Trinidad small mammals Marsupials 1. size small Marmosa (2 sp.) 1' size large 2. feet webbed 2'. feet normal chronectes minimus Caluromys phalander Didelphis 3. wooly, more than 1/3 tail haired 3'. not wooly, less than 1/3 tail haired Rodents squirrel external cheek pouches Sciurus granatensis Heteromys anomalus non cicetids 1. hind foot tridactyl, cursorial 1'. hind foot normal Dasyproata agouti Echimy's armatus Proechimys guyanensis 2. spiny? 2'. not spiny? Cricetids 1. deep labial ridges m' m² 2. weak teeth, ridges may be lost, small microtus-like Akodon (2 sp) 2'. teeth not weak, larger 3. Palate not reaching posterior part of tooth row Rhipidomys couesi 3'. Palate extending beyond tooth row 4 flat crowned teeth Nectomys squamipes Onychomys (4 sp.) Zygodontomys brevicauda 4'. not flatcrowned 1'. labial ridge not pronounced, cusps opposite