It is closely related to the extant frilled sharks in the genus Chlamydoselachus, which it can be differentiated from by tooth morphology.

Remains are known from worldwide, including Japan, Canada, Austria, New Zealand, Angola, Ecuador, and Antarctica.

[1] In addition to the genus as a whole, one individual species is also known to have survived the Cretaceous-Paleogene extinction event: R. tatere, which was first described from the Early Paleocene of New Zealand and was later also identified from the Late Cretaceous of Antarctica, extending the record of its existence by over 10 million years.

[2] R. goliath, from the Late Campanian of Angola's southern Benguela Basin, could grow to very large sizes.

This tooth is about 20mm high,[8] and is characterised by straightened, upright cusps with smooth enameloid which lack ornamentation.