Plesiosaurus macrocephalus, juvenile Found by Mary Anning marine reptile Ornithischians Sagittal keel (visible midline ridge)

Sagittal keel (visible midline ridge)

A cast of the complete skeleton is also available

Pachycephalosaurs are today grouped with the horned ceratopsians in the group Marginocephalia

Location Hyampom

David Michael Letterman (born April 12

Plesiosaurus macrocephalus, juvenile Found by Mary Anning marine reptile Ornithischians Sagittal keel (visible midline ridge)This juvenile Plesiosaur is from the Jurassic of Lyme Regis, England. It was found by Mary Anning. Plesiosaurs (meaning "near lizard") were flippered marine reptiles from the Mesozoic Era they were not dinosaurs. Plesiosaurs are divided into two groups: the Plesiosauroids with long, snake like necks, tiny heads, and wide bodies, and the Pliosauroids, which had large heads with very strong jaws and short necks. The first plesiosaur skeletons were found