E. Geoffroy, 1810
Greater False Vampire
External characters (Table 24)
This is a robust species with an average forearm length of 66.4 mm (56.0-71.5 mm); this significantly exceeds that of Megaderma spasma . The head is characterised by its large, oval ears which have a fringe of white hairs on their anterior margins (BW14). The ears are joined medially for between one third and half their length (Mly1). Each ear has a bifid tragus, the posterior process of which is taller. The face is hairy on the forehead and upper cheeks. However, the snout is essentially naked; it is flesh coloured but with some well defined papillae. The lower jaw projects beyond the upper. The noseleaf is erect, straight-sided and some 10 mm in height; it has a longitudinal ridge and a simple rounded horizontal base (Rmi5); in M. spasma , the noseleaf is short (6.5 mm in height) with convex sides and a distinctly heart-shaped base (Msp1). The pelage is fine, soft and moderately long. It extends on to the forearms for half their length dorsally. The upper surface of the body is a uniform mouse grey faintly washed with brown. The ventral surface is paler, with the hair tips on the throat and belly white; the hair bases are grey (Mly4). Whitish hairs extend around the posterior ear bases and on to the wing membranes from the axillae to the groin. Juveniles have a comparatively dark pelage. The membranes and ears are greyish black and semi-translucent. The wings are broad (Mly3).
Cranial characters
The skull (BW13) has an average condylo-canine length of 25.4 mm (24.5-27.8 mm). The premaxillae are essentially absent (represented by tiny thread-like bones only) and the nasals are greatly reduced. In consequence, the upper canines project forwards to form the most anterior part of the cranium (Fig. 56). Although the rostrum is relatively small in relation to the large ovate braincase, powerful supraorbital ridges are present; these overhang the orbits and terminate in blunt postorbital processes. The zygomata are well developed, with their widest points opposite their posterior roots. The sagittal crest is angulated sharply downwards to the lambda which forms the most posterior part of skull. The anterior palatal notch is wide and deep; its posterior border is adjacent to the first upper premolar (PM2). The basisphenoid pits are shallow in comparison to those of M. spasma . The tympanic bullae are not greatly enlarged. In each half of the mandible, the coronoid process is short, subequal in height to the lower canine. The condyle and angular processes are robust.
Dentition
- Upper toothrow length (C-M3) averages 11.2 mm (10.6-12.1 mm). There are no upper incisors. The upper canine is powerful, with a well developed posterior basal cusp and a small antero-internal cingular cusp. The first upper premolar (PM2) is minute; it is concealed between the canine and the large second premolar (PM4) and is invisible from without (Fig. 57). PM4 has a prominent parastyle and an outwardly curved mesostylar crest. M1 and M2 are remarkable for the distortion of the W-pattern of the crowns. This results from the absence of the mesostyles and a shortening of the central commissures. The hypoconal flanges of PM4, M1 and M2 are strongly developed posteriorly (retroflexed). M3 is reduced to about half the crown area of M2; it has four cusps and two commissures.
- In the mandibular dentition, the two incisors (i1 and i2) are tricuspidate and situated adjacent to the large, sharply pointed lower canine. The anterior part of the first lower premolar (pm2) is situated on the posterior cingulum of the canine. The second premolar (pm4) slightly exceeds the crown area of pm2 and is more rectangular and less rounded in outline. The cusps of the three lower molars are situated close together with the protoconid the dominant cusp. In general, both the ectoconids and entoconids are greatly reduced, especially in m3.
Karyology
2N= 54, FN= 104; includes 13 pairs of metacentrics, 7 pairs of submetacentrics and 6 pairs telocentrics. The eighth pair of metacentrics is consistently heteromorphic in all the metaphase plates analysed; the largest metacentric of the complement is the X chromosome; the Y is the smallest dot like chromosome (Naidu and Gururaj, 1985).
Variation
All specimens from the Indian subcontinent are provisionally referred to M. l. lyra . Andersen and Wroughton, 1907 included the taxa carnatica , spectrum and schistacea as synonyms of lyra but suggested that specimens from Surat (Karnataka) and India west of 77ยช east average smaller than those of nominate subspecies and should be referred to M. l. caurina . However, this view has not been generally followed, see Brosset, 1962b; Sinha, 1970 and Corbet and Hill, 1992 and caurina is not here considered a valid subspecies.