Niobrarasaurus Niobrarasaurus

Niobrarasaurus (meaning “Niobrara lizard”) is an extinct genus of nodosaurid ankylosaurian dinosaur which lived during the Late Cretaceous, around 87 to 82 million years ago. Its fossils were found in the Smoky Hill Chalk Member of the Niobrara Formation, in western Kansas, which would have been near the middle of the Western Interior Seaway during the Late Cretaceous. It was probably closely related to Nodosaurus.

The type species, Niobrarasaurus coleii, was discovered and collected in 1930 by geologist Virgil Cole. It was originally described by Mehl in 1936 and named as a species of Hierosaurus. It was then re-described as a new genus by Carpenter et al. in 1995. In 2002 the type specimen was transferred to the Sternberg Museum of Natural History, Hays, Kansas. It has been estimated at 5 m in length and around 227–453 in body mass according to Thomas Holtz.