What is "protoceratopsid"

n. (context zoology English) Any member of the Protoceratopsidae.

Protoceratopsidae is a family within the group Ceratopsia. The name Protoceratopsidae is derived from Greek for "first horned face". Protoceratopsids have so far been found in the Late Cretaceous, dating to between about 99.6 and 70.6 million years ago. Although Ceratopsians have been found all over the world, protoceratopsids are only known from Asia with most specimens found in China and the Nemegt Basin in Mongolia. As Ceratopsians, protoceratopsids were herbivorous, with constantly replacing tooth batteries made for slicing through plants and a hooked beak for grabbing them. Protoceratopsids were relatively small, between 1-2.5 m in length from head to tail. Their bony frill and horns were much smaller than more derived members of Ceratopsia. Protoceratopsids were likely slow runners and tended to move at a walk or a trot. Their legs may have been straight, creating an upright posture, but there are some theories that they were splayed out to the side, contributing to their slowness. There is evidence that Protoceratops formed groups. Specimens of juveniles and young adults are often found in groups, although adults tend to be solitary. The nature of these groups is not completely known, though herds of young likely formed for protection from predators, and adults are believed to have come together for communal nesting.