The Arkansaurus Dinosaur is Officially Official
The Arkansas legislature resolved last year that Arkansaurus Fridayi was the state's official dinosaur and that was good. But now the Journal of Vertebrate Paleontology has announced the newly recognized creature and that is really official.
Arkansaurus (meaning "Arkansas lizard") is a genus of ornithomimid theropod dinosaur. Arkasaurus fridayi, the type and only species, was declared the official Arkansas state dinosaur in 2017. The dinosaur was discovered in Lockesburg, Arkansas, and was a bipedal ornithomimosaur dinosaur. Its nearest relative is the ornithomimosaur Nedcolbertia. It is named for the state of Arkansas and its discoverer J.B. Friday, who found the dinosaur's fossilized foot on his farm in 1972. It is the only dinosaur fossil currently described from Arkansas. The fossil was officially described in 2018 by paleontologists ReBecca Hunt-Foster and James Quinn in the Journal of Vertebrate Paleontology.
Arkansaurus was probably a fast moving omnivore between 6 and 15 feet (1.8 and 4.6 m) tall. Its long arms would likely have ended in three fingered grasping hands.
A single autapomorphy, unique derived trait, was indicated: the strong curvature of the foot claws. These are normally rather flat with ornithomimosaurians.
Ornithomimisaur tracks of similar age are known from north of Moab, Utah, at the Mill Canyon Dinosaur Tracksite, in the Ruby Ranch Member of the Cedar Mountain Formation (Early Cretaceous). This tracksite also preserves the tracks of ankylosaur, hadrosaur, sauropod and several size classes of theropod dinosaurs, along with crocodiles and birds. A similar fauna has been noted from the Trinity Group in Arkansas.
Arkansaurus fridayi lived during the Albian and Aptian stages of the Early Cretaceous.