Neosaurus is a little-known pelycosaur

Pelycosaur

The pelycosaurs are an informal grouping composed of basal or primitive Late Paleozoic synapsid amniotes. Some species were quite large and could grow up to 3 meters or more, although most species were much smaller...

 of the family Sphenacodontidae

Sphenacodontidae

Sphenacodontidae is a family of small to large, advanced, carnivorous, Late Pennsylvanian to middle Permian pelycosaurs. Primitive forms were generally small in size , but during the later part of the early Permian these animals grew progressively larger , to become the top predators of their...

. It was related to the well known Dimetrodon

Dimetrodon

Dimetrodon was a predatory synapsid genus that flourished during the Permian period, living between 280–265 million years ago ....

, although much smaller (about 1 m in length) and lived during the Early Permian

Permian

The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...

. Its fossils were found in the Jura region of France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

.

A species of the hadrosaur dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

 Hypsibema

Hypsibema

Hypsibema is a little-known genus of dinosaur from the Late Cretaceous . Its giant fossils were found in the U.S. states of North Carolina and Missouri...

, H. missouriensis

Hypsibema missouriensis

Hypsibema missouriensis is a species of plant-eating dinosaur in the genus Hypsibema, and the state dinosaur of the U.S. state Missouri. One of the few official state dinosaurs, bones of the species were discovered in 1942, at what later became known as the Chronister Dinosaur Site near Glen Allen,...

, is also called Neosaurus, although because the name was already in use, that species was renamed Parrosaurus before being reassigned to Hypsibema.