Complex sentence: Widely distributed across western North America, especially in the coasts and coastal plains, it was a herbivore with small solid or fleshy crests that could move on two legs or four, and is thought to have lived in groups.
Split into simpler sentences: Widely distributed across western North America, especially in the coasts and coastal plains, it was a herbivore with small solid or fleshy crests. It could move on two legs or four, and is thought to have lived in groups.