Two new species of of Bunomys are described, B. karokophilus and B. torajae, both from the west-central mountain region of central Sulawesi. The descriptions are presented within the context of a systematic review of Bunomys in which are provided characteristics of the genus and species (external form, secondary sexual traits, spermatozoa, stomach morphology, skull, dentition, chromosomes); diagnoses, geographic and elevational distributions; sympatric, syntopic, and parapatric distributional relationships; morphological, distributional, and in some cases ecological comparisons among the species; natural histories for certain species derived from field observations; parasites; allocation of generic and specific synonyms; and documentation of subfossils for two of the species.
Eight species are recognized; all are nocturnal, terrestrial, and endemic to the island of Sulawesi. Bunomys chrysocomus has been collected from most regions of the island and inhabits both lowland tropical evergreen and montane rain forests (elevational range = 250–2200 m). Bunomys coelestis is endemic to montane forests on Gunung Lompobatang, the high volcano at the southern end of the southwestern peninsula (1829–2500 m). Bunomys prolatus has been reported only from mountain forest on Gunung Tambusisi at the western end of the eastern peninsula (1829 m). Bunomys torajae, n. sp., is described from a small sample collected in montane forest on Gunung Gandangdewata at the southern end of the west-central mountain block (2500–2600 m). Bunomys fratrorum is currently documented only from the northeastern area of the northern peninsula where it occupies habitats in lowland tropical evergreen and montane rain forests (coastal plain to 1982 m). Bunomys andrewsi has been collected primarily in lowland tropical evergreen rain forests in the core of Sulawesi and on the eastern, southeastern, and southwestern peninsula (coastal plain to 1600 m). Bunomys penitus is strictly montane and recorded only from the west-central mountain block and Pegunungan Mekongga on the southeastern peninsula (1285–2287 m). Bunomys karokophilus, n. sp., is currently known only from lowland tropical evergreen rain forest in the northern portion of the west-central mountain block (823–1150 m).
Analyses of morphometric traits (cranial and dental measurements) results in a phenetic relationship among the species in which B. chrysocomus, B. coelestis, B. prolatus, and B. torajae, n. sp., form one group characterized by small physical size and small molars, and B. fratrorum, B. andrewsi, B. penitus, and B. karokophilus another group in which larger physical size and heavier molars are the phenetic definers. Whether or not the integrity of this phenetic pattern will withstand testing by analyses of DNA sequences, it remains a convenient arrangement in which to present and define the eight species.
The morphological, elevational, and ecological relationships among the four species of Bunomys (B. chrysocomus, B. andrewsi, B. penitus, and B. karokophilus, n. sp.) collected along my transect area in the northern portion of the west-central mountain block (presently known as Lore Lindu National Park) and comparison between them and the elevational distributions of the other murids encountered along the transect are described.
Finally, a brief introduction to the species of murid rodents that have been recorded from mainland Sulawesi and nearby islands is provided, which defines the murine faunal context for the species of Bunomys.
The treatment of Bunomys offered here focuses on definitions of the species as outlined by phenetic traits, elevational and geographic distributions, and the natural hi