PILOSA

PILOSA

1. characteristics

   • sloths
     • no incisors or canines 
     • cheekteeth CYLINDRICAL; core of dentine but NO enamel 
     • anterior upper premolar is CANINIFORM, separated from other cheekteeth by diastema 
     • almost entirely ARBOREAL and FOLIVOROUS; descend to ground only to defecate every 4-7 days 
     • long-lived (>30 YEARS)
     • HETEROTHERMIC (24-33 degrees C) limits distribution 
     • several compartments to stomach; microfauna aid digestion, fermentation of leaves 
   • anteaters
     • FULLY EDENTATE 
     • long tapered skulls with elongated rostrum, small mouth, long (600mm) skinny (13mm)
     • tongue anchored to STERNUM, viscous secretion, barb-like spines pointing posteriorly for ants 
     • long, sharp, powerful claws, middle enlarged 
     • total body and tail length = 2m up to 40kg (silky anteater is smaller - 400mm, 230g)
     • mostly TERRESTRIAL, but silky is TOTALLY ARBOREAL 
     • TAMANDUAS either diurnal OR nocturnal 

2. fossil history

   • date back to PALEOCENE (54-65 mya)
   • many extinct sloths much LARGER than current ones
   • giant ground sloth weighed >2700kg (6000lbs), could reach up approximately 6 meters into trees  
   • would have been present in SW U.S. up to about 11,000 mya

3. economics and conservation

   • arboreal sloths reduced in numbers due to tropical forest loss
   • giant anteater ENDANGERED