180 EVOLUTION IN THE PAST 



and short-snouted, abounded. Among long-snouted forms 

 ancestors of the modern Ganges gavials were to be seen (G. 

 gangeticus). Some members of this species were formidable 

 creatures, much larger than their present-day descendants. 

 But they were surpassed in their day by monsters over 

 fifty feet in length, belonging to a species now long extinct 

 (Rhamphosuchus'). Hippopotamuses, one might suppose, 

 must have found such giants unpleasant bathing companions. 

 It is stated, however, by recent travellers that hippopotamuses 

 and crocodiles live on excellent terms with one another. 

 Possibly this " mixed " bathing was innocently carried 

 on in Pliocene times. 



TORTOISES No less remarkable for size were some of the tortoises. 

 Remains have been found of one of these animals whose 

 shell was eight feet in length (Colossochelys atlas}. This huge 

 creature, safe in some insular habitat, must have died full 

 of years possibly at an age of three hundred. 



NORTH A journey must now be made from Asia to North America. 

 AMERICA This, as already stated, could be accomplished entirely on 

 land. Unfortunately but little is known of the " new " 

 world life at this time. As in India, among horses with 

 diminishing " extra " toes some one-toed forms were to be 

 seen. Rhinoceroses never successful in this part of the 

 world were dying out. By reductions in number both of 

 teeth and toes these animals had certainly drawn nearer 

 to modern rhinoceroses, but they all continued hornless 

 (Aphelops}. American rhinoceros-life, therefore, went down 

 to its grave with no slight imperfections on its head. Some 

 descendants of the early camel-like creatures had now 

 definitely developed into lamas (Auchenia). Descendants 

 of some of the Miocene pig-like creatures had distinctly 

 emerged as peccaries (Dicotyles) ; and old-fashioned elephants, 

 long-chinned and four-tusked (Tetrabelodon), were now sup- 

 plemented by forms of Mastodon type (Dibelodon). 



Burrowing beaver-squirrels, horned on the snout such 

 as appeared in North America in the Miocene were still 

 in being (Mylagaulus), and new species had arisen (Epigaulus). 

 From some unknown cause all these curious underground 

 workers became extinct at the close of this epoch of the 



