You can learn a lot about dinosaurs by looking at their bones. Some
dinosaurs were very small; others were huge. Some had sharp, pointy
teeth for eating meat; most plant-eaters had flat, dull teeth. Some
dinosaurs' hipbones pointed forward, while other dinosaurs' hipbones
pointed backward. There were dinosaurs with bony armor on their backs
and others with deadly horns on their heads. Today scientists have
divided dinosaurs into separate orders according to their special
characteristics. It's easy to see - dinosaurs are different.