The Dinosaurs of Wyoming - Wyoming State Geological Survey ...

More documents

Recommendations

Info

82 THE DINOSAURS OF WYOMING decessor in the rocks. O. armatus would seem, therefore, to belong to a different phylum, in many respects more conservative than the true stegosaurs. "That Stegosaurs belonged to the predentate dinosaurs and to the armored Stegosauria, is certain. It is not, however, in the direct line of descent, but rather an over-specialized side branch, which was apparently totally blotted out after Morrison time, despite the fact that most of its associates, except the Sauropoda, lived on. "The spinescent character of Stegosaurus is of course indicative of racial senility, but the modernizing of the flora and the restriction, doubtless, of the special food plant to which the feeble mouth armament was adapted, may have been the immediate cause of extinction." J
CHAPTER XVI The Amphibious Dinosauria The amphibious dinosaurs are known to paleontologists as members of the Sauropoda (Figure 4). These were the giant reptiles, tall of body and extremely long. They were the largest land animals which ever lived, being exceeded only in bulk by some of the modern whales. The sauropod dinosaurs were all four-legged, with the hind legs usually the larger, but one genus, called by Riggs the Brachiosaurus, had longer fore limbs. The head was very small (Figure 30), with blunt teeth. The neck was long and slender, with an elephantine body and a long tail, which in one genus, Diplodocus, stretched out into an almost unbelievable slender length, justifying the term "whip-tail" dinosaur (Figure 31). We believe the body to have been covered by a coarse, rough, but not scaly hide, of great thickness. Like the elephants they had five short toes on each foot, probably buried in life in a large soft pad, but the inner toes had large claws, blunt like those of modern turtles, one in the fore foot, three in the hind _oot. Sauropod dinosaurs had a world-wide distribution, but in spite of this their appearance is geologically abrupt. We assume that they were derived from some of the carnivorous dinosaurs, because the theropods, as the carnivores are called, were predecessors of the sauropods. The sauropods had a short existence, geologically, being confined to the closing portions of the Jurassic and the Lower Cretaceous, in a period called the Comanchean. Many carnivorous, armored, and beaked dinosaurs lived at the same time with the sauropods, and are found in the same strata of rocks. Skeletons of various amphibious dinosaurs are mounted in a number of the larger natural history museums. One of the largest skeletons mounted in the American Museum of Natural History in New York City was discovered near Medicine Bow, Wioming. It is sixty-six feet long and when alive some paleontologists think the animal may have weighed about thirty-eight tons. It is seldom the case that such huge bodies were buried and fossilized and collected in a perfect condition, so that mounted skeletons are usually a combination of two or more individuals, and even then some of the 83
Page 1 and 2:
'The CVinosaurs of Wyoming By ROY L
Page 3:
Tragedy of the Mesozoic All the ele
Page 6:
The DINOSAURS of Wyoming By ROY L.
Page 10 and 11:
LIST OF ILLUsTRA'frONS IX Figure 32
Page 12 and 13:
PREFACE The subject of dinosaurs in
Page 15:
CHAPTER 1. What Are the Dinosaurs?
Page 18 and 19:
2 CHAPTER II The Geological Age of
Page 21 and 22:
CHAPTER III Their Origin and Distri
Page 24 and 25:
THEIR ORIGIN Ai"D DISTRIBUTIOK 23 A
Page 27 and 28:
CHAPTER IV Historical Account of th
Page 29 and 30:
28 THE DINOSA1.:RS OF WYOMING "How
Page 32 and 33: 92 THE DIKOSAURS OF 'WYOMING of bro
Page 34 and 35: 94 THE DI OSAURS OF WYOMI G small p
Page 38 and 39: 'C '" FIGURE 40.-DISEASE AND INJURY
Page 40: FIGURE 41.-INJURIES AMO"G FOSSIL VE
Page 43 and 44: FIGURE 42.-FRACTURE 'AND NECROSIS I
Page 47: THE THREE-HORNED DINOSAURS 107 horn
Page 50: CHAPTER XIX Animals Which Lived wit
Page 53 and 54: CHAPTER XX Wyoming Dinosaurs Abroad
Page 58 and 59: CHAPTER XXII QLOSSARY Amphibious Di
Page 63: "SACRAL BRAIN" OF DIi\TOSAURS depar
Page 67 and 68: CHAPTER XIV Footprints of Dinosaurs
Page 70: CHAPTER XV The Armoured Dinosauria
Page 73 and 74: THE ARMOURED DIKOSAURIA 73 of penta
Page 75 and 76: "
Page 78 and 79: FIGURE 25.-RESTORATION OF THE PALAE
Page 80 and 81: 80 THE DINOSAURS OF WYOMING The lif
Page 84: I- I 84 THE DINOSAURS OF WYOMING mo
Page 88 and 89: CHAPTER XVII The Carnivorous Dinosa
Page 90 and 91: 90 THE DINOSAURS OF WYOMING Carniyo
Page 94 and 95: 58 THE DINOSAURS OF WYOMING out lif
Page 98 and 99: 32 THE DIN"OSAURS OF WYOMIN"G bette
Page 100 and 101: 34 THE DINOSAURS OF WYOMING tured i
Page 102 and 103: 36 THE DINOSAL"RS OF WYOMING publis
Page 104 and 105: 38 THE DINOSACRS OF WYOMING The hug
Page 106 and 107: 40 THE DINOSAURS OF WYOMING Wyoming
Page 109 and 110: FIGURE 8. Map of Niobrara County. W
Page 111: DIFFERENT KINDS OF DIKOSACRS 45 "Co
Page 115 and 116: FIGURE IO.-PATHOLOGICAL LESIONS IN
Page 117 and 118: FIGURE
Page 119 and 120: FIGURE 14. The Haemangioma. or vasc
show all

The Dinosaurs of Wyoming - Wyoming State Geological Survey ...

Create successful ePaper yourself

Delete template?

Save as template?