Ferganastegos ("roof of the Fergana Valley, Calloviano") is a dubious stegosaurid ornithischian that lived 162 million years ago in Calloviense in the mid-Jurassic, in what is now Asia. The type and only species is named F. callovicus.
Discovery and Naming[]
Its remains come from the Balabansai Formation of the Fergana Valley in Kyrgyzstan dated to the Middle Jurassic, in the Calloviense stage.1 2 3 The holotype specimen of Ferganastegos callovicus, IGB 001, consisting of four posterior dorsal vertebrae.4 Although Averianov and collaborators did not consider the vertebrae diagnostic enough to be assigned to a genus, Russian dinosaur aficionado Roman Ulansky decided that the differences between IGB 001 and other stegosaurs were sufficient to erect a binomial name for IGB 001, Ferganastegos callovicus, which would translate as "roof of the Fergana Valley, of calloviano", despite the fact that he himself did not examine the material. Other researchers still argue that the material is not diagnostic and that the genus is a nomen dubium.