208 R. S. Lull— Evolution of the Elephant. 



tese elephants the diminution in size brings the animal helow 

 the stature of the ancestral Moeritherium, though in no other 

 way is it an atavistic type. Dwarf forms are also found in 

 Crete and Cyprus. 



An earh T form of Elephas antiquus evidently gave rise to 

 the modern African elephant through the type known as 

 Elephas priscus, included by some authorities in E. antiquus 

 itself. The development of teeth of E. africanus with rela- 

 tively few lozenge-shaped ridges seems to be a matter of 

 degeneracy which casts some doubt upon the value of the 

 subgenus Loxodonta. Elephas africanus deployed over the 

 whole of Africa with the exception of the Sahara desert. It 

 also crossed to Gibraltar and spread over most of the Spanish 

 peninsula. It has since been extirpated, however, in all of the 

 region north of the Sahara. The living Indian elephant 

 exhibits similarity of structure with the E. antiquus, a form 

 known as Elephas armeniacus, found in Asia Minor, being 

 annectent type. Elephas indicus may have come from Ele- 

 phas insignis through the Lower Pleistocene E. hysudricus, 

 and probably represents a purely local evolution, not a migra- 

 tory form. 



A most perplexing question arises with reference to the ori- 

 gin of the great North American elephants, Elephas imperator, 

 E. columbi and finally E. primigenius itself. Emphasis has 

 been placed on the similarity existing between the American 

 and European elephants, though I know of no expression of 

 opinion as to the actual relationship of the forms in cpiestiom 

 In tooth characters Elephas columbi is certainly suggestive of 

 its European contemporary E. antiquus, while E. imperator 

 somewhat resembles E. meridionalis". The tusks which are so 

 important from the developmental standpoint have apparently 

 been ignored, for the American types have huge spiral tusks, 

 while those of Elephas antiquus are nearly straight, and. in 

 E. meridionalis they show by no means the development of 

 E. imperator. It is the writer's opinion that the American 

 forms may prove to be a distinct evolution, having been 

 derived from some such form as Elephas planifrons, found in 

 India from the Pliocene of the Siwalik hills to the Pleisto- 

 cene of Narbada valley. We have no record of the migration 

 of E. planifrons, but its progenitors and contemporaries 

 ranged, in some cases, as far as China and Japan by way of 

 Burma. This being an accustomed route, E. planifrons or a 

 successor might well have ventured beyond China to the north- 

 east through Siberia, across the Behring isthmus and thence 

 southward as far as Mexico, giving rise to the American form 

 Elepjhas imperator, which is first reported from the Equus or 

 Sheridan beds (Lower Pleistocene). The known range of the 



