Phalarodonidae

Phalarodonidae is a family of extinct mammals belonging to the order Artiodactyla, the even-toed ungulates. These animals are known from fossil remains found primarily in North America. They are characterized by a distinctive dentition, particularly the presence of hypsodont molars which are adapted for grinding tough plant material. The snout of Phalarodonidae was relatively short, and their limbs suggest they were capable of both running and browsing.

The evolutionary relationships of Phalarodonidae have been a subject of study, with their placement within Artiodactyla generally accepted, though their exact position relative to other artiodactyl suborders has been debated. Some researchers have placed them closer to ruminants, while others suggest a more basal position within the group. They are believed to have lived during the Eocene and Oligocene epochs.

Fossil evidence indicates that Phalarodonidae were herbivores. The wear patterns on their teeth suggest a diet consisting of grasses and other fibrous vegetation. The geographical distribution of their fossils points to them inhabiting a range of environments, likely including open woodlands and grasslands. The extinction of Phalarodonidae is thought to be related to environmental changes and competition with other herbivorous mammals that emerged during the Cenozoic era. Their disappearance marks a transition in the mammalian fauna of North America.