Chironax melanocephalus

Descriptive notes. Head-body 55 - 72 mm (tailless), ear 11 - 15 mm, hindfoot 9 - 3 - 10 - 6 mm, forearm 44 - 48 mm; weight 16 - 20 g. Sumatran specimens appear to have two morphs; one is slightly larger and more similar to the Bornean subspecies dyasae, which might represent an undescribed species of Chironax. Head and moderately elongated muzzle are blackish and almost hairless, nostrils are shortly tubular and divergent, philtrum is divided into two parallel grooves, and lower lip pads are large. Skin around eyes is naked, eyes are large, and iris is dark brown. Ears are short, rounded, and almost black. Head pelage is short, dense, and very dark blackish brown, continuing on nape; dorsum is a lighter grayish, with longer woollier hairs (lighter or “ linoleum brown ” in dyasae). Uropatagium is undeveloped at center and densely covered dorsally with soft brown hairs, calcar is small, and foot claws are whitish. Throat is sparsely haired; sides of neck and shoulders have tufts of yellowish to intensely orange hairs, turning creamy in chest and more grayish and woollier on venter to genitals. Underside of uropatagium is densely haired. Wing membranes are black from sides of body and attach on second toe, and index claw is present. Skull is small and delicate, with no basicranial deflection; rostrum is gracile, gently sloping into forehead; premaxillae are fused; orbit is large; zygomatic root is only slightly above upper alveolar line; zygomais very thin and arched posteriorly; and braincase is rounded and globose. Dorsally, rostrum is relatively wide, paranasal recesses are inflated, surpassing posteriorly root of small, thin postorbital processes; postorbital constriction is not marked; braincase is oval, with barely noticeable sagittal crest; and nuchal crest is obvious. Ventrally, palate is flat, tooth rows are gently diverging, post-dental palate is long and convergent, end of post-dental palate 1 s flat, sphenoid crest is present, and ectotympanic is small and wide anteriorly and internally edged by adpressed and wide entotympanic. Mandible is thin, coronoid is long and sloping, condyle is level with lower alveolar line, and angle is rounded and distinct. Dental formula for all species of Chironaxis 12 / 2, C 1 / 1, P 3 / 3, M 1 / 2 (x 2) = 30. Upper dentition has two pairs of crowded, relatively short incisors; C' is thin, short, and slightly decurved; P' is a spicule; next premolar (P °) is large and triangular, with distinct additional anteroexternal cusp; posterior cheekteeth decrease in size, and all cheekteeth are rectangular in outline. Lower dentition has two pairs of small incisors; C, 1 s small, short, and barely curved; P |, has pointed crown; and posterior cheekteeth are anteriorly almost as high as C ,, decreasing in size and all with rectangular outline, except peg-like M ..

Sumber: Pteropodidae