S4 The BacMand Formations of the BLack Hills 1 Region 



Lower Miocene. 



Nimravus sect at or, Matthew. 



MUSTELIDAE. 



The Mustelidae of the present day include the badgers, 

 martens, weasels, ermines, skunks, otters, ratels, etc. Fossil 

 members of the family have been found in some abundance. 

 The more ancestral forms continue back to Eocene time, but no 

 clearly defined species have as yet been identified in the badland 

 formations of the Black Hills region in rocks older than the 

 Miocene. Their description is confined to the recent writing 

 of Mr. W. D. Matthew and of Mr. O. A. Peterson.* 



Matthew first described, 1904, a fragmentary lower jaw, 

 Potamotherium lacota, and a perfect lower ]aw,Lutrina pris- 

 tina, from the Upper Miocene of Little White river. Peterson, 

 1906, described part of a lower jaw , Brachypsalis simplicidens, also 

 a poorly preserved skull, lower jaw, and other bones of Aeluro- 

 cyon brevifacies, from the Harrison beds of" Sioux County, 

 northwestern Nebraska. Later, 1907, Matthew described a 

 lower jaw and a portion of the skull of Oligobunis lepidus, also 

 the skull, jaw and considerable parts of the skeleton of Megalic- 

 tis ferox from the Lower Miocene of Little White river. 



None of the remains discovered are complete, and nearly 

 all are more or less mutilated. Those of Megalictis ferox, 

 however, are sufficiently characteristic to indicate much of the 

 nature of the animal. They represent a very large musteline. 

 The head is short, wide, and massive, brain small, tail long and 

 powerful, limbs short and stout, feet plantigrade, number of toes 

 five, claws large and non-retractile. The animal is characterized 

 as a gigantic wolverine, equalling a jaguar or a black bear in 

 size, but in proportion more like the ratel. It was evidently 

 predaceous like the wolverine, but seems to have been to some 

 degree of burrowing disposition. 



INSECTIVORA 

 Remains of insectivorous animals are recognized as far 



* Matthew, W. D., and Gidley, J. W. New or Little Known Mam- 

 mate from the Miocene of South Dakota. Bull. Am. Mus. Nat. Hist., 

 Vol. 2 0, 1904, pp. 2 41-2 71. 



Peterson, O. A. The Miocene Beds of Wiestern Nebraska and 

 Eastern Wyoming and Their Vertebrate Fauna. Annals Carnegie Mus., 

 Vol. 4, 1906, pp. 21-72. 



Matthew, W. ID. A Lower Miocene Fauna from South Dakota. 

 Bull. Am. Mus. Nat. Hist., Vol. 23, 1907, pp. 169-219. 



