Tillodontia

Tillodontia is an extinct order of placental mammals that lived during the Paleocene and Eocene epochs. Fossil evidence of tillodonts has been found in North America, Europe, and Asia. These mammals are characterized by their large, continuously growing incisors, which likely served for digging or stripping bark. Their teeth also featured cusps that were united into broad, flattened surfaces, adapted for grinding tough plant material.

The exact evolutionary relationships of tillodonts are not fully understood, though they are generally considered to be within the superorder Laurasiatheria, possibly related to pangolins and carnivorans. The most well-known genus is Tillodon, from which the order derives its name. Other notable genera include Esthonyx and Trogosus. These animals varied in size, with some being as small as a badger and others approaching the size of a rhinoceros.

Tillodonts were likely herbivores or possibly omnivores with a diet consisting of plants, roots, and perhaps insects or small invertebrates. Their locomotion is inferred to have been plantigrade or semi-plantigrade, suggesting they walked with their soles flat on the ground. The extinction of Tillodontia is thought to be related to environmental changes and increased competition from other herbivorous mammals that arose later in the Eocene.