Would it be OK to use the name Thescelosauridae to accommodate not just Thescelosaurus, but also its closest relatives? With the recognition of two separate subfamilies within Thescelosauridae (Brown et al. 2013), and the erection of Clypeodonta (Norman 2014) to include all ornithopods more derived than Thescelosaurus (incl. Hypsilophodon), is it necessary to refer to Thescelosaurus as thescelosaurid?
Brown, Caleb Marshall; Evans, David C.; Ryan, Michael J.; Russell, Anthony P. (2013). "New data on the diversity and abundance of small-bodied ornithopods (Dinosauria, Ornithischia) from the Belly River Group (Campanian) of Alberta". Journal of Vertebrate Paleontology 33 (3): 495–520. doi:10.1080/02724634.2013.746229.
Norman, 2014. Iguanodonts from the Wealden of England: Do They Contribute to the Discussion Concerning Hadrosaur Origins? pp. 10-43. In David A. Eberth and David C. Evans (eds). Hadrosaurs. Proceedings of the International Hadrosaur Symposium. Indiana University Press.