Baby dinosaurs floated around in the cool area that is now the Alaskan Arctic about 70 million years ago, according to the “unexpected” discovery of more than 100 babies dinosaur bones and teeth there, a new study reports.
It was surprising to find evidence of a prehistoric nursery in such a cold place, the researchers said. Even in the heat Chalk period (145 to 66 million years ago) Alaska had an average monthly temperature of about 43 degrees Fahrenheit (6 degrees Celsius), and for about four months of the year, dinosaurs would have lived in permanent darkness and handled snowfall, they said.
The Prince Creek Formation in northern Alaska, where the fossils were found, is “the longest north that dinosaurs have ever lived,”
After analyzing the baby’s teeth and bones, the research team determined that the remains belonged to seven different dinosaur species. The discovery indicates that dinosaurs may have lived in this cool region all year, as the babies would have been too small for annual migrations shortly after hatching, Erickson said. If these little dinosaurs and their parents stayed in Alaska all year round, they were probably warm-blooded or endothermic – a feature that would have allowed them to stay active even when the temperature dropped, he added.
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Scientists have known that dinosaurs lived in polar regions since oil workers found dinosaurs in the 1950s, Erickson said. In the following decades, researchers with the University of Alaska Museum of the North discovered the remains of teenage baby dinosaurs in the state.
“Our job is like panning for gold, finding small bones in a sea of sediment,” says lead researcher Patrick Druckenmiller, professor of geoscience and director of the University of Alaska Museum of the North. Bachelor and graduate students have contributed thousands of hours of work to the project, which uncovered baby dinosaurs belonging to several herbivorous species of duck dinosaurs, ceratopsians (horned dinosaurs), thescelosaurids (small, bipedal ornithopods) and pachycephalosaurosaurs (dinosaur phalosaurosaurs). . They also found baby remains from carnivores, including tyrannosaurids, deinonychosaurs (maniraptoran dinosaurs), and ornithomimosaurians (ostrich-like dinosaurs).
“The most recent surprise was the smallest ceratopsid tooth that I am aware of in North America or anywhere,” Druckenmiller told WordsSideKick.com in an email.
The winter months in the Alaskan Arctic at the time were likely to be the harshest, especially for herbivores whose food would either be covered in snow or dead, Erickson said.
“How they pulled it off, we do not know,” Erickson said. Some small dinosaurs may have dug themselves to sleep, but larger dinosaurs – such as duck dinosaurs and tyrannosaurs – were unable to dig. “Maybe they just had to stick it out as one moose or musk ox. Somehow they got through, ”Erickson said.
Remains set and stays warm
Based on knowledge about the life cycle of dinosaurs, the researchers concluded that these baby dinosaurs remained seated after hatching, as they would not have had time to mature before winter entered. This is partly because dinosaur eggs took a long time to incubate – anywhere from three to six months, Erickson and colleagues determined in a 2017 study published in the journal Proceedings of the National Academy of Sciences.
These long egg hatching times, “combined with the fact that you had a very short growing season up there to bloom before winter entered, [baby dinosaurs] just did not have time “to grow big enough before migrating south, Erickson said.” There is no way these tiny dinosaurs made the march down to Alberta to escape the winter. “
There is proof that some long-necked sauropod dinosaurs and and-billed dinosaurs at lower latitudes in western North America migrated, but it is likely that the Alaskan dinosaurs, especially the smaller individuals, were set, the researchers said. Spending the winter in polar conditions would be challenging for cold-blooded or ectothermic creatures. In fact, paleontologists have not found ectothermic animal fossils – like those from crocodiles, lizard or snakes – at the Prince Creek Formation, Druckenmiller said. Furthermore, there is only one ectotherm known from the Alaskan Arctic today: tree seeds, which essentially turns into an ice pop in the winter.
Based on this as well as endothermic results from other analyzes of studies the rapid growth rates of dinosaurs, it is “likely that dinosaurs had some degree of endothermia to cope with the winter conditions, especially the low / no light and cold temperatures,” Druckenmiller wrote in the email.
The study was published online Thursday (June 24) in the journal Current biology.
Originally published on WordsSideKick.com.