Coelophysidae is a family of small, lightly built theropods that lived during the Late Triassic, roughly 216 to 196 million years ago, making them among the earliest dinosaurs known in any detail. Diagnostic features include a long, low skull with slender, blade-like teeth, an elongated neck and tail, hollow limb bones, and a gracile build suited to speed over power. Most species measured under 3 meters long and likely hunted small vertebrates and insects in fast-moving packs or loose aggregations, an inference drawn partly from the mass death assemblage at Ghost Ranch, New Mexico, which preserved dozens of individuals of the type genus Coelophysis together.
The family's fossil record spans North America, southern Africa, and possibly Europe, reflecting the largely unbroken Pangaean landmass of the period. Beyond Coelophysis itself, the family includes genera such as Megapnosaurus (formerly grouped with Syntarsus) from Zimbabwe and Arizona, and Camposaurus from the American Southwest. Coelophysids sit near the base of the theropod family tree, and their anatomy -- particularly the shape of the skull and vertebrae -- has made them an important reference point for understanding how the earliest carnivorous dinosaurs were built before the group diversified into the much larger predators of the Jurassic and Cretaceous.