Plateosauridae is a family of Late Triassic sauropodomorphs, among the largest land animals of their time, typically reaching 6 to 10 meters in length. They were bipedal or facultatively quadrupedal herbivores with long necks, small heads, leaf-shaped teeth suited to processing plant material, and a large thumb claw on each hand that may have served in defense or foraging. Numerous well-preserved skeletons, particularly of the type genus Plateosaurus from Germany and Switzerland, have made this family one of the best-studied groups of early dinosaurs, with bone histology studies revealing details of their growth rates and the possibility that individuals grew at variable speeds depending on environmental conditions.
Plateosaurids lived roughly 214 to 204 million years ago and are known primarily from Europe, with mass accumulations of Plateosaurus skeletons at sites such as Trossingen suggesting herd behavior or repeated deaths at the same location, possibly a mud trap or drought refuge. As one of the dominant large herbivores of the Late Triassic, before true sauropods became widespread, Plateosauridae represents an important stage in the early diversification of the sauropodomorph lineage that would eventually produce the largest animals ever to walk on land.