment,” he said.

More information on the lives of different polar dinosaurs can help scientists better understand how they adapted to live year-round in these colder, darker regions.

The discovery of this juvenile jawbone could also help in understanding the diversity of animals that lived in the ancient Arctic, said Dr. Patrick Druckenmiller, a paleontologist at the University of Alaska Museum of the North.