796.

Seram Island Mountain Rat

Nesoromys ceramicus

French: Rat de Céram / German: Seram-Dschungelratte / Spanish: Rata de montana de Seram

Other common names: Seram Rat

Taxonomy. Stenomys ceramicus Thomas, 1920,

“Mt. Manusela [Pulau Seram, Maluku (Moluccas), Indonesia]. 6000’ [= 1830 m].”

Nesoromys ceramicus has been included under Stenomys by some authors. The phylogenetic position of this species is currently unknown and genetic studies are needed. Monotypic.

Distribution. Restricted to Mt Manusela, Seram I, Moluccas, Indonesia; it might occur in another Sm on Seram I.

Descriptive notes. Head-body 118-135 mm, tail 126-140 mm, ear 17-18 mm, hindfoot 28-30 mm; weight 66-5 g. The Seram Island Mountain Rat is a small rat with soft pelage. Dorsal pelage is a dark olive-brown coloration with fine speckling. Ventral pelage is a slightly ligher olive brown with no demarcation from the dorsal pelage and with dull drabby tipped hairs. Ears are short and blackish. Tail is comparatively long (104-107% of head-body length), nearly naked, and dark brown. Hindfeet are proportionately long and andsomewhat broad; both hindand forefeet are dark brown. Palatal bridge extends well after M°—the most distinctive feature; small postorbital ridge; slightly developed temporal ridge; wide zygomatic notch. Rostrum is long and narrow; and lateral space between zygomatic root and both maxillary and sphenoid bones. Laterally, top ofskull is curved between nasal and occipital; zygomatic arch is laterally at level of upper molar row; squamosal root of zygomatic arch is close to tympanic bulla; posterior palatine foramina is at or after M?; jugular process is moderately developed; in palatal view, squamosal root of zygomatic arch position does not overlap tympanic bulla; in palatal view, zygomatic root of zygomatic arch overlaps at level of the M';eustachian tube is short and wide; post-glenoid vacuity is fused with middle lacerate foramen; basisphenoid seems to be suspended in spheno-palatine vacuity; posteriorly, incisive foramina does not reach M' and is very short; angular process does not extend after posterior part of articular condyle and is not well-developed; incisors are orange, with notch on upper orthodont incisor of one specimen; incisor blade is narrow, with inferiorsize to its longest basal width; cusp t7 is absent on M!, M?, and M?; postererocone is present on M' but poorly developed; cusp t3 is present on M? but is absent on M?tl is present on M'; cusp tl of M' is at same level or just in front of t3, cusp tl + t2 + t3 forming a U-shaped lamina; there is no antero-labial cusplet on m; anteroand postero-labial cusplets are present on m; anteroand postero-labial cusplets are present on m, of the holotype,but postero-Jil cusplet is not visible on other specimens; and m, fas antero-labial cusplet, but postero-labial cusplet is absent.

Habitat. Highland and primary montane and mossy forests at elevations of 1500 2000 m.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. The Seram Island Mountain Rat is nocturnal and likely terrestrial.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Endangered on The IUCN Red List. The Seram Island Mountain Rat does not face many threats, as it isfound at high altitudes, but there is continued habitat degradation in lower altitudes from logging that may affect the quality of the habitat where this species lives. Competition with introduced Roof Rats ( R. rattus) may be a threat. The species is known from few specimens and further research is needed to understand the taxonomy, ecology, and possible threats to this species.

Bibliography. Aplin, Brown et al. (2003), Corbet & Hill (1992), Dickman & Wright (2016), Ellerman (1941, 1949), Flannery (1995a), Helgen (2003), Laurie & Hill (1954), Misonne (1969), Musser & Holden (1991), Rimmler (1938), Simpson (1945), Thomas (1920c).