Title: The dinosaur book : the ruling reptiles and their relatives
Identifier: dinosauruli13colb (find matches)
Year: 1945 (1940s)
Authors: Colbert, Edwin H. (Edwin Harris), 1905-2001; Germann, John C
Subjects: Dinosaurs; Reptiles, Fossil
Publisher: New York, N. Y. : American Museum of Natural History
Contributing Library: American Museum of Natural History Library
Digitizing Sponsor: IMLS / LSTA / METRO

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shallows, with water flying up in a high spray, and finally a quiet escape through the friendly deep waters. Many of the ornithischian dinosaurs were armored in one way or another. In the true "armored dinosaurs," the stegosaurs and ankylosaurs, there were protecting plates and spikes, which reached the climax of their development in such animals as Ankylosaurus and Nodosaurus. These dino- saurs were the armadillos of their day. When danger threatened, it was necessary only to curl up, or possibly to flatten out against the ground and let the attack rage past. These animals were not, however, merely passive defenders of their rights. Almost all of them had spikes or clubs on the end of the tail, lethal weapons of great value in beating off an attack. Some of the ornithischian dinosaurs, the troodonts, were remarkable in the protec- tion given to the brain by the skull. In these animals the skull roof became enormously massive, not through the development of sinus cavities as is usual in the vertebrates, but by the actual thickening of the bones. In one of these animals, for instance, there was a protection of some ten inches of solid, dense bone above the brain, although why such a lowly brain should need such vault- like protection is something to wonder about. The horned dinosaurs, it would seem, in- dulged in "active defense." These were the "rhinoceroses" of their day, blundering across upland glades and challenging all potential enemies by the power of their â ^ An earlier form of the boneheaded dinosaurs, Troodon, an animal only about six feet long but already showing promise of a bonehead to brag about Drawing by John C. Germann
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