28 ELEPHANTS. 



Pier- the great increase in size, the neck actually shortened, and it was 

 4 j as ^ only this extraordinary lengthening of the snont that enabled 

 Table- tne an i ma l s to reach to feed or drink. 



case 28. The next stage in this strange history is found in Tetra- 

 belodon longirostris (fig. 15), an elephant of which the remains 

 are common in the Lower Pliocene of Eppelsheim in Germany 

 and other localities. In this animal the skull, so far as known, 

 does not differ to any great extent from that of Tetrabelodon 

 angustidens. The teeth, however, have advanced considerably 

 in size and complication. The first and second molars may 

 have four or five transverse ridges, while in the last there may 

 be as many as six ridges (fig. 16B). Only one of the milk- 

 molars is now replaced by a premolar, and both this and the 

 other milk-molars are early pushed out by the forward growth 

 of the large molars, only two of which at most on each side 

 remain in position in old animals. It is in the lower jaw, 

 however, that the chief changes have taken place. Here the 

 elongated anterior part (fig. 15), so striking in the last type, has 

 become shortened till it projects but little in advance of the 

 skull, and although its upper surface is still deeply grooved and 

 spout-like as in the earlier forms, the lower incisors no longer 

 meet in the middle line and prolong the spout, but are rounded 

 and separated from one another. In this animal it is clear that 

 the lower jaw was shortening up and could no longer reach the 

 ground, but doubtless the fleshy upper lip and nose, now freed 

 from their bony support for at least part of their length, 

 became flexible and better adapted for grasping the animars 

 food. In fact, this species must have looked much the same as 

 a modern elephant, except that it had a longer chin bearing a 

 pair of small downwardly directed tusks. 



In some of the American Tetrabelodons of about the same 

 age as T. longirostris, the lower tusks, instead of undergoing 

 reduction, seem to have become greatly enlarged, and at the 

 same time the symphysial portion of the mandible is slightly 

 deflected, so that the mandible with its tusks is to some degree 

 similar to that of Dinotherium. An example of this form of 

 jaw is seen in the case of the mandible of a Tetrabelodon, from 

 the Loup Fork Beds (Upper Miocene) of Kansas, exhibited in 

 pier-case 42. 



