SOUTH DAKOTA SCHOOL OF MINES 77 



or aquatic. They have a simple stomach, a well developed 

 brain, toes provided usually with long, sharp claws, and 

 generally they have a body capable of much agility in the 

 capture of prey. They walk either upon the entire sole of 

 the foot or upon the under surface of the toes but never 

 upon the tips of the toes as do the Ungulata. The carni- 

 vorous structure is common to all of the class but the 

 carnivorous habit, though general is not universal. Living 

 representatives vary in size from the little active ermine to 

 the powerful grizzly Jbear. The Kodents include a group of 

 small to moderately large animals the most prominent and 

 universal character of which is their dentition. Canine 

 teeth are absent. The deeply set incisors, separated by a 

 considerable vacant interval from the molars, are long and 

 flat edged and are of paramount importance. Since they 

 lengthen by persistent growth they serve admirably for 

 vigorous chisel-like cutting of hard materials, hence the 

 name "gnawers." The animals are usually plantigrade, 

 often burrowing, not infrequently arboreal, and occasionally 

 acquatic. They are today represented by the squirrels, 

 prairie dogs, rabbits, rats, mice, beavers, porcupines, and a 

 host of others. The Ungulates (Herbivores) are plant- 

 feeding animals with hoofs rather than claws or nails, and 

 with limbs perfected for running and not for climbing and 

 grasping. Viewed from the point of usefulness to man they 

 are the most important of all animals in that they furnish 

 him with food, clothing and working assistance. 



CARNIVORES 



The Carnivora may be conveniently divided into three 

 sub-divisions (sub-orders), namely, the Creodonta or primi- 

 tive carnivores, the Fissipedia or true carnivores, and the 

 Pinnipedia or aquatic carnivores. Of these the Creodonts 

 are found only in the fossil state ; the Fissipedes include our 

 common carnivorous animals such as the Canidae (dogs or 

 dog-like creatures) and the Felidae (cat family), and are 

 both fossil and living. They are found in large numbers 

 among the fossils of the badlands. The Pinnipedes include 

 the aberrant animals, the seals and walruses. The Creodonts 

 are represented in the White River badlands by but one 

 family, the Hyaenodonts. The Pinnipedes are not found 

 there at all. 



