Varricchio provides detail to us about the answer. There’s evidence to suggest that unlike their modern-day cousins, some species of dinosaurs had quite a deal of parental instincts.
Several dinosaur species stayed with their eggs for the entire period of incubation, though it seems these species are usually those whose eggs took less time to hatch and were smaller in size.
Today's reptiles, on the other hand, tend to have an incubation period that lands between one and two months, which on average places them a lot closer to dinosaurs.
However, there are more details that lead researchers to believe dinosaurs aren't as closely related to reptiles than previously thought. In fact, the very way that modern reptiles interact with their developing eggs is different from how researchers believe dinosaurs acted.
Today's reptiles take the tactic of burying their eggs underground – it protects them from predators, and helps preserve warmth. Some reptiles will also hang around their clutch to add additional protection.
However, most reptiles abandon their eggs, and leave them to develop, hatch, and live without interacting with them again. With the long incubation periods of dinosaurs now clearer, the question arose of whether dinosaurs hung around for the lengthy incubation period, or left them alone.
Dinosaur parents that hung around would have provided additional protection from hungry predators. But for the eggs who took up to a year to hatch, like the Hypacrosaurus, it would have been quite the burden for dino moms and dads to remain in the same location.
If a predator knows you're always going to be in the same location for a long amount of time, even tiny dino brains might have figured out there are some tasty eggs nearby. Researchers have wondered if long incubation periods helped contribute to the extinction of some species.
The discoveries that Erickson and his team have made have called a number of previous theories into question.
One of the theories is the idea of a migration: Researchers have long suspected that a variety of dinosaur species spent the warm summer months in what are now areas of the arctic, and moved south for the winter to escape the cold, into areas of Canada. But with this incubation information, a migration seems more unlikely.