Pachycephalosauridae

Part of speech: noun

Definitions

1. A family of extinct herbivorous dinosaurs characterized by thick, dome-shaped skulls used for head-butting behavior ; members lived mainly in the Late Cretaceous period and are known for bipedal locomotion and small to medium size
2. A group of prehistoric plant-eating dinosaurs noted for their thickened cranial domes; they were primarily bipedal and inhabited the Earth during the Late Cretaceous epoch
3. Dinosaurs belonging to a lineage distinguished by their dense, rounded skull roofs adapted for combat; these creatures were predominantly two-legged herbivores from the Late Cretaceous era

Etymology: Pachycephalosauridae is a family name created by paleontologists, not a word that grew naturally through speech. It is built from three Greek elements: "pachys" meaning "thick", "kephalē" meaning "head", and "sauros" meaning "lizard", with the Latin-style family ending "-idae" added to mark it as a taxonomic family. The name describes the group's most famous feature, a dome of thickened bone on top of the skull, which some species had covered in knobs and spikes. The naming follows the usual scientific convention for animal families. Zoologists formed these names from classical roots so that they would mean the same thing in any language, and the family name was formalised in the scientific literature in the nineteenth century, when the first members of the group were described from fossil material. The stem "pachycephalosaur" is the form used for the group's member genera, and the family name is simply that stem with the standard ending.

Synonyms: thick-headed dinosaurs