Plesiosaurus macrocephalus, juvenile Found by Mary Anning Argentinosaurus an amphibian

an amphibian

and became smaller farther away from the jaw tips

it was one of the three genera originally used to define Dinosauria

but was not seriously excavated for scientific study until the 1970's

characteristic of herbivores

Plesiosaurus macrocephalus, juvenile Found by Mary Anning Argentinosaurus an amphibianThis 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