Vol. 8, pp. 7-12

Asiatic Herpetological Research

1999

Description of a New Species of Pseudorabdion (Serpentes: Colubridae) fromPanay Island, Philippines with a Revised Key to the Genus

Rafe M. Brown

1'2,

Alan E. Leviton 3 and Rogelio V. Sison 4,

Section of Integrative Biology and Texas Memorial Museum, University of Texas, Austin, Texas, 78712(rafe@mail.utexas.edu); "Geier Collections and Research Center, Museum of Natural History and Science,
Cincinnati Museum Center. 1720 Gilbert Avenue, Cincinnati,OH 45202-1401: •Department of Herpetology,

California Academy of Sciences, San Francisco, CA 941 18 (leviton® sfsu.edu); 4 Zoology Department, Natiotud

Museum of the Philippines, Executive House, P. Burgos Street, Manila, Philippines (nmuseum@webciuest.com).
Abstract.- We describe a new species of snake in the colubrid genus Pseudorabdion from the western coastal

mountain range of Panay island, Philippines. The new species appears to be related to the members of the P.
species group (P. mcnamarae and P. taylori from the Philippines, P. albonuchalis, and P.
saravacensis from Borneo, and P. sarasinorum from Sulawesi) but differs from each of these species bymcnamarae

characters of scalation and color pattern. The new species is one of several other recently-discovered vertebrates

from Panay island. Together, these discoveries suggest that diversity and endemism patterns of the Negros-Panay
Pleistocene aggregate island platform (Negros, Panay,
interesting than previously thought.

Cebu and Masbate

Introduction

Paratype:CMNH

more complex andislands) are5076(Fieldno.

PNM/CMNH670), young male, other data as for holotype except it

While engaged in a biological reconnaissance surveyof the western coastal mountain range of Panay Island(Fig.

what1),

the senior author collected two specimens ofappeared

atthetimetobe Pseudorabdion

mcnamarae, a species already well know from Negros
Island. On closer examination it was discovered that
thePanay specimens differed in significant details
from the Negros population while sharing features

known from Mindanao, and with P.
albonuchalis, a species earlier known only from thewithP.

taylori,

was collected at 1410 m.

Etymology: The specific epithet is chosen from theAntique Province dialect Caray-a, and is derived fromthe words, "talon" (forest) and "uran" (rain), in refer-ence to the high elevation rain forest habitat where thenew species was collected on Mt. Madja-as.
Diagnosis: Elongate

loreal(=Iori-ocular)present,

extending from the posterior border of the nasal to thefrom Sarawak, Borneo. The observed differencesof the eye; ventrals (M) 139-146; subcaudals(M) 36-39; total of ventrals plus subcaudals (M) 175185; scales of dorsum each edged with a mottling ofbrown pigment, the posterior and central portions ofamong these related species leads us to believe thateach scale pale, lacking a dense infusion of dark pig-

thement, the lateral and latero-ventral scales with larger

type specimen (but see Inger and Leviton, 1966),
which can no longer be located, and said to have comeorbit

Panay specimens represent a previously unrecognized, taxonomically distinct population of Pseudo-

pale areas than those on

rabdiongenus

nuchal collar but pattern of pale centers and dark rims

Pseudorabdion whose members possess an elongatecharacterizes nuchal scales and head shields, which

loreal (lori-ocular) that borders the orbit anteriorly.

are somewhat mottled dark and light.

alliedtothesection

ofthePseudorabdion talonuran new spe-

thedorsum; nodistinct

Pseudorabdion talonuran belongs to the section of thegenus Pseudorabdion characterized by the presence

cies (Figs. 2-3)

of a loreal (lori- ocular) shield. From the allied Philip-

Holotype: PNM 2712 (Field no. PNM/CMNH 671),
adult male, collected on western foothills of Mt.

pine P. mcnamarae, it differs in lacking a pale nuchal
color in adults and in having more than 30 subcaudals

Madja-as (11°23' N, 122°09' E; elev. 1500 m), Baran-gay Allojipan, Municipality of Culasi, Antique Province, Panay Island, Philippines, 28 May 1992 by Rafe

Brown and Roger Sison.

in both males and females;from P. taylori it differs inhaving the centers and apical tips of the dorsal scales
nearly pigmentless whereas inP.

taylori the centers

are pale brown, and in having the hemipenes minutelyThis paper represents contribution number 23 to the results of the National Museum of the Philippines/
Cincinnati Museum of Natural History Philippine Biodiversity Inventors- (PNM/CMNH PB1)

Asiatic Herpetological ResearchVol. 8, p. 8

spinose (inP.

taylori the apical tips are calyculate).

Among the non-Philippine species having a lori-ocular, P.

talonuran differs from P. sarasinorum in having

the anterior chin shields in contact with the mental,

1999

frontal two-thirds length of parietals, subtriangular,
three-fourths as wide as long, in contact with prefron-supraocular and parietals, but not bordering eye;supraocular distinct, not fused to ocular brill; maxitals,

from P. albonuchalis in having fewer subcaudals (36-mum length of parietals slightly greater than distance

39 vs. 43) and the frontal not border the eye, and fromto tip of snout; nasal quadrangular, undivided, resting

P. saravacensis in having a greater number of subcaudals (36-39 vs. fewer than 30) and fewer maxillaryon first and in contact with second supralabials, nostril

teeth (8 vs. 14).

From the remaining species in thegenus, it differs in having an elongate loreal (lori-ocular) shield that borders the eye.

Description of holotype: (Adultmale) Rostral asvisible
fromabove slightly
aswide, portion
highofinternasal
internasals
thansuture;
greaterlengthsmall, greatest length about one-half greatest length ofprefrontals, in contact with rostral, nasal, loreal

andprefrontal: common suture between prefrontals aboutfour-fifths length of frontal: prefrontal bordering eye

between loreal and supraocular, also in contact withinternasals; left prefrontal in contact with both inter-nasals (because internasal suture offset from midline):pierced in anterior lower quadrant; loreal elongate,resting on second and third supralabials. about twice
as long as its distance to tip of snout, bordering eye;

preocular absent (or more likely fused to form anelongate loreal [lori-ocular]); postocular, subquadrangular, about one half size of supraocular, in contact
with fourth and fifth supralabials, not as high as eye,itslower border extending below level of eye andinserting between two supralabials; eye small, its
diameter equal to its distance from mouth, pupil
round; five supralabials and one large postsupralabial,

supralabials three and four border eye, fifth largest

and broadly
third,

in contact

with parietals, followed bysecond, fourth, and first in descending order of0-150]-12150-400]

400-800
800-1200
1200-1600

>1600

-11°

40 km

Borneo'^'"121°124°

Fig. 1 Map of Panay Island, showing its position in the Philippines (inset), major cities (darkened circles), provinces(dashed lines; names underlined) and elevational topography (see key). The type locality (Mt. Madja-as) of Pseudorabdion talonuran is indicated with a star.
.

1999

Asiatic Herpetological ResearchVol. 8, p. 9

posterior edge of parietals) 9.1mm; diameter of eye

0.8 mm.

Color pattern (in alcohol): Dorsal scales each withirregular dark borders; apical end and centers pale,nearly pigmentless, pigmentless areas larger and more
distinct laterally; ventrals unpigmented except for lateral edges; no nuchal collar.

Paratype: The paratype, a young male, differs fromthe holotype in the following particulars: ventrals 139;

subcaudals 36; snout-vent length, 265 mm; tail length
47 mm; apical ends of hemipenes do not appear to be
spinose (but the everted organ is poorly preserved anddifficult to examine).

Ecological notes: The forest habitat of the new speMadja-as (Fig. 4) has been classified bycies on Mt.

Whitmore (1984) as the transition zone between
mixed dipterocarp (submontane) and mossy (uppermontane) forests. The forest consists of two strata, aone large "posterior temporal" between postla-

canopy of 10 m and subcanopy of 3-4 m with emergent trees as high as 18 m; an herb and shrub layer
vegetation was also present. The forest near the col-bial and parietal; mental in contact with elongate ante-lection site was mossy and contained high densities ofrior chin shields; infralabials five, first three in contact

epiphytic

with anterior chin shields, third and fourth bordering

qualitatively characterized as steep, with numerous
sheer rocky valleys and forest-covered ridges (seeFig. 2. Dorsal (A) and lateral (B) views of head of holo-

type of Pseudorabdion talonuran.
size;

posterior chin shields; posterior chin shields about

three-fourths length of anterior pair, separated fromone another in the midline for two-thirds their lengthferns

and orchids. The topography was

Ferner, et al., 1997 for more details.) Both holotypeand paratype were found beneath logs.

by insertion of a gular scale, and about same size as

Remarks: The section of the genus Pseudorabdion

bordering gular scales; maxillary teeth eight.

characterized by the presence of an elongate loreal(lori-ocular) that borders the orbit, termed here theScales smooth, without apical pits, in 15 longitudinal rows, not reducing posteriorly before vent; ventrals

146mm;

subcaudals

39mm,paired;anal"mcnamarae" section, includes three species in thePhilippines, P.

Hemipenes extend in situ to 8th subcaudal plate,forked at the level of the 6th plate; apical ends withandP.

saravacensis from Sarawak, andP.

sarasi-norwn from Gunung (Volcano) Soudara, Sulawesi.
Five species (P. longiceps, P. ater, P. oxycephalum,minute spines.
Total length 265 mm; tail 46 mm; head length (tipof snout to angle of jaws) 1 1.25 mm, (tip of snout toP. eiselti,and P. montcmum) lack the loreal (lori-ocu-lar); the prefrontals are in contact with the second andthirdFig. 3. Dorsal view of holotype

mcnamarae, P. taylori, and P. talonu-ran, and three non-Philippine species, P. albonuchalis

undivided.

upper(PNM 2712) of Pseudorabdion talonuran.

labials.

Of the forms lacking a distinct

1999

Asiatic Herpetological ResearchVol. 8, p. 10

Fig. 4.Cloud forest habitat of Pseudorabdion

talonuran at the type locality: Mt. Madja-as, Antique Province, Panay

Island, Philippines.

loreal (or if a small scale is present in the loreal posi-that its high elevationmontane regions warrant moreneitherintensive biodiversity survey efforts in the near future.

elongate nor does it border the orbit), P. oxycephalum,P. ater, and P montanum are confined to the Philip-

Key tO the Species of Pseudorabdion

pines, f! me/ft is known only from the type locality
Padang, Sumatra, and P. longipes has been collected(Modified from Inger and Leviton, 1966)

tion, a rare occurrence among this group,

it isatat many localities on the islands of Borneo, Sulawesi,

Nias, and Sumatra, from Singapore and elsewhere
north along the Malay Peninsula, from the Riau

(Riou) Archipelago, and as far north as Ban Gnara andPatani, in southern Thailand.

The presence of this new, endemic

species ofsnake in the coastal mountains of western Panay
island further bolsters our suspicion that the level ot

endemism on

Panayisthani aLori-ocular (loreal) shield absent (if present, does
not border orbit); prefrontal in contact with upper2
labials^ Lori ocular shidd presem very.

distincti elongate
borders orbit; preftontal not in contact WIth upp er
7
labials,^ Preocular present; supraocular present; internasal^fa^^ ^

upper labia , s; maxillary teeth.
,,

previouslyp longipes

thought. By virtue of the fact that Panay was intermittently connected to Negros and Cebu at various points

2b. Preocular absent; supraocular present or absent;

during the Pleistocene (Heaney, 1986), biogeographers have justifiably expected that these islands tolabial^

greaterpossess a high percentage of faunal elements in common (Leviton. 1963; Brown and Alcala, 1970). Nevertheless,recentendemic

todiscoveriesofothervertebrates

Panay (Gonzales and Kennedy,1990,1996; Brown et al.. 1997; Ferner et al., 1997) suggest

internasals almost always in contact with upper3a.

Supraocular absent; frontal bordersorbit; nasal

4divided; maxillary teeth 10 or more

3^ Supraocular present; frontal does not border orbit;
5nasa undivided; maxillary teeth 10 or less]^ Postocular absent; masmsay teeth 10P.

ater

Asiatic Herpetological Research

1999

4b. Poslocular present; maxillary teeth 22-25

P.

P. collaris

Gonzales (PNM), R. Kennedy

provincial

P. eiselti

5b. Postocular and supraocular fused; ventrals greater

6than 140; suhcaudals greater than 15

6a. Each scale of outer row with dark centers and pale

brown except for
extreme posterior outer edges which are pale; ocularshield usually fused to combined supra- and postocuborders; ventrals uniformly darklars; suhcaudals (M) 22-24, (F) 16-17
P. oxycephalum

6b. Each scale of outer row with pale centers: ventrals

whitish with dark brown

more or less confined to abroad median band; ocular shield not fused to combined supra- and postoculars; suhcaudals (M) 28; (F)

21-24

P.

montanum

7a. Anterior chin shields not in contact with mental:

nasal shield divided

P. sarasinorum7b. Anterior chin shields in contact with mental; nasal

shield not divided

88a. Maxillary teeth greater than 1598b. Maxillary teeth fewer than 10109a. Ventrals greater than 125; suhcaudals greater than40(CMNH) and theDENR authorities of Antique Province.

For the loans of specimens, we thank the follow-5a. Postocular not fused to supraocular: ventrals 130;suhcaudals 12Vol. 8, p. 1 1

individuals

ingandtheirrespectiveinstitutions(museum acronyms, with the exception of CMNH.
follow Leviton et al., 1985): J. Vindum and R. Drewes(CAS), R. Kennedy and J. Ferner (CMNH), and P.
Gonzales (PNM). Financial support for RMB's traveltoCAS was provided by the C. Stearns Fellowship of

the California Academy of Sciences. We thank J. Bar-celona (PNM) for assistance with the Caray-a derivation of the new species name.

Support for RMB's field work was provided by theSociety for the Study of Amphibians and Reptiles, theRoschman Student Enrichment fund of the College ofArts andSciences, and the Zoology and Botany
Departments of Miami University (Oxford, Ohio).

The PNM/CMNH PBI was supported by a grant (to R.
Kennedy andP.

Gonzales) from the John

D andCatherine T. MacArthur Foundation and by the benefactors of Cincinnati Museum of Natural History.

We thank D. Cannatella and A. Diesmos for comments on earlier drafts of this manuscript.

Literature Cited

albonuchalis

Brown, W. C. and A. C. Alcala. 1970. The zoogeogra-9b. Ventrals fewer than 120; suhcaudals fewer than 30

phy of the Philippine Islands, a fringing archipelago.

P.

P. saravacensis

Proc. California Acad. Sci. 38:105-130.

10a. Pale nuchal collar usually present; suhcaudals

Brown, W. C, R. M. Brown, and A. C. Alcala. 1997.

7-30; distal portion of hemipenes minutely spinose

Species

1P.

menamarae

10b. Pale nuchal collar absent in adults; suhcaudals

greater than 30

11Dorsal scales uniform pale brown, each scale
thinly edged with pigmentless border; distal portionI

la.

of hemipenes calyculate

P. tayloriof(Amphibia:

thehazelae

Ranidae)descriptions of two

group

newof

thePlatymantis
Philippines, withspecies.

Proc. California

fromAcad. Sci. 49:405-421, Figs. 1-4.
Ferner, J. W., R. M. Brown, and A. E. Greer. 1997. A

new genus and species of moist closed canopy forest
skinks from the Philippines. Jour. Herpetol. 31:187192, Figs. 1-3.

1lb.

Dorsal scales with pale, nearly pigmentless cen-ters and apical tips, anterior borders of each scale withbrown mottling, larger areas of latero-ventral scalesdevoid of dark pigment; hemipenes minutely spinose
P. talonuran

Gonzales, PC. and R.S. Kennedy. 1990. A new species of Stachyris babbler ( Aves: Timaliidae). from theisland of Panay, Philippines.

Wilson Bull. 102: 367-379.

Gonzales, PC. and R.S. Kennedy. 1996. A new spe-Acknowledgments
We thank The Protected Areas and Wildlife Bureau(PAWB) of the Philippines Department of the Environment and Natural Resources (DENR) for facilitating collecting and export permits necessary for thefield work that contributed to this study. For logisticalcies of Crateromys (Rodentia: Muridae)

Philippines.

J.

from Panay,

Mamm. 77:25-40.

Heaney, L. R. 1986. Biogeography of small mammals
in SE Asia: estimates of rates of colonization, extinction and speciation. Biol. Jour. Linnaen Soc, London

28:127-165, Figs. 1-8.

A new colubrid

assistance in the Philippines, we thank Corazon Cati-Inger, R. F, and A. E. Leviton. 1961.

bog-Sinha (DENR), A. Alcala (Silliman University),snake of the genus Pseudorabdion from Sumatra.
Fieldiana: Zoology 44:45-47, Fig. 1.

Asiatic Herpetological ResearchVol. 8, p. 12

1999

mcnamarae:

Inger, R. F., and A. E. Leviton. 1966. The taxonomic

Pseudorabdion

status of Bornean snakes of the genus Pseudorabdion

Negros Island: Negros Occidental Prov.:

Jan and of the nominal genus Idiopholis Mocquard.
Proc. California Acad. Sci., 34:307-314, Figs. 1-3.

-Leviton, A. E., and W. C. Brown. 1959.

A review ofthe genus Pseudorabdion with remarks on the status

Philippine

Islands:CAS 185577

Panakiyo, 22 km E Isabela, 16 April 1960 by Q. andCAS 186052 - Cuer-L. Alcala. Negros Oriental Prov.:

nos de Negros. 3600-3800 ft., 24 December 1959 byQ. Alcala and R. Empeso.
talonuran: See Holotype and Paratype sections forof the genera Agrophis and Typhlogeophis (Serpentes:P.

Colubridae). Proc. California Acad. Sci., 29:475-508,

this species.

Figs. 1-10.

P.

Leviton, A. E. 1963. Remarks on the zoogeography ofsion): CAS 101500 - Niah, Tangap, 6 December 1960

Philippine terrestrial snakes. Proc. California Acad.

by T. Harrison.

Sci. 31:369-416, Fig.

P.

1.

albonuchalis:

Malaysia:

Sarawak (Fourth Divi-Leviton, A. E., R. H. Gibbs, Jr., E. Heal, and C. E.

oxyeephalum Philippine Islands: Panay Island:
Aklan Prov.: CAS 137643 - Nabas, Laserna Barrio, 12Dawson. 1985. Standards in herpetology and ichthy-May 1973 by L. Alcala. Negros Island: Negros Occi-ology: Part I. Standard symbolic code for institutional

dental Prov.:

resource collections in herpetology and ichthyology.

barrios Alim and Asia, 9-10 June 1967 by L. Alcala

Copeia 1985: 802-832.

and party: Barrio Asia, 30 May-3 June 1967 by A.
Alcala, L. Pelingon and F Pelingon. Negros Oriental

Appendix 1. Specimens Examined
In addition to specimens listed in earlier publications

by Leviton and Brown 1959) and by Inger and Leviton (1961 and 1966), the following new materials
have been examined:(Prov.:CASCAS 185453-185457

110974--Hinoba-an Town,

Camp Lookout. Valencia, 14NWofJune 1967 by L. and F. Pelingon: 24-25 km
Bondo [about 10 km N of Siaton], 27-31 December

1958 by A. Alcala and party.