An unexpected place. Dinosaurs didn’t just vacation in the high Arctic; they could have lived there all year. This is the conclusion of a new work published in the journal Current Biology whose new fossil evidence of hundreds of bones and teeth found along the Colville River in northern Alaska attests to this. The fossils, or rather microfossils, belonged to baby dinosaurs, the researchers say, suggesting that many species lived and thrived in some of the coldest parts of the planet.
The remains, which fell from outcrops of the Prince Creek Formation , represent up to seven families of dinosaurs, including tyrannosaurs, duck-billed hadrosaurs and horned and frilled ceratopsids.
“These are the northernmost [non-avian] dinosaurs that we know of,” says paleontologist Patrick Druckenmiller of the University of Alaska Museum of the North in Fairbanks. “And now it’s clear that they weren’t just migrating to polar latitudes. They are actually nesting, laying and incubating eggs … pretty much at the North Pole .”
Compelling proof that they were hot blooded
The fossils date back to the early late Cretaceous Maastrichtian age, some 70 million years ago, and their find adds to the evidence that dinosaurs were warm-blooded, thus dispelling the idea that Arctic species had migrated to higher latitudes. low and warm to lay eggs.
“We now have unequivocal evidence that they were nesting there as well. This is the first time that someone has shown that dinosaurs can reproduce at these high latitudes, “the scientists explain.
The researchers found tiny teeth and bones of perinatal dinosaurs, those that had just been born or were about to do so. Dinosaur babies came from seven species, from tiny bird-like creatures to fearsome tyrannosaurs, and they represent almost all types of arctic dinosaurs.
“One of the biggest mysteries about arctic dinosaurs was whether they migrated northward seasonally or were year-round dwellers,” says co-author Gregory Erickson. “We unexpectedly found perinatal remains that represent almost all types of dinosaurs in the formation. It was like a prehistoric maternity ward . “
The Arctic had an annual average of 6ºC when dinosaurs lived
According to the examination of the fossils, some of these dinosaurs incubated their eggs here for up to six months. That would have left little time for Arctic-nesting dinosaurs to migrate south before winter sets in. And any descendant would have had a hard time making the long journey, the authors comment.
Even though the prehistoric Arctic was slightly warmer than it is today, the dinosaurs that wintered there had to endure months of darkness, food shortages, cold temperatures – dropping below zero – and even snowfall. How would they have fought the cold? Hibernating? New questions arise after this recent discovery.
Referencia: Patrick S. Druckenmiller, Gregory M. Erickson, Donald Brinkman, Caleb M. Brown, Jaelyn J. Eberle. Nesting at extreme polar latitudes by non-avian dinosaurs. Current Biology, 2021; DOI: 10.1016/j.cub.2021.05.041
