Romer considered Younginidae to include many genera that are no longer classified as younginids: Paliguana, Palaegama, and Saurosternon are now considered basal lepidosauromorphs, Galesphyrus and Heleosuchus are diapsids of uncertain affinities (incertae sedis), Heleophilus is now a milleretid, andHeleosaurus is now thought to be a varanopid synapsid.