Temminck, 1841
Black-bearded tomb bat
External characters (Table 19)
This species is comparable in size to T. longimanus but with a longer forearm (64.6 mm; 60.0-68.0 mm) but relatively shorter third metacarpal, averaging 89.2% (84.9-92.7%) of forearm length; in T. longimanus the third metacarpal is normally about equal to or exceeds forearm length. Also, unlike T. longimanus (Fig. 43), there is no gular sac in either sex and the chin and throat are always hairy. Males, at the age of about six months, grow a characteristic beard (Tme1) which is variable in colour but usually has a jet black central part, surrounded by ginger hairs and in some instances paler hairs posteriorly. During the period of rut small glands under the chin of the male produce a thick secretion which runs over the beard (Brosset, 1962a). The pelage colour is variable ranging from russet brown to almost black on the back (Tme8); the belly is usually paler (Tme3). The hair bases are pale and may give the pelage a mottled appearance (Tme2), especially in females. In contrast to T. longimanus (Tme4), the wings are attached to the tibiae (Tlo6), not the ankle and the fur extends to only one third the length of the humerus and femur on the upper body, as opposed to one half in T. longimanus . The tail is thickened towards the tip and somewhat laterally compressed (Tlo1). The radio-metacarpal pouch of each wing is well developed (Tme9). The ears are usually larger than those of T. longimanus (Tlo3).
Karyology
2N= 42, FN= 64 based on six males collected from Aurangabad in Maharashtra. There are 9 pairs of metacentric chromosomes; three pairs of submetacentrics and eight pairs of acrocentrics; the X chromosome is a medium sized metacentric and the Y an acrocentric (Ray-Chaudhuri et al., 1971).
Cranial characters
The skull, with an average condylo-canine length of 20.2 mm (19.5-21.5 mm), can usually be distinguished from that of T. perforatus (Fig. 48) by its larger size and distinctly broader braincase. The cranial morphology is closely similar to that of T. longimanus (Tlo8) and the skulls of the two species cannot be distinguished with certainty, although in general the basisphenoid pits of T. melanopogon are longer and broader.
Dentition
The maxillary toothrow (C-M3) with an average length of 9.0 mm (8.6-9.2 mm) and the mandibular toothrow are the longest of the three small species of Taphozous found in the region. The structure of the teeth is essentially similar to that of T. longimanus and T. perforatus (Fig. 50).
Variation
Specimens from throughout the Indian subcontinent are referred to the nominate race T. m. melanopogon . The taxon bicolor is not considered distinct even at the subspecific level. There is considerable individual variation in size and colour.