FOSSIL RHINOCEROS (DICERATHERIUM ARMATUM 

 MARSH) FROM GALLATIN COUNTY, MONTANA 



By Horace Elmer Wood, 2d 



Dana College, Newark, New Jersey 



The United States National Museum has in its collections a partial 

 skull of a rhinoceros (No. 11682), consisting of the front with nasals 

 and most of the upper cheek teeth. Associated are two skuU frag- 

 ments, one including the right glenoid region, the other the left glenoid 

 region, the skull roof, and the basisphenoid. The material was col- 

 lected by C. A. Kinsey, of Belgrade, Mont., about 2 miles south by 

 west of the present town of Three Forks and IK or 2 miles west of the 

 Madison River. The position (see 1928 U. S. Forest Service map of 

 Gallatin National Forest) is in sec. 11, T. 1 N., R. 1 E., at the end of 

 a point jutting out from the western side of the bench in the fork of 

 the roads south from Three Forks. On the Three Forks sheet of the 

 United States Geological Survey topographic map, edition of 1895, 

 reprinted in 1920, Three Forks occupies its former position. The 

 locality, on this map, is situated near the northern end of the intermit- 

 tent stream that drains toward the Jefferson River, between the 

 Madison River and Willow Creek. The nearest outcrops of the Mad- 

 ison Valley formation on the east bank of the Madison River are 2}i 

 to 3 miles to the east. 



With exemplary public spirit, Mr. Kinsey presented this material 

 to the United States National Museum. He furnished the data 

 regarding the locality and sent me, for study, the other rhinoceros 

 material from this region, referred to in this paper. C. W. Gilmore 

 kindly submitted the specimen to me for description. I am indebted 

 to Prof. C. C. Mook, who checked my interpretation of the stratig- 

 raphy of this occurrence on the basis of his personal acquaintance 

 with the region. 



The skull in question (see pis. 1-3) is that of one of the larger Amer- 

 ican pair-horned rhinoceroses, and is clearly referable to the genus 

 Diceratherium in the restricted sense. It is equally clear that it is 

 close to the type species, D. armatum Marsh. (For figures of the type 

 of D. armatum, see Peterson, 1920, fig. 10 and pi. 57; also Troxell, 

 1921, fig. 5.) The tooth pattern is rather simple. All four premolars 

 have their cross-lophs complete and parallel. Except for the mures, 



No. 2948. — Proceedings U. S, National Museum, Vol. 82, Art. 7 



160258—33 1 



