Article XIX.— PHYLOGENY OF THE RHINOCEROSES 

 OF EUROPE. 



RHINOCEROS CONTRIBUTIONS, No. 5.1 



By Henry Fairfield Osborn. 



By far the most striking generalization of recent mammalian 

 palaeontology is the early separation, absolute distinctness, and 

 great age of )iumerous phyla leading up to modern types. If con- 

 firmed by more detailed research, the phylogeny here proposed 

 will bring the Rhinoceroses also under this law of early diver- 

 gence ; the supposed original or stem forms having been pushed 

 steadily back into the older Cenozoic. It sets aside several 

 homoplastic characters heretofore employed in Rhinoceros evo- 

 lution and attempts to establish a firmer basis in the fundamental 

 proportions of the skull, ivhether dolichocephalic or brachy cephalic, in 

 the correlated proportions of the body, a?id in the location of the horn- 

 cores. These characters are found to be more distinctive of 

 phyla than the pattern of the molar teeth.'' 



Our present hypothesis is that, as distinguished from the 

 Amynodonts and Hyracodonts, the true tertiary and modern 

 RhinocerotidcB belong to at least six ' genetic series or phyla which 

 have no knoivn relation to each other. By Flower and Lyddeker the 

 Rhinoceroses have been placed in one genus, Rhinoceros, and 

 divided into five groups, which correspond approximately to our 

 phyla. A characteristic subfamily name is herein given to each 

 phylum, for the sake of clearness, brevity, and convenience, since 

 several of these series have a prodigious range in time, as shown 

 in the following table. 



* See Contributions 1-4, in Bibliography. 



^ The grouping proposed by Deperet (85, p. 268) and by Lydekker ('86) is partly upon 

 homoplastic characters of the teeth. 

 ^ See Osborn, 'g8, pp. 77, 121; a division of the Rhinocerotidae Xnto four subfamilies. 



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