Dinocerata

Ecology

Uintatheriids are suggested to have been browsers.

Evolution

The oldest and most primitive members of the group, such as Prodinoceras, appeared virtually simultaneously during the late Paleocene in North America and Asia, indicating connection between the two landmasses, with uintatheres continuing to exchange between the landmasses during the Eocene, as suggested by the presence of Uintatherium in both North America and China. Uintatheres became extinct towards the end of the Middle Eocene, for unknown reasons.

Classification

The affinities of the group within Placentalia have historically been contentious. A 2015 phylogenetic study recovered Dinocerata as part of Laurasiatheria, closely related to ungulates and "condylarths", with Dinocerata placed as the sister group to the South American native ungulate group Xenungulata. A close relationship with Xenungulata was first proposed in 1985, with the proposed clade containing both groups named Uintatheriamorpha, though other authors have suggested that these similarities are likely to be due to convergence.

Taxonomy and phylogeny

Dinocerata is generally divided into two families, "Prodinoceratidae", containing the most primitive genus Prodinoceras, with some authors also choosing to include the genus Probathyopsis, and Uintatheriidae, containing all other genera. Members of Prodinoceratidae are likely ancestral to Uintatheriidae. The Asian uintatheriid genus Gobiatherium is often placed into its own separate subfamily Gobiatheriinae, with all other uintatheriids belonging to the subfamily Uintatheriinae.

• Order Dinocerata
  • Family Prodinoceratidae
    • Prodinoceras
    • ?Probathyopsis
  • Family Uintatheriidae
    • Gobiatherium
    • Probathyopsis
    • Bathyopsis
    • Uintatherium
    • Eobasileus
    • Tetheopsis