58 CARNIVORA order hi 



Claenodon Scott [Miodaenus Cope in part). Upper molars resembling 

 preceding form, P'^ with strongly developed inner tubercle. Extremities like 

 those of bears, but astragalus with long neck. Torrejon beds. C. ferox, 

 C. corrugafus Cope. 



Anacodon Cope. Tubercles obscure. A. ursidens Cope, Wasatch beds. 



Family 6. Miacidae Cope. 



P* and M-^ developed as carnassials. Upper molars trituheradar, lower molars 

 tuherculo-sedorial with high trigonid and much reduced talonid. Extremities 

 pentadactyl. 



The Miacidae are small to moderate-sized carnivores, resembling in 

 dentition partly the Viverridae, and the primitive Canidae and Ursidae, being 

 doubtless the common ancestor. They may be distinguished from the latter 

 by the absence of a bony tympanic bulla, the free scaphoid, centrale, and 

 lunar bones, and principally by the presence of a third though small 

 trochanter in the femur. The brain is much more developed than in 

 other creodonts. As the skeletal structure becomes better known, it may be 

 possible to assign here a number of European forms, such as those provisionally 

 regarded as Eocene species of Viverra and Amphicyon. 



Subfamily 1. Viverravinae Matthew. 



•| if. Inner cusp of P* and posterior cusp of P^ large. Toes compactly set, 

 digitigrade. Humerus with loiv deltoid crest, and prominent 

 greater tuberosity. Femur with prominent elongated third 

 trochanter. Astragalus with narrow head, and somewhat 

 grooved trochlea. Fibula articulating with calcaneum. Cranium 

 somewhat elongated. 



Viverravus Marsh. Teeth compressed. Upper molars 

 lacking median tubercles, 3P with small hypocone. il/j^ 

 with short pitted talonid. Bridger beds. V. dawhinsianus 

 Cope ; V. minutus Wortman. These are probably 

 ^., . ,. ■, ', . present also in Upper Eocene of Quercy, France. Re- 



Didymiclis haydvntamts r i ■ , t-- t -r. i ■ 



Cope. Puerco of Lower ported from Laudenien of Erquehnnes, helgium. 

 fmvHor' aspect of^'^iert Didymictis Cope (Fig. 85). Dentition massive. M^ 



"^^Vow^m^^^'^Ti^^^v lacking hypocone. M^ with pitted talonid. Torrejon 

 Cope.) and Fort Union beds. D. haydenianus, D. protenus 



Cope. Wasatch and Wind River beds. 



Subfamily 2. Miacinae Matthew. 



^ M. Inner cusps of P'^ small or wanting. Extremities ptlantigrade, toes 

 spreading. Humerus with prominent deltoid crest, but small greater tuberosity. 

 Femur with low ami extended third trochanter. Astragalus with broadened head 

 and flattened trochlea. Fibula not articulating with calcaneum,. Cranium of 

 moderate size. 



Miacis and Uiniacyon attain the size of dogs and raccoons respectively. 



