[2] Most researchers in paleobiology and paleontology now use the antecedent genus Merycoidodon to refer to this Oligocene epoch oreodont, even though it was once widely known by the younger synonym of Oreodon.

Taxonomically speaking, Merycoidodon belongs to the family Merycoidodontidae (once known as "Oreodontidae"), a group of artiodactyls related to camels that were endemic to North America.

Its ancestors date back to the Eocene and its last descendants are known from the end of the Miocene, so that oreodonts, broadly speaking, lived throughout most of the Paleogene.

Unlike modern ruminants, they had a full set of teeth, although the molars were adapted for grinding up tough vegetation.

Fossils have been uncovered from as far north as Alberta, Canada to Florida, Texas, Colorado and Oregon in the United States.