Protoceratops was a very common, small, herbivorous dinosaur first discovered in Mongolia.
It had a parrot-like beak, and a bony frill over its neck that was probably used for display to other Protoceratops, much like the crests of chameleon lizards today.
There appear to be two forms of the frill, suggesting there were differences between males and females.
Recently a Protoceratops nest was found containing hatchlings, leading some scientists to believe this successful species cared for its young.
References: text is from the park placard with minor edits.