Andersen, 1906
Andaman Horseshoe bat
External characters (Table 33)
This species, with an average forearm length of 39.4 mm (37.5-40.7 mm), is comparable in size to R. lepidus . The sella is of the R. pusillus type (Fig. 73) but relatively larger; the connecting process is horn-like and slightly curved downwards; its development is emphasised by the marked concavity evident in the anterior border of the sella. The lancet is tall and the noseleaf, including both the horseshoe and the lancet ranges from 11.9-13.3 mm in greatest height; the breadth of the horseshoe ranges from 6.5-7.1 mm.
Cranial characters
The skull of the holotype of R. c. cognatus is relatively large. Its condylo-canine length (15.8 mm) exceeds that of R. lepidus (13.8-15.5mm). The skull of R. c. famulus is smaller with a condylo-canine length of 14.2 mm. The sagittal crest is well developed in cognatus and the rostrum is broad with the median rostral inflations well developed.
Dentition
- The dentition of R. c. cognatus is robust. Upper toothrow length (C-M3) averages 6.5 mm (6.0-7.0 mm). The first upper premolar (PM2) lies within the toothrow and is apparently functional.
- The second lower premolar (pm3) also lies within the toothrow; the first (pm2) and third (pm4) premolars are sometimes in contact.
Variation
This species is very little known. Specimens from South Andaman Island are referable to the nominate race R. c. cognatus . Those from North Central Andamans and Narcondam Island are significantly smaller and have been tentatively referred to R. c. famulus (Sinha, 1973; Hill and Yoshiyuki, 1980).