Hardwicke, 1825
Long-winged Tomb bat
External characters (Table 18)
This is a small species of Taphozous with a short forearm (59.2mm; 55.6-62.0 mm). However, the third metacarpal is relatively long, usually equal to or exceeding the length of the forearm; in T. melanopogon and T. perforatus it is shorter, about 90% of forearm length. The muzzle is simple; the nostrils open forwards and have a narrow groove between them (Tlo3). The sides of the face are almost naked and are dark brown in colour. The ears are relatively short and narrow; their bases are covered with hairs posteriorly and their tips are bluntly rounded off; the anterior and posterior margins are straight. The antitragal lobe of each ear is elevated above the inferior margin of the pinna and the tragus is well developed and club-shaped. The chin is essentially naked in both sexes; males have a large gular sac (Fig. 43); in females there is a rudimentary fold of skin. According to Sinha, 1986a, there is also a pectoral gland in the male which oozes a yellow creamy secretion in the breeding season. The pelage is short and soft. Its colour varies from cinnamon brown to reddish brown to black; the darker individuals are usually females. Both sexes may be speckled with paler patches on the dorsal surface; the belly tends to be lighter brown than the back. The hair bases are usually paler than the tips. The fur on the dorsal aspect of the body extends onto the wing membranes for about half the length of each humerus and femur, with the remainder of the wing quite naked; in T. melanopogon , the comparable figure is about one third. The fur also extends on to the upper surface of the interfemoral membrane. The membranes are dark brown throughout. In contrast to both T. melanopogon (Tlo6) and T. perforatus (Tlo5), the wings are attached to the ankles (Tlo4) and not to the tibiae; the radio-metacarpal pouch of each wing is only moderately developed. Like other species of Taphozous , this bat has a strong and unpleasant smell.
Karyology
2N= 42, FN= 64 based on males and females from Uttar Pradesh; there are eight pairs of metacentric, four pairs of submetacentric and eight pairs of acrocentric autosomes; the X chromosome is a medium sized metacentric and the Y chromosome a minute acrocentric (Ray-Chaudhuri et al., 1971).
Cranial characters
The skull, with an average condylo-canine length of 20.0 mm (19.2-21.6 mm) is closely similar in size and morphology to that of T. melanopogon . The premaxillae are separated from each other by a gap and are not fused to the maxillae. They are narrow and slender in their lower parts and widened above. The rostrum is broad in comparison to T. perforatus and there is a well developed concavity medially. The postorbital processes are long and slender; their anterior margins are concave, their posterior margins convex. The braincase is broader posteriorly than that of T. perforatus , comparable to or smaller than that of T. melanopogon . The sagittal crest is scarcely evident except as a very slight ridge on an otherwise smooth braincase. The lambdoid crests are present but not well developed and the occiput is rounded, not pointed as in T. nudiventris . In side view, the braincase is distinctly elevated above the rostrum, especially posteriorly. The zygomatic arches are not greatly flared laterally; their outer borders are almost straight. The palate is short, slightly rounded and convergent anteriorly. The anterior border of the mesopterygoid space is V-shaped, in T. perforatus it is U-shaped. The hamular processes are long, delicate and outwardly slanting. The basisphenoid pits are deep with a well defined median septum; their length (antero-posterior diameter) is about 3.8 mm, this exceeds that of T. perforatus which ranges from about 2.6-3.2 mm. The mandible is without special features and is closely similar to that of T. perforatus (Fig. 48).
Dentition
- Upper toothrow length (C-M3) averages 8.9 mm (8.7-9.2 mm). The upper incisor (I2) is minute or sometimes absent; when present, it is a simple conical tooth. The canine is powerful, with antero-medial and postero-medial cingular cusps and a large sloping heel. The first premolar (PM2) is small; it has a single cusp and is situated in the toothrow. The second premolar (PM4) is powerful; it attains three-quarters the height of the canine; the cingulum is well developed medially. M1 and M2 are approximately equal in crown area, with M1 being slightly narrower transversely but with a greater antero-posterior diameter. The paracone is significantly less developed than the metacone in M1, whilst in M2, the paracone is about equal in size. M3 is reduced; it is comprised of a parastyle, paracone, protocone and two commissures.
- The first (i1) and second (i2) lower incisors are trilobate and crowded together with i2 partially situated behind i1. The lower canine possesses an anterior cingular cusp, the tip of which is above i2; there is a weak posterior cusp. The first lower premolar (pm2) overlaps the base of the canine and is about equal in crown area with the second (pm4). m2 exceeds m1 in size whilst the talonid of m3 is greatly reduced.
Variation
Specimens from throughout the subcontinent are referred to the nominate form T. l. longimanus . The taxa fulvidus , brevicaudus and cantori described on account of minor differences in size, pelage colour and structure of the ear and tail are not now considered distinct even at a subspecific level.