A new study has been published by researchers from Florida State University that challenges the notion that ancient dinosaurs were cold-blooded creatures that required tropical temperatures to survive. Paleontologists from Florida State University and the University of Alaska Fairbanks published a new study finding that nearly all types of dinosaurs, ranging from small and bird-like creatures to the massive Tyrannosaurus, not only reproduced in the Arctic but lived there year-round.
Researcher Pat Druckenmiller, the lead author of the paper and director of the University of Alaska Museum of the North, says that researchers have clear evidence dinosaurs were nesting in the Arctic. This study marks the first time anyone has demonstrated that dinosaurs were able to reproduce such high latitudes. The findings in the new study counter past hypotheses that dinosaurs migrated to lower latitudes during the winter.
The researchers say the findings provide some compelling evidence that the prehistoric creatures were warm-blooded. Druckenmiller and other researchers have been conducting fieldwork in the Prince Creek Formation in northern Alaska for over a decade. In that formation, they have unearthed the diversity of dinosaur species noting that most of them are new to science. Their latest discovery provided evidence that dinosaurs lived close to the ancient Arctic Ocean in the earliest stages of their life.
Researchers found tiny teeth, some less than two millimeters in length, and bones of seven species of perinatal dinosaurs. The term perinatal describes baby dinosaurs that are either embryonic or have just hatched. Study co-author Gregory Erickson says one of the biggest mysteries about Arctic dinosaurs was whether they seasonally migrated up north or lived there year-round. Erickson says the team unexpectedly found remains of perinatal representing almost every kind of dinosaur in the formation, calling it a type of prehistoric maternity ward.
Scientists will next attempt to identify and compare the fossils to similar specimens from creatures that lived at lower latitudes such as Alberta and in Montana. The team says past research shows the incubation period for the types of dinosaurs found range between three and six months depending on the species. Arctic summers are short, so if the dinosaurs laid their eggs as soon as it warmed in the spring, the offspring would be too young to migrate in the fall. That suggests they lived in the region year-round.