194 The Palaeontological Record. I. Animals 



America until a very late period. Interesting side-branches of this 

 line have also been found, one of which ended in the upper Miocene 

 in animals which had almost the proportions of the giraffes and must 

 have resembled them in appearance. 



The American Tertiary has yielded several other groups of 

 ruminant-like animals, some of which form beautifully complete 

 evolutionary series, but space forbids more than this passing mention 

 of them. 



It was in Europe that the Artiodactyla had their principal 

 development, and the upper Eocene, Oligocene and Miocene are 

 crowded with such an overwhelming number and variety of forms 

 that it is hardly possible to marshal them in orderly array and 

 determine their mutual relationships. Yet in this chaotic exuberance 

 of life, certain important facts stand out clearly, among these none is 

 of greater interest and importance than the genealogy of the true 

 Ruminants, or Pecora, which may be traced from the upper Eocene 

 onward. The steps of modification and change are very similar to 

 those through which the camel phylum passed in North America, 

 but it is instructive to note that, despite their many resemblances, 

 the two series can be connected only in their far distant beginnings. 

 The pecoran stock became vastly more expanded and diversified than 

 did the camel line and was evidently more plastic and adaptable, 

 spreading eventually over all the continents except Australia, and 

 forming to-day one of the dominant types of mammals, while the 

 camels are on the decline and not far from extinction. The Pecora 

 successively ramified into the deer, antelopes, sheep, goats and oxen, 

 and did not reach North America till the Miocene, when they were 

 already far advanced in specialisation. To this invasion of the 

 Pecora, or true ruminants, it seems probable that the decline and 

 eventual disappearance of the camels is to be ascribed. 



Recent discoveries in Egypt have thrown much light upon a 

 problem which long baffled the palaeontologist, namely, the origin of 

 the elephants 1 . Early representatives of this order, Mastodons, had 

 appeared almost simultaneously (in the geological sense of that word) 

 in the upper Miocene of Europe and North America, but in neither 

 continent was any more ancient type known which could plausibly be 

 regarded as ancestral to them. Evidently, these problematical animals 

 had reached the northern continents by migrating from some other 

 region, but no one could say where that region lay. The Eocene and 

 Oligocene beds of the Fayoum show us that the region sought for is 

 Africa, and that the elephants form just such a series of gradual 

 modifications as we have found among other hoofed animals. The 



1 C. W. Andrews, "On the Evolution of the Proboscidea," Phil. Trans. Eoy. Soc. 

 London, Vol. 196, 1904, p. 99. 



