Rhinolophus thailandensis, Wu & Harada & Motokawa, 2009

Wu, Yi, Harada, Masashi & Motokawa, Masaharu, 2009, Taxonomy of Rhinolophus yunanensis Dobson, 1872 (Chiroptera: Rhinolophidae) with a description of a new species from Thailand, Acta Chiropterologica 11 (2), pp. 237-246 : 238-242

Rhinolophus thailandensis sp. nov.

( Figs. 1–2 ) Rhinolophus yunanensis [in partim]; Lekagul and McNeely,

1977: 154; Hill, 1986: 15; Yoshiyuki, 1990: 37; Corbet and

Hill, 1992: 97; Csorba et al., 2003: 84; Simmons, 2005: 365.

Diagnosis

The largest species of the pearsoni group of the genus Rhinolophus , with a large skull and long ears. Baculum with a basal cone about one-fourth of its length; its front part projects out, becoming salient. Anterior swelling is high; the corner of the zygoma projects out on the left and right sides of the skull with a small arc sunk back into the zygoma on both sides. Second lower premolar (PM 3) is present, but is very small and outside the tooth row, with a small diastema between both PM 2 and PM 4.

Etymology

Rhinolophus thailandensis is named after the country of the type locality: ‘ Thailand.’

Holotype

Adult male, KUZ-M5000 (original collector’s number 1249) from a cave, Doi Chang Kiang, Chiang Mai, Thailand, at an altitude of 1,790 m, collected on 2 February 1982 by Masashi Harada, Songsakdi Yenbutra, Preecha Nunpakdee , and Niphan Ratanawarabhan. Holotype has been preserved in alcohol, with the skull extracted, and is deposited in the Kyoto University Museum, Kyoto, Japan. Measurements of the holotype (in mm) are as follows: FA 60.39, HB 64.56, TL 24.33, HF 14.15, Tibia 30.02, Ear 29.11, CCL 24.80, IOW 2.90, ZW 14.09, BW 11.44, MW 12.45, UCCW 7.43, UMMW 10.52, UCML 11.41, ML 19.59, and LCML 12.13.

Paratypes

Six adult males and two adult females: NSMT- M28581 , ♀; 28799 , ♀; 28800 , ♂; 28801 , ♂; 28802 , ♂; 28803 , ♂; 28804 , ♂; and 28805 , ♂, from a cave, Doi Inthanon , Chom Thong, Chiang Mai, Thailand, 18°35’N, 98°29’E, collected on 2 September 1987 by Mizuko Yoshiyuki, Preecha Luecha, Lakkhana

Boonliang, Punya Saengmala, and Prasarn Bangplub (reported as ‘ R. yunanensis ’ by Yoshiyuki, 1990). All of the specimens were preserved in dry skin, with the skulls extracted, and are deposited in the National Museum of Nature and Science, Tokyo, Japan.

Other Specimen Examined

One adult female deposited in the Thailand Institute of Scientific and Technological Research, Bangkok, Thailand. Collecting data are the same as the holotype. This specimen is used only for karyological analysis in this study and has been reported by Harada et al. (1985).

Description of the Species

The largest species (FA 56.22–61.16 mm) of the pearsoni group, with the longest ears, measuring 29.11–32.00 mm ( Table 1 ). Noseleaves are typical for the pearsoni group. Anterior noseleaf covering the muzzle, with a short gap in the middle between the left and right leaves. Secondary noseleaf absent. Connecting process arc, originating below the apex of the sella, and falling down. Height of sella (6.42 mm) is longer than its width, pagoda-shaped, with a narrow upper part (2.70 mm), and wider base (3.78 mm). Fur (based on fluid-preserved body of the holotype) from the dorsal aspect; hairs in mid-

dorsal region measure approximately 12.44 mm; hair bases are whitish, pale, tips are buffy brown to deep brown; those on nape of shoulders are darker. Ventrally, hairs are short, 8.97 mm in mid-ventral region, and almost the same length on the flanks and outer aspects of the throat. Hair bases are grey, onethird of tips are buffy brown. Membranes are uniform, slightly dark brown. Third metacarpal is shortest, the fourth of medium length, and the fifth is longest.

Skull ( Fig. 1 ) is the largest (CCL 22.86–24.80 mm) in the pearsoni group and has a higher anterior swelling, with two bulbous swellings in the top. The corner of the zygoma projects out and is salient on both the left and right sides of the skull, with a small arc sunk back on both sides. Teeth are large in the ventral view. The first upper premolar (PM 2) is small but present, the second lower premolar (PM 3) is present with a distinct cusp between PM 2 and PM 4 ( Fig. 1 ), but is very small and outside the tooth row.

Baculum ( Fig. 2 ) are similar in general outline to that of the pearsoni group. The basal cone is not very large and strong compared to the others; the shaft is roughly cylindrical. The total length of the baculum is 4.02 mm, and the width is 0.25 × 0.45 mm. The width of the basal cone is 1.09 × 1.14 mm. The tip of the shaft is narrowly rounded off, with lateral widening. The basal cone about one-fourth the length of the baculum length, with a width four times the shaft width, and a projecting front.

Karyotype

The karyotype of R. thailandensis was reported to be 2 n = 60, FN = 64 as ‘ R. yunanensis ’ based on

two specimens by Harada et al. (1985). The holotype is one of the specimens reported by Harada et al. (1985). Autosomes consist of two metacentric, one submetacentric, and 26 acrocentric pairs, and the X and Y chromosomes are subtelocentric and acrocentric, respectively ( Harada et al., 1985 — Fig. 3 ). One autosomal pair of acrocentric chromosomes (no. 14) has secondary constrictions adjacent to the centromere.

Comparisons

Rhinolophus thailandensis belongs to the pearsoni group in the genus Rhinolophus , according to a key provided by Csorba et al. (2003): that is, it is documented from outside the Palaearctic region (key no. 10), and from the Indomalayan, Oceanian, and Australian regions (24); its sella lacks lateral basal lappets (26); its connecting process is rounded, not pointed (32), and is usually better developed, and the tip is pointed more or less forward; its zygomata are more robust, and medio-laterally flattened (34); its connecting process forms a continuous arch or obsolete (35); its lower lip has one mental groove; and the internarial region is not expanded (36). The pearsoni group thus includes four species: R. thailandensis , R. yunanensis , R. pearsoni , and R. chiewkweeae .

Rhinolophus thailandensis differs from the other three species of the pearsoni group and is the largest species of this group, as expressed in greater values for FA: R. thailandensis compared with R. yunanensis from Yunnan and Sichuan, R. pearsoni from Sichuan and Thailand ( Table 1 ), and R. chiewkweeae (56.1 ± 0.81: Yoshiyuki, 2005). Also, the ear length of R. thailandensis is much greater than R. yunanensis from Yunnan and Sichuan; R. pearsoni from Sichuan and Thailand ( Table 1 ); and R. chiewkweeae (25.0 ± 0.76: Yoshiyuki, 2005).

The sella of R. thailandensis is similar to R. pearsoni , but it differs from those of all species of the pearsoni group by its larger size (13.35 × 10.54 mm [width × height] for the holotype) compared with 10.56 (10.02–11.09 in range, n = 3) × 8.50 (8.19– 8.89, n = 3) in R. yunanensis from Sichuan and 10.19 (9.73–10.83, n = 10) × 8.92 (8.04–9.29, n = 10) in R. pearsoni from Sichuan.

Rhinolophus thailandensis is further distinguished from the other species of the pearsoni group in skull characteristics, as follows: (1) anterior

median swellings width in dorsal view — AMSW, following the definition by Csorba et al. (2003) — is 4.66 mm and greater than R. yunanensis (4.06); (2) the corners of the zygoma project out on the left and right sides of the skull (as shown in greater ZW) and have a small arc sunk back on both sides, but the ZW is smaller and the sunken arc is not clearly seen in R. yunanensis ; (3) teeth are larger in ventral view, as shown in the greater UMMW ( Table 1 ).

The baculum of R. thailandensis has a very long, but not very strong, basal cone compared with the bacula of R. yunanensis and R. pearsoni . The basal cone is about one-fourth of the baculum length, instead of one-half in R. yunanensis and one-third in R. pearsoni . The entire shaft is roughly cylindrical, and its basal cone width is about four times the shaft width in ventral view, versus nine times in R. yunanensis and 8.5 times in R. pearsoni , and the front part is salient in the lateral view in R. thailandensis , whereas it projects out on the back part in R. yunanensis .

In the PCA of nine cranial characters, the first and second principal component axes explained 71.7 and 10.5% of the total variation, respectively. In the first axis, all variables showed positive loading (CCL 0.364, IOW 0.175, ZW 0.360, MW 0.356, UCCW 0.309, UMMW 0.331, UCML 0.372, ML 0.336, and LCML 0.352). In the second axis, IOW (positive, 0.826) and UCCW (negative, -0.389) showed relatively large loading (for others, CCL -0.020, ZW 0.187, MW 0.147, UMMW 0.071, UCML -0.150, ML -0.015, and LCML -0.285). In the first axis ( Fig. 4 ), individual scores were large in R. thailandensis and small in R. pearsoni from Thailand. In R. yunanensis from Sichuan and Yunnan, individual scores were intermediate and overlapping with those of R. pearsoni . In the second axis, values were smaller in R. pearsoni from Thailand than in R. pearsoni from China. In the twodimensional plots, R. thailandensis and R. yunanensis specimens were completely separated. Plots for R. yunanensis were close and slightly overlapping with R. pearsoni from China.

The karyotypes of R. thailandensis (2 n = 60, FN = 64: Harada et al., 1985) and R. yunanensis from Sichuan (2 n = 46, FN = 60: Wu et al., 2006) differ in the number of large metacentric or submetacentric pairs. There is one pair in R. thailandensis and there are seven pairs in R. yunanensis from Sichuan. These karyological differences are distinctive, and major chromosome rearrangements may have occurred between R. thailandensis and R. yunanensis .

Distribution

Rhinolophus thailandensis currently is represent- ed only by specimens from Chiang Mai in northern Thailand. Future comprehensive examinations of specimens referred to as ‘ R. yunanensis ’ from the entire distribution range, including China and Thailand, as well as northeastern India and northern Myanmar, need to be performed to correctly understand the distribution of R. thailandensis and R. yunanensis .

Figures

FIG. 1. Dorsal, ventral, and lateral views of the skull and mandible of R. thailandensis from Doi Chang Kiang, Chiang Mai, Thailand (A: holotype, KUZ-M5000) and R. yunanensis from Emei-shan, Sichuan Province, China (B: IBHG 04301). Bar indicates

FIG. 2. Ventral (left) and lateral (right) views of the baculum of R. thailandensis from Doi Chang Kiang, Chiang Mai, Thailand (A: holotype, KUZ-M5000) and R. yunanensis from Emei-shan, Sichuan Province, China (B: IBHG 04302). The bar represents

FIG. 3. The conventional karyotype (2n = 60) of R. thailandensis from Doi Chang Kiang, Chiang Mai, Thailand (one female TISTR specimen)

FIG. 4. Two-dimensional plots of the first and second principal component scores (PCA) on the basis of nine cranial characters for R. thailandensis, R. yunanensis, and R. pearsoni