FUNCTIONAL DISCRIMINATION IN THE MASTICATORY APPARATUS OF JUVENILE AND ADULT COUGARS (PUMA CONCOLOR) AND SPOTTED HYENAS (CROCUTA-CROCUTA)

Functional analyses of the teeth and jaws of juvenile and adult cougar s (Puma concolor) and spotted hyenas (Crocuta crocuta) indicate severa l key differences and similarities in the design of thr masticatory ap paratus between species and age groups. Data from adults indicate pref erential use of the precarnassial premolars in C. crocuta for durophag y (feeding on hard foods), and in P. concolor are suggestive of the ne ed to use their carnassials during durophagy. In juveniles, powerful b iting is limited to the caudalmost corpus (i.e., excluding the deciduo us precarnassial premolars in P. concolor and many specimens of C. cro cuta); however, dental replacement patterns determine how many and whi ch teeth are available for use in this function. The most limiting sce nario is one in which dP(4) has been shed but eruption of P-4 is incom plete, leaving only dP(3) and the minute M(1) to deliver strong bite f orces. This condition occurs well after weaning in P, concolor but coi ncides more closely with the age of weaning in C. crocuta. It is durin g this period of masticatory compromise that juvenile C. crocuta must begin to join adult dan members at carcasses and thus must be able to feed aggressively with a masticatory apparatus that is poorly equipped to do so.