Researchers have found hundreds of baby dinosaur bones in the Alaskan Arctic, suggesting that dinosaurs may have lived at cold northern latitudes year-round.

Transcript

AUDIE CORNISH, HOST:

In the 1950s, scientists began to unearth dinosaurs in the far northern and southern reaches of the planet. But those finds raised a question - did dinosaurs live in the Arctic and Antarctic year round or simply wander their seasonally in search of plants or other dinosaurs to eat?

AILSA CHANG, HOST:

A study out today in the journal Current Biology advances that debate. It suggests that dinos lived all year in what is now northern Alaska, enduring freezing winters, snow and months of darkness.

GREGORY ERICKSON: Basically, these - you know, these animals were living at the - at an extreme we didn't think that they could live that.

CORNISH: Gregory Erickson of Florida State University was on the research team. A key piece of evidence behind his team's claim is a new collection of bones and teeth from tiny baby dinos from more than 70 million years ago.

ERICKSON: I mean, frankly, we were stunned when we found all these different types of dinosaurs. It - you know, it (laughter) - it was like it was a prehistoric maternity ward up there.

CHANG: Up there is northern Alaska, near the Arctic Coast. The team traveled four days by car, plane and boat to get there. Even then, some of the excavation sites were only accessible by rappelling off a cliff.

CORNISH: After scraping through the sediment with dental tools, they found the remains of a baby tyrannosaurus, duckbilled dinos, triceratops relatives and more.

CHANG: And given the long incubation times of dinosaur eggs - three to six months for some species they identified - the scientists say these dinosaurs must have been year-round residents.

MICHAEL D'EMIC: And so there really wasn't enough time to both lay the eggs, incubate, hatch and then make that seasonal migration.

CORNISH: Michael D'Emic of Adelphi University wasn't involved in the work, but he does study dinos. In fact, we caught him...

D'EMIC: In Wyoming, digging up dinosaurs.

CORNISH: What impressed him was not just the find itself, but how tedious the work was.

D'EMIC: They found over a hundred bones and teeth that could fit on the head of a pin. And then they laboriously picked through it under the microscope for hundreds of hours, if not thousands.

CHANG: He says the work also supports the theory that some dinosaurs could regulate their blood temperature, like we can.

D'EMIC: I wouldn't go so far as to say all, but I would say it's safe to say that the majority of dinosaur groups were more warm-blooded than cold.

CHANG: Some of these dinosaurs may have also hibernated underground. Here's Erickson again.

ERICKSON: I can't imagine any of these small animals enduring the cold if they didn't dig burrows and that sort of thing. But what about the giant ones? What about the giant tyrannosaur we have up there? What were they doing?

CORNISH: Now, this study may not answer that question, but Erickson says it does prove you can learn a lot about the biggest animals ever to walk the planet by looking under a microscope.

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