Baby dinosaur fossils found in northern Alaska suggest that the reptiles lived year-round in the Arctic and were likely warm-blooded, a new study revealed.
The “unexpected discovery” of embryos and just-hatched babies from at least seven non-bird dinosaur species shows that the prehistoric animals survived extended periods of winter darkness and freezing temperatures in the inhospitable climates, according to research published Thursday in Current Biology.
“These findings, coupled with prolonged incubation periods, small neonate sizes, and short reproductive windows suggest most, if not all, PCF [Alaska’s Prince Creek Formation} dinosaurs were nonmigratory year-round Arctic residents,” the study’s authors wrote.
Previously, there was scant evidence that the beasts had the capacity to reproduce in polar climates, especially larger dinosaurs who were believed to have used the Arctic to migrate between modern-day Asia and North America, researchers said.
The new findings suggest the dinos stayed in the Arctic year-round, because small babies wouldn’t have been able to make “a long trek before the onset of a long, dark, cold winter,” study author Patrick Druckenmiller, professor of geology and director of the University of Alaska Museum of the North, told CNN.
Researchers found an array of small bones and teeth after excavating the remote area and inspecting hundreds of thousands of grains of sediment under a microscope over the last three decades, according to the study.
“Dinosaur eggshell is nice, but you can’t often tell very precisely who laid the eggs,” Druckenmiller told the outlet, adding that bones and teeth can be used to identify the genus or species of an animal.
The findings support the theory that dinosaurs were warm-blooded animals that could regulate their own internal heat, researchers said.
The new evidence suggests that small dinos might have hibernated during the brutal Artic winter, while large plant eaters might have survived by eating low-quality forage, scientists said.
“The value of this study is that it broadens our understanding to now include many kinds of dinosaurs living year-round in the Cretaceous Arctic,” Anthony Fiorillo, senior fellow at the Institute for the Study of Earth and Man at Southern Methodist University in Dallas, told CNN.
Researchers continue to learn about the travel habits and domestic tendencies of dinosaurs. In March, a study was published that concluded that hadrosaurs journeyed only about 50 miles from home.
In April 2019, a study found that duck-billed dinosaurs roamed the Arctic 69 million years ago.
All dinosaurs except some birds were believed to be wiped out 65 million years ago by an asteroid that hit Earth in what is now Mexico’s Yucatan Peninsula.