All Dinosaurs belong to one of three orders, SAURISCHIA, ORNITHISCHIA, ot THECODONTIA. These are distinguished by the configuration of their hips, but they most likely evolved from the same ancestor. Saurischians are the lizard-hipped dinosaurs and have two suborders: THEROPODA, two legged meat eaters; and SAUROPODOMORPHA, which are gigantic quadrupedal plant-eaters as well as the smaller and more diverse prosauropods. Ornithischians, all plant-eaters, have three suborders: ORNITHOPODA, such as the duck-billed dinosaurs; THYREOPHORA, heavy-bodied ankylosaurs and stegosaurs; and MARGINOCEPHALIA, horned dinosaurs and pachycephalosaurs. THECODONTIA is a newly formed group, comparitively.

Acrocanthosaurus -- Top-Spined Lizard

Early Cretaceous, found in Oklahoma. Saurischia-Theropoda-Carnosauria

Albertosaurus -- Alberta Reptile

Late Cretaceous, found in Alberta, Canada and Oklahoma. Saurischia-Theropoda-Carnosauria

Allosaurus -- Different Reptile

Late Jurassic to Early Cretaceous, found in the Rockies, Tanzania, and Australia. Saurischia-Theropoda-Carnosauria

Anatosaurus -- Duck Reptile

Late Cretaceous, found in Alberta, Montana, and New Jersey. Ornithischia-Ornithopoda-Hadrosauridae

Anchisaurus -- Near Reptile

Late Triassic to Early Jurassic, found in Connecticut and South Africa. Saurischia-Sauropodomorpha-Prosauropoda

Apatosaurus -- Deceptive Reptile

Late Jurassic, found in Colorado, Utah, Wyoming, and Oklahoma. Saurischia-Sauropodomorpha-Sauropoda

Archaeopteryx -- Ancient Wing

Late Jurassic, found in Bavaria and Germany. Saurischia-Theropoda-Coelurosauria

Avimimus -- Bird Mimic

Late Cretaceous, found in Mongolia. Saurischia-Theropoda-Coelurosauria

Barosaurus -- Heavy Reptile

Late Jurassic, found in Utah, Wyoming, and Tanzania. Saurischia-Sauropodomorpha-Sauropoda

Baryonyx -- Heavy Claw

Early Cretaceous, found in England. Saurischia-Theropoda-Coelurosauria (maybe Carnosauria)

Brachiosaurus -- Arm Reptile

Late Jurassic, found in Colorado and Tanzania. Saurischia-Sauropodomorpha-Sauropoda

Camarasaurus -- Chambered Reptile

Late Jurassic, found in Colorado, Utah, Wyoming, and Oklahoma. Saurischia-Sauropodomorpha-Sauropoda

Camptosaurus -- Bent Reptile

Late Jurassic, found in Colorado, South Dakota, Wyoming, Utah, and Portugal. Ornithischia-Ornithopoda-Camptosauridae

Carnotaurus -- Carnivorous Bull

Early Cretaceous, found in Argentina. Saurischia-Theropoda-Carnosauria

Ceratosaurus -- Horned Reptile

Late Jurassic, found in Colorado and Tanzania. Saurischia-Theropoda-Carnosauria

Chasmosaurus -- Ravine Reptile

Late Cretaceous, found in Alberta, Canada. Ornithischia-Marginocephalia-Ceratopsia

Chirostenotes -- Slender Hands

Late Cretaceous, found in Alberta, Canada. Saurischia-Theropoda-Coelurosauria