PALEONTOLOGY 



321 



Trilophodon. — 'Trilophodon, a great migrant and consequently wide- 

 spread over several continents as stated above, exhibited in several re- 

 spects a striking advance over Palseomastodon ; but this advance was 

 in the main in the same direction as was indicated by the change from 

 Moeritherium to Palseomastodon. Trilophodon was a huge animal, 



Fig. 218. — Evolution of the head and molar teeth of the mastodons and elephants. 

 The skulls on the right are enclosed in the flesh in the form the latter is supposed to have 

 had. A, A', Elephas, Pleistocene; B, Stegodon, Pliocene; C, C, Mastodon, Pleistocene; 

 D, D', Trilophodon, Miocene; E, E', Palseomastodon, Oligocene; F, F', Moeritherium, 

 Eocene. {From Lull's Organic Evolution, courtesy of Macmillan Co.) 



nearly as large as modern Indian elephants. The tusks were consider- 

 ably longer (Fig. 21S,D'), and still bore a band of enamel. The molar 



