Page 24 - Reptiles & Dinosaurs (Britannica Illustrated Science Library)
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20 DINOSAURS                                                                                                                                                                                         REPTILES AND DINOSAURS  21




          A Docile Vegetarian                                                                                                   Stegosaurus



                                                                                                                                    was an ornithischian dinosaur that  Stegosaurus was an easy victim for the great
                his striking dinosaur is one of the most widely                                                                     belonged to the family Stegosauridae.  predators of its time, such as Allosaurus, but
                studied in the history of paleontology. The first                                                               Its distinctive features included wide plates on  it is also believed that it may have been
                                                                                                                                its back and four spines, up to 24 inches (60
                                                                                                                                                               hunted by packs of small predators, such as
          T fossils were discovered by Othniel C.                                                                               cm) long, on its tail. The function of these  Ornitholestes. It is doubtful that Stegosaurus
          Marsh in 1877 in the American West, during                                                                            features is still under debate, but it is believed  could raise itself up on its hind legs, so it
                                                                                                                                that they served mainly for self-defense.
                                                                                                                                                               probably fed mostly on low bushes.
          the “Bone Wars.” This quadruped herbivore                                                                                                                                                STEGOSAURUS
          could measure up to 29.5 feet (9 m) long                                                                                                                                                 Stegosaurus armatus
          and weigh up to 2.2 tons (2 metric tons).                                                                                                                                                Size             29.5 feet (9 m)
          Because of its small head, it has been used                                                                                                                                              Diet             Herbivorous
          since the 19th century as a symbol of                                                                                                                                                    Habitat          Subtropical Forests
          stupidity. It was later shown that                                                                                                                                                       Epoch            Late Jurassic
          most dinosaurs had small brains and                                                                                                                                                      Range            North America
          that Stegosaurus's brain was larger
          than average.
                                                                                                                                                                                                   WHERE IT LIVED
                                                                                                                                                                                                   The first fossils were
                                                                                                                                                                                                   found in Colorado.
                                                                                                                                                                                                   Other specimens have
                                                                                                                                                                                                   since been found in
                                                                                                                                                                                                   India, western
                                                                                                                                                                                                   Europe, southern
                                                                                                                                                                                                   Africa, and China.





                                                                                                                                                    Tail
                                                                                                                                                    Stegosaurus's only
                                                                                                                                                    real defense was likely
                                                                                                                                                    the four spines on its
                                                                                                                                                    tail, which it swung
                                                                                                                                                    back and forth.










                    Head
                    Its lightweight head had
                    small teeth that were of
                    little use for chewing, so it
                    swallowed plants whole.

                                                                                                                                              PLATES
                                                                                                                                              These triangular bony
                                                                                                                                              structures were not very
                                                                                                                                              solid, but they had a
                                                                                                                                              complex network of veins.
                                                                                                                                              The plates were likely used
                                                                                                                                              to regulate the animal's
                                                                      Legs                                                                    body temperature or even      Dorsal Plate              Caudal Plate         Cervical Plate
                                                                      Its front legs were                                                     for courtship.
                                                                      half as long as its
                                                                      hind legs. Each
                                                                      foot had five wide,
                                                                      short toes.
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