THE HALL OF FOSSIL VERTEBRATES 



pigs and peccaries, camels, deer, sheep and cattle. Four skele- 

 tons and numerous incomplete specimens represent these last. 



The south side of the hall is devoted chiefly to the Perisso- 

 dactyls or Odd-toed Hoofed Mammals. First come the Titan- 

 otheres, an extinct group, once abundant in North America, 

 whose evolution is here illustrated by two skeletons and a series 

 of skulls ; then the Rhinoceroses, also abundant in North Amer- 

 ica in former geological epochs, represented here by six complete 

 skeletons and a large series of skulls; after these the Horses, 

 whose evolution is illustrated by two skeletons and many skulls 

 and feet. At the eastern end of the hall is a cast of the skeleton 

 of the Megatherium, or great Ground Sloth, the largest of a sin- 

 gular group of mammals which inhabited South America until 

 the advent of Man in that part of the world. 



Fossil Reptiles. 



The Dinosaurs, or giant reptiles, have been placed tempora- 

 rily in two wall cases at the east end of the hall, and in the two 

 high cases to the north of the centre aisle. Small models of res- 

 torations of three kinds of dinosaur will be found in an "A"-case 

 near the east end of the hall, near the centre aisle. 



These were the great terrestrial vertebrates of their day, the 

 Age of Reptiles, and they assumed an extraordinary variety of 

 forms, but all had long hind limbs and a long' and massive tail. 

 Some of the Sauropods (e. g., Brontosaurus, Diplodocus, Moro- 

 sanrus), four-footed, long-necked, herbivorous, probably amphibi- 

 ous, were beyond comparison the largest animals that ever trod 

 the earth and can be compared in size only with the modern whales. 

 Incomplete skeletons of these monstrous beasts are shown in 

 this hall. Others, the Megalosaurs, were two-footed, carnivorous, 

 preying on the clumsy giants (Sauropods) with which their 

 remains are found associated in the rock. Others again, the 

 Stegosaurs and Ceratopsians, or armored dinosaurs, were short- 

 necked quadrupeds, massively proportioned, with back and tail 

 covered by heavy bony plates and spines. Another group, the 

 Ornithopods or Iguanodonts, long-limbed bipeds — or rather 

 tripeds, for the long and massive tail formed a third support, — 



16 



