Chilomys instans (Thomas)

VOSS, ROBERT S., 2003, A New Species of Thomasomys (Rodentia: Muridae) from Eastern Ecuador, with Remarks on Mammalian Diversity and Biogeography in the Cordillera Oriental, American Museum Novitates 3421, pp. 1-48 : 23

Chilomys instans (Thomas)

SPECIMENS COLLECTED: 7.5 km (by road) W Papallacta, 12,000 ft (UMMZ 155795); 6.2 km (by road) W Papallacta, 11,700 ft (UMMZ 155619, 155620).

OTHER MATERIAL: None.

TAXONOMY: The morphologically distinctive genus Chilomys Thomas (1897a) is currently thought to contain only a single valid species, C. instans ( Thomas, 1895b) ; another nominal taxon, fumeus Osgood (1912) is either a subspecies or synonym according to Cabrera (1961) and Musser and Carleton (1993). The Papallacta specimens closely resemble the holotype of instans (BMNH 95.10.14.1, from Bogota´) in qualitative characters, but they have slightly broader interorbits and shorter molar rows. A revision of this long­neglected northern­Andean endemic genus is necessary in order to evaluate the taxonomic significance of character variation among these and other specimens from Ecuador, Colombia, and western Venezuela.

FIELD OBSERVATIONS: The three specimens of Chilomys instans that I collected near Papallacta in 1980 were trapped at elevations ranging from 3600 to 3690 m. One specimen was trapped on a mossy log over a stream in Subalpine Rain Forest, another on the ground in a narrow runway beneath mossy shrubs in the same habitat, and the third in a mossy tunnel beneath bunch grass in the páramo/ forest ecotone .