Rhinocerotoidea

Extinct non-rhinocerotid members of the group are sometimes considered rhinoceroses in a broad sense. Although the term 'rhinoceroses' is sometimes used to refer to all of these, a less ambiguous vernacular term for this group is 'rhinocerotoids'. Rhinocerotidae are sometimes called "true rhinoceroses" to distinguish them from other rhinocerotoids.

Internal classification

Families

Rhinocerotoidea has traditionally been divided into three families: the extant Rhinocerotidae (true rhinoceroses) and the extinct Amynodontidae (swamp rhinoceroses) and Hyracodontidae (running rhinoceroses). Phylogenetic analyses often recover the traditional Hyracodontidae as paraphyletic; the giant paraceratheres, historically considered part of the family, are therefore generally recognized as the distinct family Paraceratheriidae.

Whether additional families of rhinocerotoids are recognized depends on the analysis. Historically, the basal rhinocerotoid Hyrachyus and similar forms have sometimes been placed in a family named Hyrachyidae, though recent analyses do not recover Hyrachyus in a consistent position or group. Eggysodonts are variously separated into the distinct family Eggysodontidae or retained within Hyracodontidae; whether eggysodonts and hyracodonts form a monophyletic group varies between analyses. Forstercooperia and similar forms are treated either as paraceratheres or separated into the distinct family Forstercooperiidae. Analyses similarly vary in whether forstercooperiids and paraceratheres are recovered as a monophyletic group or not.

Phylogeny

Recent analyses do not reach a consensus on interrelationships within Rhinocerotoidea. The cladograms below follow phylogenetic analyses by Bai et al. (2020), Deng et al. (2021), Veine-Tonizzo et al. (2023), and Lu et al. (2026).