268 LAND MAMMALS IN THE WESTERN HEMISPHERE 



though they were not very numerous. Though not at all 

 related to that group, the ftillodonts looked like huge rodents, 

 with their chisel-like incisor teeth. There was a remarkable 

 assemblage of Insectivora, more numerous and varied than in 

 any subsequent formation, no less than six families being known. 

 One of these somewhat doubtfully represented the moles and 

 two others modern Asiatic groups. The very unexpected 

 discovery of an armadillo in the Bridger has been reported, 

 but the propriety of referring this animal to the armadillos, 

 or even to the edentates, has not yet been proved, and it would 

 therefore be premature to discuss its significance. The only 

 marsupials were opossums. 



So far as our information extends, there were no true Car- 

 nivora in the Bridger, all the beasts of prey of the time belonging 

 to the archaic fCreodonta, which then reached their maximum 

 development in numbers and diversity. One family (fOxy- 

 aenidse) included large and powerful flesh-eaters, with cat-like 

 dentition and short, rounded, lion-like heads, long bodies and 

 tails and short, heavy limbs, giving them the proportions 

 of otters. Another (the jHysenodontidse) comprised small, 

 long-headed, fox-like and weasel-like animals, which doubtless 

 preyed upon small mammals and birds. A third family 

 (fMesonychidse) was made up of moderate-sized, long-jawed 

 creatures, which must have resembled, rather remotely, short- 

 legged and long-tailed wolves and hyenas. Their habits and 

 mode of life are somewhat problematical, for their grinding 

 teeth were blunt, not adapted to the shearing of flesh, and their 

 claws were broad, almost hoof-like. Such creatures could 

 hardly have subsisted by the pursuit of living prey and were 

 probably carrion-feeders and more or less omnivorous. The 

 jMiacidse, a family which connected the fcreodonts and true 

 carnivores and might almost equally well be placed in either 

 group, were externally much like the small thya?nodonts, but 

 were more efficiently equipped for the capture and devouring 

 of prey. 



