Dakotadon

Dakotadon (meaning "Dakota tooth") is a genus of iguanodont dinosaur from the Early Cretaceous (Valanginian to Barremian) Lakota Formation of South Dakota, USA, known from a partial skull. It was first described in 1989 as Iguanodon lakotaensis, by David B. Weishampel and Philip R. Bjork. Its assignment has been controversial. Some researchers suggested that "I." lakotaensis was more basal than I. bernissartensis, and related to Theiophytalia, but David Norman has suggested that it was a synonym of I. bernissartensis. Gregory S. Paul, working on a revision of iguanodont species, gave "I." lakotaensis its own genus, Dakotadon, in 2008. He measured its length at and body mass at .

==History and naming== thumb|left|Type locality of Dakotadon within the Lakota Formation In November 1985, a partial and associated skeleton was brought to the attention of South Dakota School of Mines and Technology professor emeritus John Willard. The material had been found earlier by Louis Rossow, who collected geological specimens from outcrops on homesteads in Whitewood, South Dakota, who assembled a crew of his family to carve the specimen from the outcrop. It was then stored in his garage until his son Dale Rossow informed Willard of it. Willard then brought the snout of the skull to Morton Green of the SDSMT Museum of Geology, who turned it over to museum paleontologist Philip R. Bjork to investigate. The specimen was donated to the museum, being accessioned as SDSM 8656. Coming from a hogback north of Sturgis, South Dakota, SDSM 8656 is from the Early Cretaceous Lakota Formation, but without better locality information its exact age was uncertain. Bjork described the material with American paleontologist David B. Weishampel in 1989 in paleontology, designating it as the new species Iguanodon lakotaensis after the Lakota people who inhabited the land and gave their name to the Lakota Formation. Weishampel and Bjork considered I. lakotaensis to share features unique to the other established Iguanodon species, I. atherfieldensis and I. bernissartensis, which are both from the Barremian of Europe. However, despite its slightly larger size than I. atherfieldensis, I. lakotaensis had fewer teeth and some other features to suggest than it was more distantly related than the two European species. Weishampel and Bjork also compared I. lakotaensis to Iguanodon ottingeri and Camptosaurus depressus, both from the Early Cretaceous of North America, but found that the limited material rendered I. ottingeri a nomen dubium and C. depressus a more distant iguanodont.