dimetrodon: meaning, definition, pronunciation and examples

No, dimetrodon was not a dinosaur. It is a synapsid, a group more closely related to mammals, and lived during the Permian period, 40-50 million years before the first dinosaurs appeared.

The name comes from Greek: 'di-' (two), 'metron' (measure), and 'odon' (tooth), referring to its two distinct types of teeth (canines and incisors), a trait more common in mammals than reptiles.

The leading hypothesis is thermoregulation; the sail, filled with blood vessels, could have been used to absorb heat from the sun or to radiate excess heat to cool the animal down. Other theories include display for mating or intimidation.

Fossils have been found primarily in the southwestern United States, in areas that were floodplains during the Permian period, such as the Red Beds of Texas and Oklahoma.

A large, extinct, early Permian synapsid (mammal-like reptile) known for its distinctive elongated neural spines forming a sail-like structure on its back.

Dimetrodon is usually technical/scientific in register.

Dimetrodon: in British English it is pronounced /daɪˈmiːtrədɒn/, and in American English it is pronounced /daɪˈmɛtrəˌdɑːn/. Tap the audio buttons above to hear it.