Placodontids

Placodontids are an extinct group of marine reptiles within the order Placodontia that lived during the Triassic period. They are named for their distinctive plate-like teeth used to crush shells.

Anatomy varied among placodontids. Many had broad, flattened bodies and, in several forms, armor made of dermal plates along the back. The skulls were often short with a wide snout, and the teeth were arranged into dental plates or pavement-like surfaces for processing hard-shelled prey.

Ecology and diet: Placodontids were durophagous, feeding on mollusks, brachiopods, and other invertebrates in shallow marine environments such as lagoons and coastal seas.

Temporal and geographic range: They first appear in the Early Triassic and persisted into the Middle or Late Triassic, before declining and going extinct. Fossils have been found in Europe, Asia, and North America.

Notable members include Placodus and Cyamodus, two of the better-known placodonts, illustrating the range of forms within Placodontia from primarily armored to more streamlined.