Until now, Triceratops was thought to be unusual among its ceratopsid relatives. While many ceratopsids—a common group of herbivorous dinosaurs that lived toward the end of the Cretaceous—have been found in enormous bonebed deposits of multiple individuals, all known Triceratops (over 50 in total) fossils have been solitary individuals. But a new discovery of a jumble of at least three juveniles the badlands of the north-central United States suggests that the three-horned dinosaurs were not only social animals, but may have exhibited unique gregarious groupings of juveniles.