Rhinocerotoidea is a superfamily consisting of three family groups of odd-toed ungulates, two of which, the Amynodontidae and Hyracodontidae, are extinct. The only extant family group is the Rhinocerotidae (true rhinoceroses), which survives as five living species. The extinct members of this superfamily are often called "rhinoceroses" alongside members of the family Rhinocerotidae, though they include genera, such as Paraceratherium, which do not closely resemble modern rhinoceroses.