Massospondylidae is a family of sauropodomorphs -- close relatives of true sauropods -- that lived during the Late Triassic and Early Jurassic, roughly 210 to 183 million years ago. Members were mid-sized, bipedal-to-facultatively-quadrupedal herbivores or omnivores, typically 4 to 6 meters long, with small skulls, long necks, and hands bearing an enlarged thumb claw. Their leaf-shaped teeth suggest a plant-heavy diet, though the presence of gut-processing structures and comparatively simple dentition has kept some debate open about how much animal matter, such as insects or small vertebrates, supplemented their diet.
The type genus Massospondylus, from southern Africa, is one of the most completely known dinosaurs of the Early Jurassic, represented by skeletons, trackways, and even fossilized embryos that have informed research on early dinosaur growth and nesting behavior. Related genera include Lufengosaurus from China and Coloradisaurus from Argentina, reflecting a distribution across the still-connected supercontinent Pangaea. As one of the more diverse and geographically widespread early sauropodomorph families, Massospondylidae has played a significant role in understanding the transition from small bipedal ancestors to the giant quadrupedal sauropods of the later Jurassic.