Rhinolophus beddomei sobrinus, Andersen, 1918

Srinivasulu, Aditya, Srinivasulu, Bhargavi, Kusuminda, Tharaka, Amarasinghe, Chamara, Ukuwela, Kanishka D. B., Karunarathna, Mathisha, Mannakkara, Amani, Yapa, Wipula B. & Srinivasulu, Chelmala, 2023, Taxonomic status of the Lesser Woolly Horseshoe bats (Chiroptera, Rhinolophidae Rhinolophus beddomei) in peninsular India and Sri Lanka, Zootaxa 5301 (2), pp. 199-218 : 211-215

Rhinolophus beddomei sobrinus

Rhinolophus beddomei sobrinus Andersen 1918 Kala Oya , North Central Province, Ceylon (= Sri Lanka).

Sri Lankan Woolly Horseshoe Bat.

Diagnosis: A medium-sized Rhinolophid belonging to trifoliatus group, with an average forearm length of 57.36 ± 1.11 mm. Horseshoe is broad, does not cover the whole of the muzzle, and possesses well-developed basal lappets. One mental groove is seen on the lower lip. Sella long (50–60% of the lancet) and distinctly shaped; superior connecting process rounded off to an anteriorly-projected inferior extremity; inferior connecting process slightly wavy. Lancet high, with a broad concave lower part (about 60% from the base) and a distinctly narrower tapering upper part. Skull robust with a CCL of 22.41 ± 0.26 mm; the maxillary tooth row ( CM 3 ) is 9.58 ± 0.28 mm. Supraorbital depression deep and the supraorbital ridges are well-defined. First upper premolar ( PM 2 ) small with a distinct cusp, and is in the tooth row. The second lower premolar ( PM 3 ) is minute and is slightly extruded from the tooth row, leaving a small gap between PM 2 and PM 4 . Body covered with dense and woolly fur, which is light brown to dark greyish brown. Baculum measures 4.94 mm long with a long shaft and a two-pronged broad base .

External characters: This is a medium-sized Rhinolophid (FA 57.36 ± 1.11 mm; Table 3 ). Ears large (EL 29.50 ± 2.56 mm) and broad, with a pointed tip; antitragus well-developed and broadly triangular in shape, tragus absent; ridges 9 in number; the basal half of the ear covered with hair while the apical half scantly haired and the tip is totally devoid of hair ( Fig. 9a ); a concavity is observed on the outer border just below the tip. The lower lip has one mental groove ( Fig. 9b ). Horseshoe broad and flat, does not cover the muzzle entirely, with a well-developed, deep, and broad anterior median emargination ( Fig. 9d ). Internarial cup of the horseshoe broad, attached to the horseshoe by a narrow and short stalk, and flanked by two distinct lateral basal lappets when viewed frontally; nares teardrop-shaped and relatively large, located on either side of the base of the internarial cup. Nares large in size causing the lateral borders of the internarial cup to be upturned. Sella long (50–60% of the height of the lancet) and projects outwards ( Fig. 9e ), distinctly complex when viewed laterally, typical to species of the Rhinolophus trifoliatus group. Superior connecting process of the sella rounded off to an anteriorly-projected inferior extremity; inferior connecting process slightly wavy, connecting basally on both sides to the lateral lappets. Base of the sella broad, concave in the middle; it narrows halfway up its length towards the upper part, and the sides are parallel continuing towards a rounded-off tip ( Fig. 9c ). Lancet high, with a broad concave lower part (about 60% from the base) and a distinctly narrower tapering upper part. In the wing, the third metacarpal is much shorter than the fourth and fifth metacarpals (40.01 ± 1.5 mm vs. 45.57 ± 0.38 mm and 47.47 ± 1.62 mm respectively). The first and second phalanges of the third metacarpal are 52.26% and 83.41% of the third metacarpal respectively. The wing membrane is attached to the base of the first toe, and the interfemoral membrane is attached to the tibia ( Fig. 9h ). Body covered with dense fur. Face is hairy, but hair around eyes and the horseshoe less dense. On the ventral surface the fur extends along the forearm and a little below the anal region. The other parts of the membranes are devoid of hairs. On the dorsal surface the fur does not extend beyond the body. The penis is slender, parallel-sided, tapering to a narrowly rounded tip ( Fig. 9f, g ).

Colouration (live): Fur woolly with fur colour in live condition being greyish brown. Individual hairs have grey bases followed by dark brown to fawn middle portion and pale to white hair tips ( Fig. 6b ).

Craniodental characters: The GTL and CCL of the skull are 26.64 ± 0.87 mm and 22.41 ± 0.26 mm respectively and the skull is narrow and robust ( Fig. 10a ) ( Table 3 ). Sagittal crest well-developed, connects to the supraorbital ridges ( Fig. 10a ), and extends up to the parietal region of the cranium ( Fig. 10b ). Rostrum robust, bulged, and relatively tall. The nasal inflations are well-developed and are located median on the rostrum, anterior to a deep supraorbital depression, which is flanked by well-defined supraorbital ridges. The sagittal crest is higher than the height of the rostrum. The skull is broadest at the widest point of the zygomatic arches. Zygomatic arches wide and strong (ZB 13.12 ± 0.40 mm), with a blunt triangular dorsal arch immediately anterior to the widest point ( Fig. 10c ). The second upper premolar (PM 2) is small with a distinct cusp, situated in the tooth row in contact with the canine and PM 4. The fourth upper premolar (PM 4) is roughly 58% the height of the upper canine (C 1; Fig. 10b ). The upper tooth row (CM 3 9.58 ± 0.28 mm) is anteriorly convergent; C 1 –C 1 is about 67.86% of M 3 –M 3. The first and the second upper molars (M 1 & M 2) are equal in size. The third upper molar (M 3) is two-third the size of the first and the second molars; the metacone of M 3 is reduced and the metastyle is lacking ( Fig. 10d ). Two pairs of tricuspidate mandibular incisors (I 1 –I 3) are present ( Fig. 10 e & g ); the second lower premolar (PM 2) is small and half the height of the fourth lower premolar (PM 4); The third lower premolar (PM 3) is minute and slightly extruded from the tooth row, leaving a gap between PM 2 and PM 4 ( Fig. 10e ). The fourth lower premolar (PM 4) is about 65% the height of the lower canine, and roughly the same height as the first lower molar (M 1; Fig. 10f ). The first and second lower molars M 1 and M 2 are of the same size while the third molar M 3 is slightly smaller than the other two. The talonoid of M 3 is broader than the trigonid, and the entoconid is lacking.

Baculum: The baculum of R. b. sobrinus measures 4.94 mm long and is comprised of a thick shaft which expands into a two-pronged broad and robust base (1.76 mm) ( Fig. 11 a,b ). The base shows the presence of a deep groove on the ventral surface. The shaft is slender, ends with a broadly rounded tip and shows a concavity just below the tip which is visible in the lateral profile ( Fig. 11c ).

Ecology: The Sri Lankan Woolly Horseshoe Bat is mostly found in caves, overhanging rock ledges, tree hollows, wells, old buildings, old abandoned plumbago mines, and tunnels, in or near dense dry and tropical moist forests, typically hanging by one foot, with the wings wrapped around the body. They live solitary, in pairs or in small parties of up to four individuals. They produce one to two pups per brood in Sri Lanka ( Phillips 1980; Edirisinghe et al. 2016; Kusuminda et al. 2018). It has been recorded at elevations ranging from 43 m asl to 462 m asl (one specimen from Medamahanuwera, Central Province was found at 1077 m asl; Bates & Harrison 1997).

Distribution: The Sri Lankan Woolly Horseshoe Bat is endemic to Sri Lanka. It has been recorded from many parts of the island except the northern and the eastern Provinces. The northernmost and southernmost records of the species are from Kala Oya (North Central Province) and Thalgasmankada (Southern Province) respectively.

Figures

FIGURE 6. Coloration of dorsal fur (in live condition) of a—Rhinolophus b. beddomei and b—R. b. sobrinus.

FIGURE 9. External features of Rhinolophus b. sobrinus [a—structure of ear; b—close-up view of lower lip, showing one mental groove; c—frontal view of head and ventral view of the sella; d—frontal view of noseleaf; e—lateral view of noseleaf; f—frontal view of penis; g—lateral view of penis; h—hind foot].

FIGURE 10. Skull and mandible of Rhinolophus b. sobrinus [a—dorsal view of skull; b—lateral view of skull; c—frontal view of skull; d—ventral view of skull; e—dorsal view of mandible; f—lateral view of mandible; g—frontal view of mandible; Scale: 5 mm].

FIGURE 11. Baculum structure of Rhinolophus b. sobrinus [a—dorsal view; b—ventral view; c—lateral view; Scale: 1 mm].