A NEW RESTORATION OF A TITANOTIIERE 17 



known evolutionary history in the first hah' of the Ao;c of Manunals. The 

 last and greatest member of the titanotheres is the flat-horned Bmiitofhcrium 

 platycera.s, and a hrief review of our reasons for representing,' this animal 

 as it here appears may serve to illustrate one or two principles in the art 

 of restoring- extinct animals. The skull was first modeled in clay from a well- 

 preserved fossil specimen. The clay to represent the flesh was then laid in 

 on one side of the skull model, the other side being left exposed temjjorarily 

 to show the .supposed relations between skull contour and external form. 



The top and sides of the head offered no especial difficulty, since the 

 location of the principal muscle-masses of the temporal region and jaws could 

 be inferred by comparison with the corresponding parts in the skulls of 

 recent rhinoceroses and other distant relatives of the brontothere. The 

 flattened "horns" (bony outgrowths from the skidl) for various reasons 

 were represented as covered with \ery tough hifle rather than with true horn. 

 The nose and nostrils were restored after careful comparison with many 

 animals, especially the "black" rhinoceros, whose bony nasal region is 

 essentially similar to that of the brontothere. 



The most difficult part is the mouth and here present-day animals offer 

 some at first rather contradictory evidence. In both the "l)lack" and the 

 "white" rhinoceroses of Africa the front teeth of the upper and lower jaws 

 are lacking in the adult and the corresponding bony parts are reduced. 

 From this similarity we might be led to expect that the lips of the two were 

 also similar. And yet, as a matter of fact, the "black" rhinoceros in 

 adaptation to its habits of plucking up roots and shrubs, has a pointed or 

 prehensile upper lip; while in the "white" rhino, which feeds exclusively 

 upon grass, the upper lip is very broad and square. The Asiatic rhinoceros, 

 which feeds in the "grass jungles," has large cutting upper incisors and 

 divergent lower tusks; its iipper lip is pointed, but less than in the "black" 

 species. These examples indicate that at least in the rhinoceroses the shape 

 of the upper lip depends less upon the form and arrangement of the front 

 teeth than upon the nature of tlie food and the mode of tearing it up from 

 the ground. 



The grinding teeth of the brontothere seem to be fitted to crush and cut 

 up vegetation of a somewhat coarser nature than the tender shrul)s and 

 roots which form the principal food of the "black" rhino. Still less was 

 the brontothere a true grazer, for in comparison with the "white" rhino, 

 its grinders had low crowns and lacked the "cement" which is so character- 

 istic of the teeth of grass-loving ungulates. Also its front teeth were 

 feeble, their prehensile functi(m being very possibly usurped l)y a heavy 

 upper lip. Hence it seems probable that the brontothere fed on coarse 

 shrubs and roots and had a heavy, prehensile upjjer lip; accordingly it 

 is this type of lip which Mr. Christman has given to his model. 



