Tyrannosaurus starts his day with a rumbling broadcast, not dissimilar from the thunderstorm that has just passed. One of the hatchlings decides to join the chorus.
Two male Pachycephalosaurus dispute their right to breed with a herd of females, as those and the youngsters look on.
Here I've gone with the controversial view that Dracorex and Stigymoloch are juvenile forms. I'm 50/50 on that theory.