Teenaged Mutant Dome-Headed Dinosaurs

Now this is why young folks get into paleontology. Two researchers at the University of Alberta have shown, via computer simulations, that adolescent pachycephalosaurs could lower their heads and butt each other at full speed, without knocking each other out cold (and prompting nearby adults to yell at them to settle down). Paleontologists had always suspected that these thick-skulled dinosaurs (sporting up to a foot of solid bone on their noggins) head-butted for the right to mate, but proof was lacking.

Lest you get any ideas, the researchers caution that pachycephalosaurs were well-suited to head-on impacts, since their backbones could buckle slightly (like accordions) and bounce back into shape. After all, there's no point winning the right to mate if you can't pick yourself up off the ground afterward!