48 Department of Vertebrate Falceontology. 



22. Primitive Sabre-tooth Tiger Hoplophoneus. 



Oligocene Epoch. 



The most striking difference between Sabre-tooth Tigers and 

 the great living cats is in the long, flattened sabre-like upper 

 canine teeth, which in Smilodon (Restoration No. 31) were 

 seven inches long. These teeth could pierce the hides of 

 rhinoceroses and other thick-skinned animals common in 

 America in the Oligocene Period, against which the shorter 

 fangs of modern lions would be ineffective. The legs were 

 shorter and more muscular than those of the larger modern 

 cats, the animal more powerful, but by no means as swift- 

 footed. 



Scott & Osborn, Bvill. Harv. Mus. Comp. Z06I., 1887, p. 153, pi. i. 

 RiGGS, Restoration of Hoplophoneus occidentalis, Kans. Univ. Quar., 

 V, 1896, pp. 37-52, pi. i. 



23. Short-legged American Rhinoceros Teleoceras. 



Upper Miocene Epoch. 



Teleoceras, the last known survivor of the Rhinoceros race 

 in America, was also the largest ; and its fossil remains are so 

 abundant in certain localities as to indicate that it lived in 

 great herds upon the plains, like the Bison in more modern 

 times. 



The body was as long and heavy as that of the living Indian 

 Rhinoceros, but the legs were so short that the belly nearly 

 reached the ground, giving the animal the squat proportions of 

 the Hippopotamus. The male had a small horn on the end 

 of the nose; the female was hornless. 

 Osborn, Complete Skeleton of Teleoceras fossiger, Bull. Am. Mus. Nat. 



Hist., X, 1898, pp. 51-59, pU. iv, iva. 

 WiLLiSTON, Kestoration oi Aphelops fossiger, Kans. Univ. Quar., 1894, 



p. 289, pi. viii. 

 Scott & Osborn, Bull. Harv. Mus. Comp. Zool., pp. 92-99, pi. ii. 



24. Amphibious Dinosaur Brontosaurus. 



Upper Jurassic Period. 



In the Reptilian Age, preceding the Age of Mammals, great 

 reptiles were dominant on land and water. The Dinosaurs, or 



