ey to the 

 nivores 



by Richard H. Tedford 



At dawn in Tanzania's Serengeti Na- 

 tional Park, a lioness creeps close to the 

 ground, stalking a young wildebeest that 

 has drifted from the herd. She must narrow 

 the distance to her prey as much as pos- 

 sible because her powerfully built body 

 cannot sustain a lengthy run. Her eyes 

 fixed on the wildebeest's neck, she judges 

 the distance to be proper and lunges at full 

 speed. The wildebeest realizes something 

 is wrong only a fraction of a second before 

 it feels the crash of the lioness's body and 

 the suffocating grasp of her jaws upon its 

 throat. The force of the attack topples the 

 wildebeest; the lioness holds on until the 

 thrashing ends. 



A mile or so away, a pack of hunting 

 dogs have harassed a herd of zebras for 

 many minutes, looking for prey. Their 

 teamwork has isolated an old mare, and 

 they close in for the kill. Although small 

 and slender, the dogs have broad muzzles 

 and powerful jaws. They nip and bite the 

 zebra's flanks and hind legs. A dog seizes 

 the soft muzzle with its large incisors and 



holds on with a viselike grip; the rest of the 

 pack begins to eat the immobihzed zebra 

 as it stands. 



Across the plain, a jackal is hunting 

 springhase, rabbitlike rodents whose agile 

 jumping poses a challenge to any predator. 

 The jackal pirouettes and leaps as it fol- 

 lows the evasive action, finally securing its 

 prey using the quick snapping action of its 

 long jaws. 



These killing techniques are examples 

 of the special behavior that carnivorous 

 mammals painstakingly learn. Killing is a 

 function of the front part of their mouths. 

 Nipping incisors, piercing canines, and 

 tight-gripping, bladelike premolars are 

 strategically set in skulls of different 

 length and width to take advantage of the 

 muscular force of the bite. Yet the teeth 

 that lions, dogs, and jackals use for killing 

 are not radically different from those 

 found in many noncamivorous mammals. 

 Farther back in their mouths lie some spe- 

 cial teetii known as the camassials. These 

 are the haUmark of the true carnivores, or 



camivorans — members of a great order of 

 placental mammals, the Camivora. Useful 

 for shearing meat, these teeth are funda- 

 mental to feeding as opposed to killing. 



In an adult animal, the camassials con- 

 sist of the upper last premolar and lower 

 first molar on both sides of tiie jaws. These 

 bladelike teeth, which oppose each other, 

 can scissor through flesh and slice off 

 morsels of meat. Each camassial has two 

 narrow cusps, separated by a notch that 

 holds the piece of meat in place as it is 

 being cut. Even newborn carnivores are 

 equipped with camassiallike baby teeth 

 that function this way. Young carnivores 

 are introduced to meat before they are 

 weaned, and these baby camassials are 

 important to their nutrition and survival. 

 The baby camassials, however, consist of 

 the third upper premolar and last lower 

 premolar (the permanent premolars that 

 eventiially replace them are much simpler 

 in form). 



The camassials in all tme carnivores, 

 large and small, always fall about halfway 

 between the jaw joint near the ear and the 

 front end of the jaw. This corresponds with 

 the position of maximum bite force deliv- 

 ered by the great temporalis muscles, 

 which originate on the side of the skuU 

 and, in large camivores, often extend from 

 the flanks of a prominent crest of bone, the 

 sagittal crest, at the top of the skull. 



Although the muscles on both sides of 

 the head operate together, a carnivore 

 chews off pieces of meat using the camas- 

 sials on only one side at a time. Asmte 



74 Natural History 4/94 



