Protoceratops

A sheep-sized early member of the horned-dinosaur group, Protoceratops andrewsi had a broad neck frill but lacked the long brow horns of its later relatives. About 1.8 meters long and near 83 kilograms, this herbivore is among the most common dinosaurs recovered from the Gobi Desert. Walter Granger and colleagues described it in 1923, and nests and eggs attributed to it have offered valuable evidence about ceratopsian reproduction. Living during the Late Cretaceous, roughly 100 to 66 million years ago, its abundance across all growth stages has made it a key species for studying how horned dinosaurs grew and varied within a population.