didymoconodontid

Didymoconodontid is an extinct family of mammals belonging to the order Multituberculata. These animals lived during the Cretaceous and Paleogene periods, with fossil evidence found primarily in Asia and North America. Multituberculates are characterized by a unique set of teeth, including large, rodent-like incisors and a specialized premolar that functioned like a shearing blade. The name "didymoconodontid" refers to their distinctive dental features, particularly the double-lobed (didymo-) cusps on their cheek teeth.

The diet of didymoconodontids is believed to have consisted mainly of plant matter, seeds, and possibly insects, given their dentition which was adapted for grinding and shearing. They were generally small, often rodent-sized, and likely lived in diverse environments, including forests and open woodlands. Their skeletal anatomy suggests they were terrestrial, and some species may have been burrowers. The multituberculates, including the didymoconodontids, represent one of the most successful and long-lived groups of early mammals, surviving for over 100 million years. Their extinction is thought to have occurred during the Eocene, possibly due to competition from the rapidly diversifying placental mammals.