THE RESTORED SKELETON OF LEPTAUCHENIA 



DECORA. 



By WILLIAM J. SINCLAIR. 

 (Read April 22, 1910.) 



A recent examination of the Leptauchenia material in the 

 Princeton University collection has made possible the presentation 

 of the accompanying restoration of the skeleton (Fig. i), together 

 with some notes on the structure of this animal. Parts of two 

 species are represented, referable apparently, to Leidy's L. decora 

 and nitida respectively. All the specimens were collected some 

 years ago by Mr. J. B. Hatcher at Corral Draw, in the White River 

 badlands of South Dakota. 



In a general way, there is a good deal of resemblance between 

 the writer's restoration of Leptauchenia (Fig. i) and Peterson's 

 reconstruction of Phenacoccrhis,^ an animal about one fourth larger, 

 presumably related both to the first mentioned genus and to 

 Cyclopidius. The major portion of the skeleton is drawn from 

 two individuals of Leptauchenia decora (Nos. 10753, '^^77?) Prince- 

 ton University collection) supplemented occasionally by other speci- 

 mens of the same species. The fore foot is from a somewhat 

 smaller individual of L. decora (No. 10770) while the hind foot, 

 with the exception of the tarsus, is enlarged to scale from L. nitida 

 (No. 10765). On the whole, the restoration recalls to mind an 

 animal of somewhat pig-like proportions due to the large head, 

 short limbs and short tail which may have been longer than indi- 

 cated. No certain conclusion can be drawn from the skeleton 

 as a whole regarding the habits of the animal. That it was aquatic 

 inferred from the prominent rim of the auditory meatus implying 

 a " valvular closure of the organ of hearing " to prevent the inflow 



^ Peterson, O. A., " The Miocene Beds of Western Nebraska and Eastern 

 Wyoming and their Vertebrate Faunae," Annals of the Carnegie Museum, 

 Vol. IV.. No. I, p. 32, Fig. 5, 1907. 



196 



