Neosaurus

{{Short description|Extinct genus of synapsids}}

{{Automatic taxobox

| fossil_range = Late Carboniferous-Early Permian, {{fossilrange|300|295.5}}

| image = Neosaurus.jpg

| image_caption = Holotype

| taxon = Neosaurus

| authority = Nopsca, 1923

| type_species = {{extinct}}Neosaurus cynodus

| type_species_authority = (Gervais, 1869)

| synonyms =

• Geosaurus cynodus Gervais, 1869

}}

Neosaurus ('New Lizard') is an extinct genus of pelycosaur-grade synapsids from the Late Carboniferous-Early Permian of the Jura region of France. It is known only from a partial maxilla or upper jaw bone and an associated impression of the bone.Nopcsa, F. 1923. "Die Familien der Reptilien". Fortschritte der Geologie und Palaeontologie 2 : 1–210 The teardrop shape of the teeth in the jaw indicate that Neosaurus belongs to the family Sphenacodontidae, which includes the better-known Dimetrodon from the Southwestern United States. The maxilla was first attributed to an early diapsid reptile in 1857,Coquand, H. 1857. "Mémoire geologique sur l'existence du terrain permien et du représentant du grès vosgien dans le département de Saône-et-Loire et dans les montagnes de la Serre (Jura)". Bulletin de la Société geologique de France 14 : 13–47Coquand, H. 1858. "Mémoire geologique sur l'existence du terrain permien et du représentant du grès vosgien dans le département de Saône-et-Loire, ainsi que dans les montagnes de la Serre (Jura)". Mémoires de la Société d'Émulation du département du Doubs 2 : 1–40 and later a crocodylomorph in 1869,Gervais, P. 1869. Zoology and paléontologie générales. Nouvelles recherches sur les animaux vertébrés vivants ou fossils, Première série . 263 pp. Arthus Bertrand, Paris before finally being identified as a sphenacodont synapsid in 1899,Baur, G. and Case, EC 1899. "The history of the Pelycosauria, with a description of the genus Dimetrodon, Cope". Transactions of the American Philosophical Society, New Series 20 : 5–62 a classification that still holds today.{{Cite journal | last1 = Falconnet | first1 = J. | doi = 10.4202/app.2012.0105 | title = The sphenacodontid synapsid Neosaurus cynodus, and related material, from the Permo-Carboniferous of France | journal = Acta Palaeontologica Polonica | year = 2013 | url = http://hal.upmc.fr/hal-01255355/document | doi-access = free }}

A species of the hadrosaur dinosaur Hypsibema, H. missouriensis, is also called Neosaurus, although because the name was already in use, that species was renamed Parrosaurus before being reassigned to Hypsibema.{{cite journal|last1=Gilmore|first1=Charles Whitney|author-link1=Charles Whitney Gilmore|last2=Stewart|first2=Dan R.|title=A New Sauropod Dinosaur from the Upper Cretaceous of Missouri|jstor=1299165|journal=Journal of Paleontology|publisher=Society for Sedimentary Geology|volume=19|issue=1|pages=23–29|date=January 1945}}