2004

Asiatic Herpetological ResearchVol. 10, pp. 1-7

A New Species of Dibamus (Squamata: Dibamidae) from West Malaysia
RAUL E. DIAZ1,2,*, MING TZI LEONG3, L. LEE GRISMER1, AND NORSHAM S. YAAKOB4
1Department of Biology, La Sierra University, Riverside, CA 92515-8247, USA
2Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA*Corresponding author E-mail: rauldiaz@berkeley.edu
3Department of Biological Sciences, National University of Singapore, Kent Ridge,Singapore 119260, Republic of Singapore
4Forest Research Institute Malaysia, Kepong, 52109 Kuala Lumpur, Malaysia

Abstract. - A new lizard of the genus Dibamus is described from Pulau Tioman and Pulau Tulai, Pahang, WestMalaysia. This species most closely resembles D. novaeguineae, D. kondaoensis, D. leucurus and D. montanus, butdiffers from all congeneric species in exhibiting the following combination of characters: postoculars 1, scales bordering first infralabial 4, SVL 123 mm, 25-26 midbody scale rows, frontonasal and rostral sutures complete, and thepresence of slightly posteriorly notched cycloid body scales as an adult.
Key words. - Dibamus, Dibamus tiomanensis, new species, Dibamidae, Pulau Tioman, West Malaysia.

Introduction
The genus Dibamus presently contains 18 species (seeGreer, 1985; Darevsky, 1992; Das, 1996; Honda et al.,
1997; Ineich, 1999; Honda et al., 2001; Das and Lim,
2003; Das and Yaakob, 2003), a two-fold difference
from the detailed review of the group by Greer (1985).
Species of the genus Dibamus collectively range
throughout southeast Asia, from southern China and thePhilippines through Indonesia. Dibamus alfredi wasdescribed by Taylor (1962) from Thailand. D. alfredi
were later found on the island of Nias, off the west coastof Sumatra (Greer, 1985) and from Danum Valley in
Sabah State, Borneo (Tan, 1993; Das and Yaakob, 2003).
A large gap was then left between Thailand and Borneo.
Lim and Lim (1999) reported D. cf. alfredi from Pulau
Tioman. Upon examination of their specimen, one from
Pulau Tioman, and another from P. Tulai, we conclude
that these specimens constitute a new species describedherein. Pulau Tioman lies between longitudes 104° 7' to104° 15' E and latitudes 2° 44' to 2° 54' N (Bullock andMedway, 1966). Finding another endemic population on
this island provides another reason for its conservation
as well as further studying its rich herpetofauna.

Material and Methods
Single females from both Pulau Tulai and Pulau Tioman
were collected, fixed in 10% formalin, and preserved in
70% ethanol. Both specimens were deposited in the
Zoological Reference Collection (ZRC) at the Raffles
Museum of Biodiversity Research. Sliding calipers wereused for all length measurements. Terminology used follows Greer (1985) and Honda et al. (1997). Individuals© 2004 by Asiatic Herpetological Researchwere sexed externally under a dissecting microscope;males were identified by having two small, flap-likelimbs (one on each side of the vent) (Duméril andBibron, 1839).

Taxonomy
Dibamus tiomanensis, new species
Figs. 1, 2
Holotype. - ZRC.2.3410, adult male collected at
Kampung Paya, Pulau Tioman, Pahang, West Malaysia(Fig. 2) on 16 September 1995.
Paratypes. - Adult female (ZRC 2.5092) collected along
the trail to Bukit Bakau, Pulau Tulai, West Malaysia(Fig. 2) collected 14 July 2001. Juvenile female(ZRC.2.5260) collected along the Tekek-Juara Cross
Island Trail, Pulau Tioman, West Malaysia collected 11July 2001.
Diagnosis. - Dibamus tiomanensis differs from all otherspecies of Dibamus in having cycloid scales which areslightly notched posteriorly as an adult and flat cycloid
light brown dorsal scales with cream borders as a juvenile. It also differs from other Dibamus in having the following combination of characters: rostral sutures incomplete; nasal and labial sutures complete; scales bordering
posterior edge of first infralabial 4; postocular 1; transverse scale rows just posterior to head 29, at midbody
25, proximally anterior to vent 21; subcaudals 45; snout
blunt in lateral profile (Fig. 1; Table 1); presacral vertebrae 124; postsacral vertebrae 23 (Table 3).

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Figure 1. Photograph of Dibamus tiomanensis, new species, on forest leaf litter.

Description of holotype. - Snout-vent length 92.5 mm;
tail length 13.1 mm; midbody diameter 2.5 mm. Snout
bluntly rounded; nostril lateral; rostral pad with large
number of evenly distributed sensory papillae; rostral
sutures incomplete; nasal sutures complete from nostril

to ocular; labial sutures complete from anterior part ofnasal suture to mouth; frontonasal six times wider thanlong; frontal approximately 1.05 times wider than frontonasal; interparietal bordered posteriorly by four slightly smaller nuchal scales; postocular one; supralabialone; scales bordering posteromedial edge of first infralabaial four; ear opening absent; eyes dimly visible
through ocular; body scales notched posteriorly; transverse scale rows just posterior to head 23, at midbody
25, at just anterior to vent 23; subcaudals 50; tip of tailblunt, not terminating in a spine; hind limb length 2.6mm.
Description of paratypes. - The paratypes (bothfemales) are similar to the holotype in all aspects except
the following: transverse scale rows posterior to head29, transverse scale rows anterior to vent 21 and 22, andsubcaudals 45 and 48.
Variation. - Paratype ZRC.2.5260 is the only juvenile.
It shows a possible ontogenetic change in scale morphology. Juveniles have cycloid, flat, and light browncream bordered scales. Adults have posteriorly notchedbrown scales.

Figure 2. Lateral (A), dorsal (B), and ventral (C) view ofhead of Dibamus tiomanensis, new species. (f: frontal,fn: frontonasal, ip: interparietal, if: first infralabial, l: labial
suture, m: mental, n: nasal suture, o: ocular, po: postocular, sl: supralabial)

Color in life. - Adults have a brown ground color both
dorsally and ventrally, except on the snout and jaws
which are a lighter shade of brown. Juveniles have acream-colored snout and jaws which contrast well withthe darker spotted sensory papillae and body scales
which are light-brown bordered with cream. Mantheyand Grossman (1997:205) present a color photograph ofthe holotype.

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Table 1. Comparison of several scale characters and measurements within Dibamus. The size of the frontal is measured relative to the frontonasal and the interparietal relative to the surrounding anterior body scales. Sample sizes for
postoculars and scales on posterior edge of infralabials are given in parentheses. Entries for midbody scale rows andsubcaudal scales are as follows from top to bottom: range, mean, and sample size (modified from Greer, 1985). (*= 1& 3 refer to 1 scale present on the left infralabial and 3 on right; **=tail regenerated; *** = text in Das and Yaakob (2003)
mentions 3 scales bordering the infralabials in diagnosis, whereas 4 scales are mentioned in description of holotype).
Scales on
posterior Mid-bodyedge of scale rows
infralabial

Subcaudal Scales
Females
Males

Relative size of:
Frontal Interparietal

Max.
SVL

Tail
Length(% of SVL)

20-21
20.3
3

46-47
46.5
2

41-46
43.5
2

1.4-2.0

1.7-2.2

135

17-182(1)

2323
151
51
1---

177**

22.5

1(2)

3(2)***

20
20
1-

24-39
31.5
2--

102.7

9.4-13.0

bourreti

1(1)

2(1)

24
24
1-52+
52+
1

2.3

4.5

151

23+

celebensis

2(10)
3(3)

3(6)
4(7)

26-30
27.4
13

38-40
39.3
3

35-40
38.0
4

1.2-2.3

1.0-2.9

188

10-13

deharvengi

1(1)

2(1)

16
16
157
57
1-

1.3

1.4

92

22.4

greeri1(3)1&3(2)*

20
20
153
53
154
54
1--86

23-28

ingeri

2(1)

3(1)

20
20
136
36
1-

1.5

1.096

14.8

kondaoensis

2(1)

3(1)

23
23
1

59
59
1-

1.03

1.0

112.4

19.4

leucurus

1(23)

3(21)
4(2)

20-23
21.0
23

48-52
49.5
4

41-47
43.5
4

1.2-4.2

1.0-3.1

136

16-20

montanus

1(2)

2(2)

22
22
2

49
49
1

43
43
1

2.0

2.2

130

15-18

nicobaricum

1(6)

4(6)

23-25
24.6
6

34-38
35.6
3

31-36
34.3
3--

134.7

8.7-18.3

novaeguineae

2(92)
3(2)

3(53)
4(41)
5(1)

22-26
24.5
107

42-45
43.0
6

37-42
39.6
9

1.0-3.0

0.7-2.4

158

9-19seramensis

4(1)

4(1)

33
33
1-40
40
10.7

1.2

203

11

smithi

1(1)
2(4)

2(5)

18-19
18.8
559
59
159-6160.0
3

1.5-2.3

1.3-2.0

108

21-24

Dibamus

Postoculars

alfredi

2(4)

3(3)
4(1)

bogadeki

1(1)booliati

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Table 1. Continued.
Scales on
posterior Mid-bodyedge of scale rows
infralabial

Subcaudal Scales
Females
Males

Relative size of:
Frontal Interparietal

Max.
SVL

Tail
Length(% of SVL)

18-19
18.5
4

44**-5851
227**-57
422

1.1-1.27

1.0-2.16

106

18-24

2(2)
3(14)
4(4)

22-28
23.4
2241-5548.4
541-5248
7

0.2-1.3

1.0-1.2

169

14-19

1(3)

4(3)

25-26
25.3
350
50
145-48
46.5
2

1.2

1.8

123

15-16

2(2)

3(2)

20
20
2

33
33
1

11
11
1

1.2

1.0

Dibamus

Postoculars

somsaki

1(4)

2(4)

taylori

3(13)
4(6)

tiomanensis

vorisi89.2-90.1 6.1-16.8

Figure 3. Map of Southeast Asia showing the distributionof known Dibamus tiomanensis specimens. (1) Trail toBukit, Pulau Tulai, (2) Tekek-Juara Cross island trail on
Pulau Tioman (from Kg. Tekek to Kg. Juara)

Etymology. - This species is named after the type locality for the holotype (Pulau Tioman = Tioman Island)
Distribution. - Endemic to Pulau Tioman and adjacentPulau Tulai (Fig. 2).
Comparisons. - Dibamus tiomanensis was listed as D.
cf. alfredi owing to its geographic proximity to D. alfredi, which occurs in Peninsular Malaysia and Thailand(Manthey and Grossman, 1997; Taylor 1963). The presence of four scales bordering the first infralabial posteriorly differentiates the new species, Dibamus tiomanensis, from D. bogadeki, D. booliati, D. bourreti, D. deharvengi, D. greeri, D. ingeri, D. kondaoensis, D. montanus, D. smithi, D. somsaki, and D. vorisi. In having
one post ocular present, D. tiomanensis differs from D.
alfredi, D. celebensis, D. novaeguineae, D. seramensis,and D. taylori. From the remaining two congeners, D.

Figure 4. Lateral (A), dorsal (B), and ventral (C) view ofheads of Dibamus alfredi (left) and Dibamus
novaeguineae (right). Figures from Greer (1985). [f:frontal, fn: frontonasal, ip: interparietal, if: first infralabial,
l: labial suture, m: mental, n: nasal suture, o: ocular, po:postocular, sl: supralabial]

tiomanensis differs from D. montanus Smith, 1921
(Langbian Plateau, Vietnam) in having more pre-sacralvertebrae (124 vs. 112-114) and D. leucurus (Bleeker,1860) (Sumatra, Borneo) in the presence of slightly posteriorly notched cycloid scales as an adult.

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Table 2. Matrix of diagnostic characters and their states for species of Dibamus (modified from Greer, 1985).

Dibamus

Rostral suturecomplete andLabial suture
separate (+),
complete (+),
Nasal sutureFirst infralabial
No. of postcomplete and complete (+), incomplete dor- surrounded by ocular scales
meeting (-),
reduced (-), or sally to varying 1(+), 2 (-), 3(0), 1(+), 2(-), 3(0),incomplete (0)degrees (-), orabsent
4(1), or 5(2)or 4(1)or absent (1)absent (0)scalesBody scales
cycloid (+) orcycloid andslightly
knotched
posteriorly (-)
in adults

alfredi0--0,1-+

bogadeki0++-++booliati

1-+-++bourreti

++

0

-++

celebensis

0++0,1-,0+deharvengi

-++-

++

greeri

0

-+

0*++

ingeri0++0-+kondaoensis

0++

0

-

+

leucurus

0-+

0,1++

montanus-++0++

nicobaricum

+++

1++

novaeguineae

0++0,1,2-,0+seramensis

0++

1

1+

smithi

0-

0

-+,-

+

somsaki-++-++

taylori

0++-,0,1

0,1+

tiomanensis

0++1+-vorisi

0+00-+* = See Table 1 for information on this character state.

D. nicobaricum is included in this study followingDas' (1996) redescription and reevaluation of the species(in which it is inaccurately referred to as D. nicobaricus
through parts of the paper) despite Honda et al. (2001)
avoidance of it's recognition as a nominate species.
Great difficulty arises in finding specimens ofDibamus for study due to their fossorial lifestyle. As aresult, many descriptions are based on 2-5 individuals.
An unusually large collection of D. novaeguineae from

Mt. Canlaon, Negros Island, Philippines (Greer,1985:150) has given a unique insight to how variablemorphological characters can be within a single population (See Table 1). Further studies are needed in studying variation within this family as slight character statevariances have warranted the recognition of new species[See Das and Lim (2003), Das and Yaakob (2003), andthis paper] which may prove to be a variant of an alreadydescribed taxon.

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Table 3. Sacral vertebrae count of described species ofDibamus.
Dibamus

Sacral vertebrae
pre-sacral
post-sacral

alfredibogadekibooliatibourreticelebensis
deharvengi
greeriingerikondaoensis
leucurusmontanus
nicobaricum
novaeguineae
seramensis
smithisomsakitayloritiomanensis
vorisi116-126
134
113-120
115-129
117-132120
96-11197140
106-135
112-114124
109-125130
130-137
119
112-135
124
97

22-26
25
11-25
12-40+
17-22
36
28-31
21
33
21-28
24-27
23
18-24
18
30-34
31
21-29
23
20

Natural History
The holotype was found under a large stone in Kampung
Paya, Pulau Tioman. ZRC 2.5092 was found beneathleaf litter in loose dirt adjacent to a large rock and bamboo stands in secondary forest along the trail to Bukit
Bakau on Pulau Tulai at 20 m elevation. ZRC.2.5260
was found beneath a decaying log one meter from thecross-island trail in primary forest on Pulau Tioman.
Adult Dibamus tiomanensis displayed a behavior
most likely intended to ward off a predator. Whenpicked up or startled, the body scales flare up at an angle
almost perpendicular to the body. When viewed, thesmooth surface appears rugose, resembling the bristlecovered epidermis of an earthworm. It is possible that anon-palatable species of worm exists in the same areaand has served as a model for D. tiomanensis to mimic.
Darevsky (1992) mentions that D. greeri has bright blue
rings on its body, perhaps mimicking a megascolicid
worm inhabiting the same leaf litter. Such mimicking
behavior was also recently reported in D. booliati (Dasand Yaakob, 2003).

Acknowledgments
We thank Mr. Sahir bin Othman, Director of Wildlife,
Perhilitan, for permission to conduct fieldwork in theSeribuat Archipelago and Peter Ng, Chang Man Tangand Kelvin Kok Peng Lim for the loan of specimens. We

2004

also thank Allen Greer and Ted Papenfuss for reviewing
the manuscript. We especially thank Indraneil Das forhis significant contribution to the manuscript and forproviding sacral counts. We would also like to thank all
the students of Tropical Field Biology 487e from La
Sierra University who provided field assistance, andKaren Klitz for her help with Fig. 2.

Literature Cited
Bullock, J. A. and L. Medway. 1966. Observations on
the Fauna of Pulau Tioman and Pulau Tulai:
General Introduction. Bulletin of the National
Museum, Republic of Singapore. No. 34, March1966.
Darevsky, I. S. 1992. Two new species of worm-likelizard Dibamus (Sauria: Dibamidae) with remarkson the distribution and ecology of Dibamus inVietnam. Asiatic Herpetological Research 4:1-12Das, I. 1996. The validity of Dibamus nicobaricum(Fitzinger in Steindaehner, 1867) (Squamata:Sauria: Dibamidae). Russian Journal of
Herpetology3(2):157-162
Das, I. and K. K. P. Lim. 2003. Two new species ofDibamus (Squamata: Dibamidae) from Borneo.
Raffles Bulletin of Zoology 51(1):137-141.
Das, I. and N. Yaakob. 2003. A new species of Dibamus(Squamata: Dibamidae) from Peninsular Malaysia.
Raffles Bulletin of Zoology 51(1):143-147
Greer, A. E. 1985. The relationships of the lizard genera Anelytropsis and Dibamus.
Journal of
Herpetology19:116-156.
Honda, M. and J. Nabhitabhata, H. Ota., T. Hikida.
1997. A new species of Dibamus (Squamata:Dibamidae) from Thailand. Raffles Bulletin ofZoology 45(2):275-279
Honda, M., H. Ota, T. Hikida, and I. S. Darevsky 2001.
A new species of the worm-like lizard, DibamusDuméril & Bibron 1839 (Squamata Dibamidae),from Vietnam. Tropical Zoology 14:119-125.
Ineich, I. 1999. Une nouvelle espèce de Dibamus(Reptilia: Squamata: Dibamidae) du Vietnam.
Bulletin de la Société zoologique de France 124(3):279-286

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Asiatic Herpetological ResearchLim, K. P and L. J. Lim. 1999. The terrestrial herpetofauna of Pulau Tioman, Peninsular Malaysia.
Raffles Bulletin of Zoology 6:131-155.
Manthey, U. and W. Grossmann. 1997. Amphibien &Reptilien Südostasiens. NTV Verlag, Münster, 512pp.
Taylor, E. H. 1962. New oriental reptiles. University ofKansas Science Bulletin 44(14):687-1077
Taylor, E. H. 1963. The lizards of Thailand. Universityof Kansas Science Bulletin 44:687-1077.

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