The head of "Prenocephale" was comparable to that of "Stegoceras", albeit with closed supratemporal fenestrae. Also, the paired grooves above the supraorbitals/prefrontals (along with a posterior parietal that restricts the frontal dome) are absent in "Prenocephale". This differentiates the species from "Stegoceras", as such features are common in the latter. The North American "Sphaerotholus" was considered a synonym of "Prenocephale" by Sullivan (2003), but Longrich et al. (2010) and Schott and Evans (2016) kept it as a distinct genus based on cladistic analysis. "Homalocephale" has been viewed as a possible juvenile of "Prenocephale" due to the lack of a dome and its discovery in the same location and chronological interval, but new specimens of "Prenocephale", including a juvenile specimen, suggest that "Homalocephale", even if its holotype is a juvenile, is distinct.