Stegoceras

• Canada

Ornatotholus is a controversial genus of bird Beck dinosaur ( Ornithischia ) from the group of Pachycephalosauria. Only species described is O. browni.

So far only the skull roof was found by Ornatotholus. This breaks down as all Pachycephalosauriern from the prefrontal ( frontal ) and the parietal ( parietal ) and has the typical for this dinosaur group thickening. The skull roof is relatively flat and has an open Supra pace Ralf Rochester (the upper cranial window of the temporal region ).

Fossil remains of this dinosaur were found in the Dinosaur Park Formation in Alberta (Canada) and first described in 1979. First, the findings were incorporated into the genus Stegoceras, 1983, described as a distinct genus Ornatotholus.

Type species and only described species is O. browni. The Fund is (late Campanian ) dated to the Late Cretaceous to an age of about 76 to 72 million years.

Whether it is a valid genus in Ornatotholus is controversial. R. Sullivan considers the findings only as juveniles of Stegoceras and assigns it to this genus; Teresa Maryańska among others they lead, however, as a separate genus and place them in a cladistic analysis because of the open cranial window as a relatively primitive Pachycephalosaurier. Clarity about will probably only bring further discoveries.