Dibamus floweri, Quah & S & Grismer & Grassby-Lewis, 2017

Quah, Evan S. H., S, Shahrul Anuar M., Grismer, L. Lee & Grassby-Lewis, Rupert, 2017, A new species of Dibamus Duméril & Bibron 1839 (Squamata: Dibamidae) from a hill station in Peninsular Malaysia, Raffles Bulletin of Zoology 65, pp. 681-690 : 682-688

Dibamus floweri , new species

Flower’s blind lizard ( Figs. 1 , 2 ; Table 1)

Material examined. Holotype, LSUHC 12481 , male collected by Rupert Grassby-Lewis on 26 July 2015 from Fraser’s Hill , Pahang, Peninsular Malaysia at approximately 2100 hrs at (3°42′53.0″N 101°44′58.6″E), approximately 1,500 m above sea level.

Paratype. The female paratype ZRC 2.7240 was collected by Evan Quah and Alex Figueroa on 7 February 2017 along the Gap road below Fraser’s Hill at approximately 1000 hrs at (3°41.912′N, 101°43.920′E), 1,207 m above sea level .

Diagnosis. Dibamus floweri , new species, differentiated from all other congeners by this combination of characters: maximum SVL of 112 mm; tail length 11.4–15.2% of SVL; labial, nasal sutures absent; rostral suture present but incomplete; single postocular; four scales bordering posterior edge of first infralabial; no enlarged, medial, sublabial scale; 21 midbody scale rows; 23 transverse scale rows just posterior to head; 21 transverse scale rows just anterior to vent; 175–194 ventral scales; 23–46 subcaudal scales; relative size of frontal to frontanasal 1.1–1.5; relative size of interparietal to surrounding scales 1.3–1.8; and light coloured bands on the body. These characters are scored across all nominal species of Dibamus in Table 2.

Description of holotype. SVL 112 mm; tail 17 mm (15.2% of SVL); head slightly longer (HL 2.66 mm) than wide (HW 2.48 mm); snout bluntly rounded, projecting beyond jaw; teeth small, acute; ES 1.93 mm; EN 1.49 mm; IN 0.83 mm; IO 1.31 mm; labial and nasal sutures absent; rostral suture present but incomplete; rostral pad with numerous, evenly distributed papillae; single postocular scale; the rostral pad is bordered posteriorly by single supralabial and ocular scale; eyes barely visible below ocular scale; three scales posterior to supralabial; frontal relatively large, 1.1 times its width of frontonasal; frontonasal three times wider than long; interparietal bordered posteriorly by three smaller nuchal scales; relative size of interparietal to nuchal scale 1.3; mental triangular, bordered by first infralabial on each side; five scales contacting first infralabial, a medial scale behind the mental and four other scales posterior to the infralabial ( Fig. 2 ).

Body wormlike, almost cylindrical: midbody width 3.55 mm; tail width 3.11 mm (BW/TW = 1.14); body scales smooth, subcycloid; 21 midbody scale rows; 23 scale rows just posterior to head; 21 scale rows anterior to vent; scales near vent thick; 46 subcaudals; 194 ventrals; vestigial hind limbs present, flap-like, flattened, curved inward, lacking toe pads, covered by imbricating scales ( Fig. 2E ); four scales between base of hind limbs; three large dorsal scales on distal portion of hind limb; length of right and left hind limbs 3.9 mm; tail tip blunt, covered by a single rounded scale, not terminating in a spine. All meristic data listed in Table 1.

Colouration in life. The labial and nasal scales are beige to opaque; dorsum, flanks and tail gray-brown; ventral surface lighter; anal region dull-white. Slightly beyond midway down the body is a broad silver-gray band, approximately 10–12 body scales in length that encircles the body ( Fig. 1A ).

Colouration in preservation. Rostral and mental pads opaque, gray or blue; dorsum and flanks pale-brown; ventral surface lighter brown; tail darker brown; subcaudal region lighter brown. The body band gray; body scales are brownish, dark centrally and transparent on posterior edges ( Fig. 2 ).

Variation. The female paratype is similar to the holotype in morphology ( Table 1) with the major difference being the absence of the two, short, flap-like hind limbs in the female which are only present in males and higher number of ventral (194 vs. 170) and subcaudal (46 vs. 23) scales in males which may be sexually dimorphic. The paratype also differs from the holotype in the location of the band of the body, which is on the posterior end of the body and the tail. It was observed that the paratype could alter the width of the band when it felt threatened ( Fig. 1B, C ). In addition, when in preservation the head of the paratype lightened compared to the rest of the body and an additional body band became visible on the anterior quarter of the body.

Comparisons. The absence of a labial and nasal suture in Dibamus floweri , new species, distinguishes it from D. alfredi Taylor, 1962 ; D. bogadeki Darevsky, 1992 ; D. booliati Das & Yaakob, 2003 ; D. dalaiensis Neang, Holden, Eastoe, Seng, Ith & Grismer, 2011 ; D. deharvengi Ineich, 1999 ; D. dezwaani Das & Lim, 2005 ; D. ingeri Das & Lim, 2003 ; D. kondaoensis Honda, Ota, Hikida & Darevsky, 2001 ; D. nicobaricum ( Steindachner, 1867) ; D. novaeguineae Duméril & Bibron, 1839 ; D. somsaki Honda, Nabhitabhata, Ota, & Hikida, 1997 ; D. tebal Das & Lim, 2009 ; D. tiomanensis Diaz, Leong, Grismer & Yaakob, 2004 ; and D. vorisi Das & Lim, 2003 . The presence of an incomplete rostral suture further distinguishes it from D. celebensis Schlegel, 1858 ; D. leucurus ( Bleeker, 1860) ; D. seramensis Greer, 1985 ; D. smithi Greer, 1985 ; and D. taylori Greer, 1985 . The presence of four scales on the posterior edge of the infralabial distinguishes it from D. bourreti Angel, 1935 (four vs. two); D. greeri Darevsky, 1992 (four vs. one and three); and D. montanus Smith, 1921 (four vs. two). Other differences between the new species and other congeners are presented in Table 2.

Among the Peninsular Malaysian species, D. floweri , new species, is further differentiated from both D. booliati and D. tiomanensis by the presence of an incomplete rostral suture as opposed to its absence in the other two species. It is also differentiated from D. tiomanensis by the lower number of midbody scale rows (21 vs. 25–26), lower number of subcaudal scales in both males (46 vs. 50) and females (23 vs. 45–48), and the presence of bands of the body versus their absence in D. tiomanensis ( Diaz et al., 2004) . From D. booliati , D. floweri , new species differs by the higher number of midbody scale rows (21 vs. 20), lower number of subcaudals in females (23 vs. 24–39) and the presence of the body band being on the posterior region of the body versus the band being in the neck region ( Das & Yaakob, 2003). In addition, D. tiomanensis is restricted to the islands of Tioman and Tulai off the east coast of Peninsular Malaysia while D. booliati is a lowland species collected at 121 m a.s.l. in elevation near a limestone cliff at Batu Gua Madu, Kelantan. By comparison, D. floweri , new species, is a montane species that has so far only been recorded above 1,200 m a.s.l. in elevation at Fraser’s Hill, Pahang.

EMS – –

RS – +

NS + –

LS + –

B – –

)

SVL 16 16.8

TL

%

of – 15 6.1 –

(

.

Max SVL 123 90.1

size of

Interparietal 1.8 1

Relative

Frontal 1.2 1.2

of

scales Female – 45 48 46.5 2 11 11 1 Number subcaudal Male 50 50 1 33 33 1

Mid-body scale rows

26 – 25 25.3 3 20 20 2

Number of scales posterior of interparietal 4?

Number scales of edge of on infralabials 4 3) () 2 (3

Number

post- of oculars 1 (3) (2) 2

of

Species

Dibamus tiomanensis vorisi

Etymology. The specific epithet, floweri , is in honour of Major Stanley Smyth Flower, who was one of the pioneers for herpetological discoveries in the Malay Peninsula. He made many notable discoveries over the course of his explorations in the region and his natural history observations well over a century ago were very detailed and contributed tremendously to improving our understanding of the ecology and behaviour of many species to this day.

Distribution. Dibamus floweri , new species, is presently known only from Fraser’s Hill, Pahang, Peninsular Malaysia at elevations between 1,207 and 1,500 m ( Fig. 3 ).

Natural history. Both specimens were found while digging through leaf litter that had accumulated along the banks of roads. The holotype was discovered at night in a drainage ditch along Jalan Girdle in a damp and shaded area. The paratype was uncovered during the day underneath approximately 3 cm beneath the soil ( Fig. 2F ), and in the same pile of leaflitter, the skink, Larutia miodactyla ( Boulenger, 1903) was also found. When handled, both specimens flared up their body scales, giving them a wrinkled appearance ( Fig. 1C ). This behaviour is interpreted as a defensive, anti-predator mechanism employed by Dibamus to mimic a possible nonpalatable species of worm ( Darevsky, 1992). The other two Peninsular Malaysian species, D. booliati and D. tiomanensis display the same behaviour when agitated ( Das & Yaakob, 2003; Diaz et al., 2004; Grismer, 2011).

Figures

Fig. 1. (A) Holotype of Dibamus floweri, new species (LSUHC 12481) from Fraser’s Hill, Pahang (Photograph by Rupert Grassby-Lewis). (B) Paratype of Dibamus floweri, new species (ZRC 2.7240) from Fraser’s Hill, Pahang at ease (C) Paratype of Dibamus floweri, new species (ZRC 2.7240) from Fraser’s Hill, Pahang when agitated. Note the rugose appearance of the skin. Photographs by Evan Quah.

Fig. 2. (A) Full body; (B) Dorsal view of the head; (C) Ventral view of the head; (D) Lateral view of the head of the female paratype of Dibamus floweri, new species (ZRC 2.7240). (E) Hind limbs of the male holotype of Dibamus floweri, new species (LSUHC 12481). (F) Leaf litter microhabitat at Fraser’s Hill, Pahang where the paratype of Dibamus floweri, new species, was found.

Fig. 3. Distribution of Dibamus species in Peninsular Malaysia.