THE COLLECTION OF FOSSIL VERTEBRATES 15 



or collateral ancestors of the modern Horses, Asses and Zebras, 

 are in one alcove, arranged in series from the most ancient to 

 the most recent. The most ancient and structurally primitive 

 groups of mammals come first, the most modern and familiar 

 types come last. 



South (Right) Side. 



TITANOTHERES 

 Chalicotheres 



Perissodactyls 



or Odd-Toed 



Hoofed 



Mammals 



Tapirs 

 -^ Lophiodonts 

 RHINOCEROSES 



Palseotheres 

 HORSES 



North (Left) Side. 

 AMBLYPODS / Primitive Hoofed 

 CONDYLARTHS f Mammals 

 Monkeys, Bats, Rodents, Insectivores 

 and other Small Primitive Mammals 

 Marsupials 



CREODONTS ) Carnivorous 

 CARNIVORES ) Mammals 

 Seals, Dolphins, Whales, } Marjne 

 Sirenians etc. ) Mammals 



MASTODONS and } 

 ELEPHANTS i 



ELOTHERES ] 

 Anthracotheres 

 Pigs and Peccaries 

 OREODONTS 

 CAMELS 



Proboscideans 



DEER etc. 

 Litopterna 

 Toxodontia 

 Typotheria 

 EDENTATA 



Artiodactyls 

 or 

 r Even-Toed 

 Hoofed 

 Mammals 



I Fossil Mammals 

 V Peculiar to South 

 America. 



SOUTH (RIGHT) SIDE. 



The south side of the hall is entirely devoted to the Peris- 

 sodactyls or Odd-Toed Hoofed Mammals in which the number 

 of toes (in the hind foot and generally in the forefoot) is either 

 I, 3 or 5, while in the other main division of hoofed animals, the 

 Artiodactyls, it is either 2 or 4; or more exactly, the axis of 

 symmetry of the foot passes through the central toe in Peris- 

 sodactyls, while in Artiodactyls it passes between two toes. 



The TiTANOTHERES comc first in the series of Perissodactyla, 

 large animals which suggest rhinoceroses in general g^^^j^ ^,_ 

 proportions, but have a differently shaped head and 

 peculiar teeth. These began as hornless animals of 

 moderate size (Cases i and 17) and increased in size 

 and developed large bony horns (Cases 3, 5 and 19) before they 



cove I. 



Titan- 



otheres 



