Scientists have discovered a 70-million-year-old nest filled with the remains of baby protoceratops dinosaurs, providing clues about the dinosaurs' early behavior.

“I, for one, cannot think of another dinosaur specimen that preserves 15 juveniles at its nest in this way,” says lead author Dr. David Fastovsky, from the University of Rhode Island's Department of Geosciences.

While large numbers of eggs have been associated with other dinosaurs, such as the carnivorous oviraptor or certain duck-billed hadrosaurs, finding multiple juveniles in the same dino nest is quite rare. Fastovsky and his colleagues analyzed the dinosaur remains along the next, which measured about 70 centimeters in diameter and was round and bowl-shaped. All were found at Djadochta Formation, Tugrikinshire, where it is believed sand “rapidly overwhelmed and entombed” the youngsters while they were still alive.

The researches conclude that the 15 dinosaurs all showed juvenile characteristics. These include short snouts, proportionately large eyes, and an absence of adult characteristics, such as the prominent horns and large frills associated with adults of this species. At least 10 of the 15 fossil sets are complete.

The nest and its contents imply that protoceratops juveniles remained and grew in their nest during at least the early stages of postnatal development. It further implies that parental care was provided The large number of offspring, however, also suggests that juvenile dinosaur mortality was high, not only from predation, but also from a potentially stressful environment.