Ornithischian and Saurischian Dinosaurs Background information

Classifying Characteristics Dinosaurs are classified into one of two groups Quadripeds vs Bipeds Based on hip structure Hip is made of three bones: ilium, ischium and pubis Our focus will be on the group known as the “reptile-hipped” dinosaurs Theropods (Saurischians) Basis of your project: Are dinosaurs extinct?

Group 1: Ornithischians Dinosaurs that are quadrupeds Small heads, long necks Long tails All marine and terrestrial dinosaurs have pelvises comprised of three bones This group is identified by one of the three bones, the pubis, and its orientation. It points backward and is parallel to the ischium.(Berkeley.edu) http://www.ucmp.berkeley.edu/diapsids/ornithischia/ornithischia.html (reference for information)

Examples and explanations Stegosaurus, ankylosaurus, protoceratops, triceratops, and iguanadons are examples of this group.

Saurischian Characteristics Bipedal (walk on two legs) Lizard-hipped: Pubis orientation is key Points down or forward Intelligent Large heads, and large teeth Grasping hands Asymmetrical hands Long mobile neck Divided into two major groups Theropods carnivores Sauropods herbivores

Theopod examples: Megalosaurus

Tarbosaurus

Archaeopteryx