In 1888, a man named Harry Seeley proposed a way of classifying dinosaurs into two groups by looking at their hip structure, these groups are called Saurischia (lizard hipped) and Ornithischia (bird hipped). The two groups can be further broken down into sub-groups such as families, sub-families and so on. Let’s take a look at some of the interesting sub-groups and examples of the dinosaurs that are part of them.
Saurischia (lizard hipped dinosaurs)
Theropods - The name Theropod means ‘beast foot’ and this group includes all of the carnivorous (meat eating) dinosaurs. Although it might be surprising, birds actually evolved from Theropods rather than from Ornithischian (bird hipped) dinosaurs. Theropods moved on two legs and include a number of scary looking but popular dinosaurs such as Tyrannosaurus rex and Velociraptor.
Sauropods - Sauropods evolved to walk on four legs and typically grew to enormous sizes. They were herbivores (plant eaters) and included classic dinosaurs such as the Diplodocus and Brachiosaurus.
Ornithiscia (bird hipped dinosaurs)
Thyreophora - The name Thyreophora means ‘shield bearers’ and this group includes armored dinosaurs such as the Stegosaurus and Ankylosaurus. They were herbivores that lived from the early Jurassic Period to the late Cretaceous.
Cerapods - Cerapods included a variety of interesting groups such as Ceratopsian (horned faced) dinosaurs like the Triceratops as well as Ornithopods (bird footed) dinosaurs like the Iguanodon.