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Untitled 29 Jul 2010 
Thursday   08:08:25 
Untitled Ecosystems
Topics & Issues
Taxonomy
Animals
Birds
Plants
Internet Resources
Regions of the World Untitled
Dinosaurs
Dino Timeline
Types & Classification
Dino Myths & Misconceptions
Museums & Galleries
Dino Quiz
Photogallery & Links Untitled
Navigating Ecosystems
Ecosystems

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Dinosaurs
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Dinosaur Groups

Dinosauria includes animals whose bodies were built around two very different pelvic structures. Accordingly, Dinosauria is divided into two major groups:

Untitled Ornithischia

Untitled The Untitled Ornithischia ("bird-hipped") dinosaurs dominated during the Cretaceous Period (about 145 million-65 million years ago). The Untitled Ornithischia dinosaurs are subdivided into several major subgroups: that are subdivided further as indicated below:

  • Untitled Ornithopoda (Bird foot)

    • Untitled Euornithopoda
      • Camptosauridae
      • Dryosauridae
      • Hadrosauridae
      • Hypsilophodontidae
      • Iguanodontidae
    • incertae sedis
    • basal ornithopod

  • Untitled Marginocephalia

    • Untitled Ceratopia (Horn-faced)
      • Ceratopidae
      • Psittacosauridae

    • Untitled Pachycephalosauria (Thick-headed reptiles)
      • Pachycephalosauridae

  • Untitled Thyreophora

    • Untitled Ankylosauria (Armored reptiles)
      • Ankylosauridae
      • Nodosauridae

    • Untitled Stegosauria (Roofed or plated reptiles)
      • Huayangosauridae
      • Stegosauridae

    • basal thyreophoran

  • basal Ornithischian Untitled





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      First Written: 19990104       Latest Update: 20060328 Untitled
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