RattusDivision. A Sulawesi endemic. Formerly included in Rattus by Ellerman (1949a), and in subgenus Bullimus of Rattus by Misonne (1969), but considered a distinct genus by Musser (1981c, 1984, 1987) and Musser and Newcomb (1983); albumin immunology nestles Taeromys in a Rattus clade (also containing Sundamys, Bunomys, Komodomys, Stenomys, Bullimus, Bandicota, Nesokia, Paruromys, Papagomys, and Berylmys; Watts and Baverstock, 1994b, 1995b, 1996). Partially reviewed and contrasted with Sundaic Sundamys by Musser and Newcomb (1983). Marked interspecific contrasts in spermatozoal morphology evident among species and reflected by differences in cranial and dental traits (Breed and Musser, 1991). Sody (1941:260) proposed nine new genera, each diagnosed by mammary formula. Among these were Taeromys and Arcuomys, which Corbet and Hill (1992:287) regarded as doubtfully valid ". . . since they were based solely upon mammary formulae shared with other genera proposed on the same page." But Sody diagnosed his genera in a comparative context, listing the mammary formulae for all the new genera, and the names seem to satisfy the conditions of Article 13 in the fourth edition of the International Code of Zoological Nomenclature (International Commission on Zoological Nomenclature, 1999). Corbet and Hill (1992:287) also noted that Arcuomys had line priority over Taeromys, but the latter can be viewed as having priority following Musser (1981c:137) as "first reviser." Because Sody’s diagnosis only highlighted mammary formula, we provide the following emended diagnosis for Taeromys: A genus of Murinae (as that subfamily was defined by Carleton and Musser, 1984) characterized by 1) large body size; 2) short, soft, and dense fur composed of thin and pliable hairs; 3) short guard hairs barely extending beyond over overfur layer of dorsal coat; 4) gray or dark grayish brown upperparts in most specimens, reddish brown in a few (some examples of T. celebensis and all specimens of T. punicans); 5) long and slender hind feet with six fleshy plantar pads, which includes a hypothenar; 6) length of tail shorter to slightly longer than length of head and body in all species except T. celebensis (much longer), and bicolored (basal one-third to one-half brown or blackish brown, distal segment white) in all species except T. punicans (monocolored); 7) smooth, glistening tail surfaces due to non-overlapping rings of thin scales and very short, fine scale hairs; 8) either three pairs of teats (one postaxillary pair and two inguinal pairs; most samples) or two inguinal pairs only; 9) slim and long rostrum (except T. celebensis); 10) wide zygomatic plate (but its anterior margin not covering nasolacrimal capsule) and deep zygomatic notch (except T. celebensis); 11) low and inconspicuous postorbital ridges, barely evident temporal ridges; 12) short incisive foramina, their posterior margins ending anterior to molar rows in T. celebensis, T. callitrichus, and T. arcuatus, but slightly projecting between the rows in T. taerae and T. hamatus; 13) posterior margin of bony palate either even with end of third molars or extending slightly beyond them; 14) sphenopalatine vacuities short and narrow; 15) large stapedial foramen and prominent groove in pterygoid plate for infraorbital branch of stapedial artery (which reflects the primitive murine state of cephalic arterial supply); 16) no alisphenoid strut; 17) small auditory bulla relative to cranium (except T. celebensis); 18) configuration of upper incisors mainly orthodont, slightly opisthodont in some species; 19) each first upper molar anchored by five roots, the second molar by four, and the third by three, each first lower molar with four roots, the second and third with three roots; 20) large molars relative to size of cranium and mandible, crowns slightly hypsodont; 21) rows of cusps on upper molars more laminar than cuspidate, anterolabial cusps (t3) on first and second upper molars reduced in size or absent, posterior cingulum usually absent from each first and second upper molar, no cusp t7, and no anterocentral cusp on each first lower molar; 22) entepicondylar foramen present; 23) stomach unilocular-hemiglandular; 24) 2n = 42, FN = 60 for an undescribed species, 2n = 39, FN = 50 for males of T. celebensis and 2n = 39 or 40, FN = 49 or 50 for females (X1X1X2X2 female/XsX2Y male system); Musser, ms).

Most species of Taeromys are difficult to trap (Musser’s experience in the forest), which is reflected by their meager representation in museum collections. Current patterns of geographic distributions and character variation revealed by morphometric analyses (Musser, ms) requires testing by larger samples and exposure to analyses of other data sets, both morphological and molecular. An additional species not listed here is found in montane forest formations dominated by species of oak (Lithocarpus) and chestnut (Castanea) in C Sulawesi, is allied to T. arcuatus, and will be described by Musser (ms).