A NEW SPECIES OF LOXODONTOMYS, ANOTHER PHYLLOTINE MAMMAL FROM THE ANDES OF CENTRAL CHILE

A new phyllotine species, related to Loxodontomys micropus 2n= 34 and NF= 36 (Rodentia, Muridae, Sigmodontinae) is described for the high mo untains of Central Chile, from Santiago to Chillan. Three specimens fr om El Morado y Las Melosas, Region Metropolitana, exhibited 2n= 32 y N F= 34, all chromosomes telocentric excepting the small metacentric pai r 15; their G bands were identical to those obtained from three San Fe rnando specimens, as well as their skull and body morphology with resp ect to that observed in other three populations from Central Chile. Th ese two genomes are cytogenetic and biogeographically separated, and t hat of the new species results intermediate in 2n and NOR numbers betw een L. micropus from Southern Chile and Argentina and the northern spe cies of NF= 32 Auliscomys. The new species differed by the larger dors al-ventral contrast in the skin, bicoloured tail, opistodont incisives with a short oclusal figure, although they shared most of 70 state ch aracters. The cladistic and morphometric analysis were able to provide a good separation of the two Loxodontomys species from the rest of au stral and Altiplanic phyllotine species.