(class Reptilia, subclass Euryapsida)
An order of Triassic reptiles which were specialized shellfish feeders. Some were heavily armoured and strongly resembled turtles; while the more lightly armoured varieties, e.g. Placodus, were analogous in general form to the Nothosauria, except for the modifications relating to their molluscan diet. Placodus impressus had large, flat teeth on the palate and lower jaws, webbed fingers and toes, and an elongate tail, and was adapted to feeding on shell banks. Later representatives of the placodont reptiles were more turtle-like.
Subjects: Zoology and Animal Sciences.