Coelostegus is an extinct genus of Late Carboniferous (late Westphalian stage) basal reptiliomorph known from Plzeà  of Czech Republic. It is known from the holotype ÃÂGH 3027, a partial skeleton of an immature individual. It was collected in the Nýà Âany site from the Nýà Âany Member of the Kladno Formation. It was first named by Robert L. Carroll and Donald Baird in 1972 and the type species is Coelostegus prothales. Initially regarded as a reptile, subsequent research has suggested affinities with non-amniote tetrapods, closely related to Brouffia.