The fossil dinosaurs huddle together in the ancient nest.
Scientists once believed that dinosaurs generally followed a crocodile-like model of child care—they would lay their eggs and leave their nests for good. This idea was replaced by the view that dinosaurs raised their young for a time after hatching, the way many birds do.
(Related: "Mother Pterosaurs Laid Soft Eggs, New Fossil Hints.")
Now, Fastovsky explained, people understand that the ancient reptiles had parenting styles unlike those of any animals alive today.
Fifteen babies, as seen in the newfound fossil nest, is an unusually large number of offspring for any animal to nurture at once, Fastovsky said. Modern animals tend to have a few young, in which they invest heavily, like humans, or they have a "zillion babies" and show no parental care, like mosquitoes.
"So these [dinosaurs] seem to be something else."