i6 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6l 



VERTEBRAL FORMULA OF THE LIVING SPECIES OF 

 RHINOCERATID.E. 



Species 



Ceratotherium s. 

 simum. 



Do 



Ceratotherium simum 



cottoni. 

 Diceros bicornis 



Do 



Do 



1) 



Do... 



Locality 



Mas lion aland 

 Africa. 



South Africa 



Lado Enclave. . 



Abyssinia 



do 



do 



do 



South Africa. 



Dicerorhinus suma- I Malacca. 

 trensis. 



Rhinoceros unicornis. 'India 



Do ! do .. 



Do I do .. 



Rhinoceros sondaicus. Java 



Museum 



Sex 

 and 

 age 



British . 



Paris . . . 

 Congo . . 



British . 

 ...do... 

 ...do... 

 ...do ... 

 Paris . . . 

 British . 



Paris ... 



British . 

 ...do... 

 ...do.., 



cfad. 



? ad. 

 cfold 



ad. 

 ad. 

 9 ad. 

 ad. 

 ad. 

 J aged 



dad. 

 aged 

 aged 

 ad. 



Vertebrae 



Caudal 



2 16 



'20 

 23 



Want'g 

 26 



3 16 



1 Bones irregular, showing substitution and duplication. 



2 Lacking at least one of the anterior vertebrae. 



3 Several apical vertebrae wanting. 



DERIVATION 



In attempting to determine the closest fossil allies of the square- 

 nosed rhinoceros we are at the very outset balked by the bewildering 

 combination of characters displayed by the fossil species. The com- 

 binations of skull characters assumed by the late Tertiary and Pleisto- 

 cene species do not seem to point to any definite lines of evolution, and 

 moreover, are so diverse as to be of generic importance, practically 

 forcing the recognition of a large number of monotypic genera. 

 Osborn * in his monograph on the genera attempted to infuse order in 

 the family Rhinoccratidcc by dividing the species into six groups, 

 using skull and horn characters rather than dental. He has expressed 

 his dismay at the result in these words : " If this or some similar phy- 

 logenetic hypothesis can be established it will not elucidate the origin 

 which remains an enigma, but it will at once simplify the whole 

 problem of the succession, development, migration, and taxonomy of 

 this baffling group." The absence of any obvious clues to the evolu- 

 tion of the various groups point conclusively to the fragmentary 

 character of the paleontological record. The fundamental diversity 

 of most of the genera must be due largely to the great age of the 

 groups which they represent. The fossil forms range geographically 

 through America, Europe, Asia, and Africa. Geologically, they 

 occur from the Oligocene to the present. The very oldest genera 



1 Bull. Am. Mus. Nat. Hist., 1900. 



