What is Marginocephalia?

Triceratops horridus, Pachycephalosaurus wyomingensis, their most recent common ancestor and all descendents. Marginocephalia is a major branch of ornithischian dinosaurs, uniting two very different-looking groups—pachycephalosaurs and ceratopsians—based on a shared, name-prompting bony shelf or "margin" at the back of their skulls, which began modestly in early Jurassic members but expanded into dramatic frills and domes in later forms. Marginocephalians experimented with a wide range of head shapes and display structures, from thickened skull roofs to broad, ornamented frills. Their jaws and beaks were adapted for cropping and slicing vegetation, and in many Late Cretaceous environments they lived alongside ornithopods, often filling complementary feeding roles. Marginocephalia showcases how a single anatomical innovation can blossom into extraordinary diversity.

Click here to search Dinochecker for marginocephalians. Marginocephalia is derived from the Latin "margin" (fringe, border) and the Greek "kephale (head) and "-ia" (neuter plural), referring to the frills of its members, formed by bones at the back of their skulls.