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A Taxonomic Revision of the Philautus (Anura: Rhacophoridae) of Sumatra with the Description of Four New Species

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  • Museum Zoologicum Bogoriense, Research Center for Biology, Indonesian Institute of Sciences

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This paper is the first taxonomic treatment of Sumatran Philautus since the early 20th century. We redescribe P. cornutus and P. petersi from new specimens, restrict P. petersi to Great Natuna Island, and reinstate the name P. larutensis for the populations on Borneo, Peninsular Malaysia, and Sumatra. We then synonymize P. similis with P. larutensis. We report Sumatran populations of P. kerangae and P. refugii, two species previously thought to be endemic to Borneo and discuss the presence of P. aurifasciatus on the island. We describe four new species of Philautus collected during large-scale herpetological surveys of Sumatra between 2013 and 2015 and propose a hypothesis of their relationship to the other Sunda Shelf Philautus on the basis of 16S ribosomal ribonucleic acid sequences. Additionally, we provide a key to the Philautus of Sumatra. In the course of this work we transfer P. vittiger from Java to the genus Chiromantis.
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A Taxonomic Revision of the Philautus (Anura: Rhacophoridae) of Sumatra with
the Description of Four New Species
Author(s): Elijah Wostl, Awal Riyanto, Amir Hamidy, Nia Kurniawan, Eric N. Smith, and Michael B.
Harvey
Source: Herpetological Monographs, 31(1):70-113.
Published By: The Herpetologists' League
https://doi.org/10.1655/HERPMONOGRAPHS-D-16-00007
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Herpetological Monographs, 31, 2017, 70–113
Ó2017 by The Herpetologists’ League, Inc.
A Taxonomic Revision of the Philautus (Anura: Rhacophoridae) of Sumatra with the
Description of Four New Species
ELIJAH WOSTL
1,5
,AWAL RIYANTO
2
,AMIR HAMIDY
2
,NIA KURNIAWAN
3
,ERIC N. SMITH
1
,AND MICHAEL B. HARVEY
4
1
Amphibian and Reptile Diversity Research Center and Department of Biology, University of Texas at Arlington, Arlington, TX 76019, USA
2
Laboratory of Herpetology, Museum Zoologicum Bogoriense, Research Center for Biology, Indonesian Institute of Sciences–LIPI, Widyasatwa Loka Jl.
Raya Jakarta Bogor km 46, Cibinong, West Java 16911, Indonesia
3
Department of Biology, Universitas Brawijaya, Jl. Veteran, Malang, East Java 65145, Indonesia
4
Department of Biological Sciences, Broward College, 3501 S.W. Davie Road; Davie, FL 33314, USA
ABSTRACT: This paper is the first taxonomic treatment of Sumatran Philautus since the early 20th century. We redescribe P. cornutus and P.
petersi from new specimens, restrict P. petersi to Great Natuna Island, and reinstate the name P. larutensis for the populations on Borneo,
Peninsular Malaysia, and Sumatra. We then synonymize P. similis with P. larutensis. We report Sumatran populations of P. kerangae and P.
refugii, two species previously thought to be endemic to Borneo and discuss the presence of P. aurifasciatus on the island. We describe four new
species of Philautus collected during large-scale herpetological surveys of Sumatra between 2013 and 2015 and propose a hypothesis of their
relationship to the other Sunda Shelf Philautus on the basis of 16S ribosomal ribonucleic acid sequences. Additionally, we provide a key to the
Philautus of Sumatra. In the course of this work we transfer P. vittiger from Java to the genus Chiromantis.
Key words: Anuran taxonomy; Biodiversity; Biogeography; Sunda Shelf
THE SUNDA Shelf has long been recognized for its
biodiversity and is one of Earth’s biodiversity hot spots
(Myers et al. 2000). The islands Borneo, Java, and Sumatra,
along with the Malaysian Peninsula, compose the majority of
the subaerial land of the present-day Sunda Shelf. The
current distribution of land and sea, however, is relatively
young. The various land masses have repeatedly merged and
divided in response to tectonic activity and changes in sea
level (Hall 1998, 2013; Voris 2000). The current configuation
was not reached until the Holocene (Solihuddin 2014).
Similarly, the distribution of perhumid rain forests under-
went drastic changes in response to climatic fluctuations
(Cannon 2012; Morley 2012). The temporally shifting
distribution of land, sea, and forest has been implicated in
shaping the patterns of phylogenetic relationships within
several groups of organisms that occur on the Sunda Shelf,
including freshwater fish (Dodson et al. 1995), frogs and
snakes (Inger and Voris 2001), squirrels (Mercer and Roth
2003), murine rodents (Gorog et al. 2004), and primates
(Harrison et al. 2006); making it clear that taxonomic,
systematic, and phylogenetic work conducted in the region
should strive to include as many of the relevant land masses
as possible.
The genus Philautus Gistel 1848 is traditionally defined as
small rhacophorid frogs that lack vomerine teeth (Van
Kampen 1923; Inger 1954, 1966) and an aquatic tadpole
stage (Bossuyt and Dubois 2001). Historically, three
subgenera and 177 species have been assigned to the genus
(Bossuyt and Dubois 2001). Through a series of previous
taxonomic reorganizations based on molecular data (Frost et
al. 2006; Li et al. 2008, 2009; Yu et al. 2008, 2009), that
number has dwindled to 52 currently recognized species.
Additionally, the description of species that possess vomer-
ine teeth (Dring 1987; Inger et al. 1995) and the reallocation
of species with either vomerine teeth or a tadpole stage to
the genus (Liem 1970; Hertwig et al. 2012a) have left the
genus without a morphological synapomorphy. Species are
currently allocated to the genus on the basis of morpholog-
ical and genetic similarity to already-described species
(Dehling and Dehling 2013; Dehling et al. 2016).
The genus occurs across southern Asia from eastern India
to the Philippines and reaches its highest diversity on the
Sunda Shelf (Frost 2016). However, the knowledge of the
diversity of the genus on the Sunda Shelf is strongly skewed
toward regions with a long history of biological exploration.
Of the 28 species known to occur in the region, 17 are known
only from Malaysian Borneo and 9 of these are known only
from in and around three well-studied national parks:
Gunung Kinabalu, Gunung Mulu, and Kubah (Frost 2016).
In comparison, just 3 species are known from Kalimantan,
though it makes up more than 70% of Borneo.
Sumatra is similarly underrepresented. Currently, just
three species of Philautus are thought to occur on the island:
P. aurifasciatus (Schlegel 1837), P. cornutus (Boulenger
1920), and P. similis Van Kampen 1923. Philautus cornutus
and P. similis are known only from the type specimens and
our experience leads us to doubt the occurrence of P.
aurifasciatus ontheisland.Themostrecentworkto
incorporate species and specimens of Philautus from
Sumatra was that of Van Kampen (1923). Since then, work
on the genus in the region has focused on Malaysian Borneo
presumably for want of specimens (Smith 1931; Inger 1966,
1989; Dring 1987; Inger et al. 1995; Inger and Stuebing
1996; Malkmus and Riede 1996a,b; Stuebing and Wong
2000; Dehling 2010; Dehling and Dehling 2013; Dehling et
al. 2016). Although unavoidable, the exclusion of specimens
from the other major regions of the Sunda Shelf has
undoubtedly influenced the perception of diversity in the
genus.
Our work on the island of Sumatra has revealed several
new species of Philautus, described herein. We also provide
updated descriptions and diagnoses of the species known to
occur on the island on the basis of recently collected
5
CORRESPONDENCE: e-mail, ewostl@uta.edu
70
specimens. For completeness, we include P. petersi and its
subjective synonym P. larutensis, names never applied to
Sumatran Philautus, in this discussion because the status of
these taxa has a direct impact on the taxonomic status of P.
similis.
MATERIALS AND METHODS
Taxon Sampling
We collected most specimens used in this study during
herpetological surveys of Java and Sumatra between June
2013 and August 2015. At the time of collection, we recorded
the latitude, longitude, and elevation using a handheld global
positioning system device (GarmintGPSMAP 64s) with the
datum set to WGS84.We fixed specimens in 10% formalin
and transferred them to 70% ethanol for preservation.
Before preservation, we photographed the dorsal, lateral,
and ventral aspects of each specimen and took a tissue
sample from the thigh or liver for further molecular work.
We also photographed a subset of each species in life before
euthanasia. All specimens are deposited at the Amphibian
and Reptile Diversity Research Center at the University of
Texas, Arlington (UTA) or at the Laboratory of Herpetology,
Museum Zoologicum Bogoriense (MZB), Cibinong, Indo-
nesia. Museum acronyms used in this paper follow Sabaj
(2016) except University of Michigan Museum of Zoology
Field Series (UMFS). Several of the sequences from
GenBank are not associated with recognizable institutional
acronyms (accession numbers KX440525, KC465827, and
KF053220). LJT 73 and HN 0806039 represent field
numbers (Jia-tang Li, personal communication) and we
suspect that ‘‘712’’ and BH 79 do as well.
Morphology
We examined 195 specimens of adult Philautus from
Sumatra, 21 P. aurifasciatus from Java, and 7 adult P. petersi
from Great Natuna Island. We also examined the holotypes
of P. similis,P. jacobsoni,andP. vittiger along with
photographs of the type specimens of P. cornutus and the
syntypes of P. petersi from Great Natuna Island.
We collected mensural data from 13 morphological traits:
snout–vent length (SVL, from tip of snout to vent with
specimen held flat), head length (HL, straight line distance
from posterior margin of mandible to tip of snout), head
width (HW, width of head at rictus), internarial distance
(IND, straight line distance between medial border of
nares), eye–naris distance (EN, straight-line distance from
anterior margin of bony orbit to posterior margin of naris),
eye–snout length (straight line distance from anterior margin
of bony orbit to tip of snout), interocular distance (IOD,
width of narrowest point of bony cranium between eyes),
forearm length (FaL, from proximal end of elbow when
flexed to proximal edge of palmar tubercle), hand length
(HnL, proximal margin of palmar tubercle to tip of third
finger), thigh length (ThL, vent to distal margin of femur
with thigh perpendicular to body), crus length (CrL,
proximal end of tibiofibula to outer margin of heel with leg
bent), tarsus length (TarL, from heel to proximal margin of
inner metatarsal tubercle), and foot length (FL, from
proximal margin of inner metatarsal tubercle to tip of fourth
toe). We did not measure several characters (eye width,
toepad width, eyelid width, tympanum width, tympanum–
eye distance) often used in the description of Philautus
species (Van Kampen 1923; Inger 1966; Dring 1987; Inger
1989; Inger and Stuebing 1996; Stuebing and Wong 2000;
Bossuyt and Dubois 2001; Matsui 2009; Dehling 2010;
Dehling and Dehling 2013). We found that preservation
artifacts rendered these characters of little comparative
value. We measured characters to the nearest 0.01 mm with
digital calipers, usually with the aid of a stereo dissecting
microscope or with an ocular micrometer with 200 divisions
per centimeter. We used the program IMAGE J (Schneider
et al. 2012) to take a small set of measurements from the
photographs of type specimen of P. cornutus and P. petersi.
In addition to mensural data, we also took data on 56
qualitative morphological characters from each specimen. A
few of our qualitative characters require further comment
here. The dermal tubercles were always more evident in life
than in preserved specimens. When possible, we derived the
description of tubercles from live specimens, their photo-
graphs, or photographs taken immediately postmortem. We
assessed sex and maturity by making an incision in the flank
and examining the gonads. We noted presence or absence of
the m. cutaneous pectoris and the state of the pectoral
septum by carefully reflecting skin that overlies the pectoral
region. This process is somewhat destructive and these
characters were only examined in a subset of each species.
The webbing formulae follow that of Savage and Heyer
(1967) as modified by Myers and Duellman (1982). Our
terminology for toepads, dorsal tubercles, and descriptions of
snout shape follows Savage (1987, 2002). For clarity, the
proximal subarticular tubercle is at the phalangeal–metacar-
pal or phalangeal–metatarsal articulation. We define super-
numerary tubercles as tubercles on the ventral surface of the
digits, distal to the proximal subarticular tubercle and not
directly ventral to an articulation. All morphological data
were collected by a single observer (EW).
Our data were compared with published data for the
currently recognized species of Philautus on the Sunda
Shelf: P. acutus Dring 1987; P. amoenus Smith 1931; P.
aurantium Inger 1989; P. aurifasciatus (Schlegel 1837); P.
bunitus Inger, Stuebing, and Tan 1995; P. cornutus
(Boulenger 1920); P. davidlabangi Matsui 2009; P. disgregus
Inger 1989; P. erythrophthalmus Stuebing and Wong 2000;
P. gunungensis Malkmus and Riede 1996a; P. hosii
(Boulenger 1895); P. ingeri Dring 1987; P. jacobsoni (Van
Kampen 1912); P. juliandringi (Dehling 2010); P. kakipan-
jang Dehling and Dehling 2013; P. kerangae Dring 1987; P.
macroscelis (Boulenger 1896); P. mjobergi Smith 1925; P.
nephophilus Dehling, Matsui, and Imbun 2016; P. pallidipes
(Barbour 1908); P. petersi (Boulenger 1900a); P. refugii
Inger and Stuebing 1996; P. saueri Malkmus and Riede
1996a; P. similis Van Kampen 1923; P. tectus Dring 1987; P.
umbra Dring 1987; P. vermiculatus (Boulenger 1900b); and
P. vittiger (Boulenger 1897). We also utilized information
contained within these descriptions about nonfocal Philautus
species and other publications (Manthey and Grossman
1997; Malkmus et al. 2002; Bossuyt and Dubois 2001) to
form our diagnoses.
Our examination of the holotype of P. similis raised
questions about the distinctiveness of this taxon. To test its
taxonomic placement, we conducted a principal component
analysis (PCA) to reduce our morphological data set of adult
female Philautus,(n¼79: 1 P. amabilis,3P. cornutus,11P.
71
WOSTL ET AL.—SUMATRAN PHILAUTUS
larutensis,14P. ventrimaculatus,2P. petersi,26P.
polymorphus,3P. refugii,1P. similis,18P. thamyridion)
into independent components. To do so we first log
10
transformed our mensural data and regressed them against a
log
10
-transformed SVL. We used the resulting residuals in
the PCA. This method effectively removes the influence of
body size on the analysis (Reist 1986). To determine the
number of principal components with statistically significant
eigenvalues (a¼0.05) we used a Monte Carlo simulation
following O’Connor (2000). The factor scores from the
components of the PCA with significant eigenvalues were
used to conduct a discriminant function analysis using
species as the grouping variable. All statistical analyses were
performed in IBM SPSStv23.0 (IBM Corp. Armonk, NY,
USA).
Vocalizations
When possible, we recorded advertisement calls from
Philautus as uncompressed .wav files at a 44.1-kHz sampling
rateand16-bitresolutionwithaZoomH4NHandy
Recorder using the built-in microphone. This resulted in a
small number of vocal recordings for P. larutensis and each
of the new species described herein. We used the program
Audacity v2.1.2 (Audacity Team 2016) to trim the recordings
to a manageable length and reduce background noise with
the noise-removal and notch-filter tools. We generated
spectrograms and oscillograms of the calls in Raven Lite
v1.0 (Charif et al. 2006). To determine the length of the
notes, pulses, internote period, and interpulse period as well
as calculating the fundamental and dominant frequencies,
we used the program SoundRuler v0.9.6.0 (Gridi-Papp
2007). The noise-reduction steps also remove evidence of
frequency modulation and were therefore applied conserva-
tively. For the purposes of this paper, we define a note as an
uninterrupted emission of sound. Peaks of amplitude
modulation within a note are referred to as pulses. A call is
an assemblage of notes or pulses.
Molecular Data
We amplified a fragment of the mitochondrial 16S
ribosomal ribonucleic acid coding gene for representative
specimens of each species using the primer pairs 16SA-L (50-
CGC CTG TTT ATC AAA AAC AT-30) and 16SB-H (50-
CCG CTC TGA ACT CAG ATC ACG-30; Vences et al.
2005) and LX12SN1 (50GAC CTG GAT TAC TCC GGT
TCT GAA CTC 30) and LX16S1R (50TAC ACA CCG CCC
GTC A 30; Zhang et al. 2013). The polymerase chain reaction
thermal cycling profile sets consisted of initial denaturation
at 958C followed by five cycles of a 30-s, 958C denaturation; a
30-s, 508C annealing; and a 2-min, 728C extension followed
by 40 similar cycles with the annealing temperature raised to
548C and then a final 10-min extension at 728C. Amplifica-
tion products were cleaned using ‘‘serapure’’ magnetic beads
(Rohland and Reich 2012). Cycle sequencing reactions in
both primer directions and Sanger sequencing were
performed using standard protocols associated with BigDyet
terminator chemistry (Applied Biosystems, Foster City, CA,
USA) at the UTA genomics core facility (Arlington, TX, USA;
http://gcf.uta.edu). We assembled and edited the raw
sequence chromatograms using the program Sequencher
v5.1 (Gene Codes Corporation Ann Arbor, MI, USA).
Phylogenetic Analysis
We aligned the sequences generated in this study with
sequences available on GenBank of other Sunda Shelf and
Philippine Philautus and representatives of all other
rhacophorid genera in the region: Chiromantis,Feihyla,
Gracixalus,Kurixalus,Liuixalus,Nyctixalus,Polypedates,
Rhacophorus, and Theloderma. We included a sequence of
Buergeria oxycephala to root the trees in phylogenetic
reconstructions. We constructed the initial alignments using
the program MUSCLE (Edgar 2004) implemented in
MEGA v6.0 (Tamura et al. 2013) and visually inspected
the resulting alignment, adjusting manually as needed.
To examine similarity between sequences we constructed
an uncorrected pairwise distance matrix in MEGA 6.0. We
conducted a maximum likelihood analysis using the RaxML
GUI (Silvestro and Michalak 2012) with the model of
molecular evolution set to GTRGAMMA and Buergeria
identified as the outgroup and estimated nodal support using
350 bootstrap replicates. The number of replicates was
determined using the automated bootstrap convergence test
‘‘autoMRE’’ implemented within the program. We used
MRBAYES v3.2 (Ronquist et al. 2012) to run four
independent Bayesian analyses, each with three heated
chains and one cold chain and sampling every 1000
generations for 15 million generations. We used the program
Tracer (Rambaut et al. 2014) to assess adequate mixing of
chains and the appropriate number of samples to discard as
burn-in and the program Are We There Yet (Wilgenbusch et
al. 2004) to check for the convergence of the independent
runs onto a single topology. Phylogenetic trees were
visualized in the program FigTree (Rambaut 2012).
The two primer sets used produced fragments of different
lengths. The fragments also differed in length from the
sequences available from GenBank. We trimmed sequences
to a length that maximized the number of base pairs while
ensuring that each base pair was represented by at least two-
thirds of the sequences. This resulted in an alignment of 834
base pairs. To check for the impact of the missing data on
tree topology and posterior support, we ran the Bayesian
analysis for both the alignment of 834 base pairs and a
shorter alignment of 442 base pairs in which we removed
most external sites that are missing data.
RESULTS
Morphology
Morphological data are sufficient to distinguish all
Sumatran Philautus from each other and from most other
Sunda Shelf species. We are unable to separate Sumatran
populations of P. larutensis from P. kakipanjang, and P.
polymorphus from P. vermiculatus on the bais of the
published descriptions of those species (Boulenger 1900b;
Dring 1987; Dehling and Dehling 2013). A thourough
examination of specimens of each is required to form a
morphological diagnosis.
Philautus petersi from Great Natuna Island and P.
cornutus are sufficiently distinct to allow us to match
contemporary specimens to the type material through an
examination of photographs. Key characters that allow the
match of P. cornutus include size, extremely reduced
webbing of the feet, relative length of the tibia, and presence
of an angular canthus and pointed projecting snout. The P.
72 Herpetological Monographs 31, 2017
petersi syntypes were matched to contemporary specimens
by size; tuberculation of the mandible, eyelid, and dorsum;
relative length of the crus; and locality.
Like species of Chiromantis, and unlike any Philautus,
theholotypeofP. vittiger (BMNH 1947.2.7.58) has fingers
I and II in opposition to fingers III and IV, finger I longer
than finger II, and metatarsals divided by webbing.
Additionally, the holotype of P. vittiger is small, atubercu-
late, has realtively extensive pedal webbing, and possesses a
spotted dorsum and light dorsolateral stripes, all of which
characterize other species of Chiromantis. On the basis of
these observations, we transfer Ixalus vittiger Boulenger
1897 to Chiromantis as Chiromantis vittiger (Boulenger)
comb. nov.
The PCA recovered three components with significant
eigenvalues. Together, these three components account for
78.3% of the total variation. IND, ThL, CrL, and TarL are
strongly and positively loaded onto the first principal
component; FaL, HnL, and FL onto the second. HL, snout
length (SnL), and EN are strongly but negatively loaded onto
the third component. Table 1 provides the loading scores of
each variable onto the first three principal components.
The discriminant function analysis correctly classified
70.9% of the original cases. Most of the errors in
classification were due to the incorrect classification of P.
ventrimaculatus as P. polymorphus. Additionally, the
analysis only classified one P. cornutus correctly; the
remainders were misclassified as P. thamyridion.Figure1
displays scatter plots of the factor scores of the first two
principal components from the PCA and discriminant
scores from the discriminant function analysis. In the
cross-validation of the discriminant function analysis, in
which each individual is assigned to a group on the basis of
the derived discriminant functions from all other individ-
uals, the holotype of P. similis was grouped with P.
larutensis with a probability of 0.602.
TABLE 1.—Loading scores of variables onto the first three principal
components.
Principal components
123
Crus length 0.951 0.03 0.07
Tarsus length 0.943 0.14 0.039
Thigh length 0.901 0.073 0.129
Internarial distance 0.842 0.135 0.03
Head length 0.192 0.001 0.882
Interocular distance 0.142 0.099 0.064
Forearm length 0.087 0.932 0.095
Eye–naris 0.079 0.045 0.841
Foot length 0.052 0.871 0.006
Snout length 0.066 0.061 0.842
Hand length 0.091 0.877 0.061
Head width 0.121 0.478 0.593
FIG. 1.—Scatter plots of the first two principal components showing the distribution of the species in size-corrected morphospace (A). Plot of the
discriminant scores and function and the centroids of each species (B).
73
WOSTL ET AL.—SUMATRAN PHILAUTUS
Vocalizations
The small number of recordings per species limits the
analysis of vocalization patterns. Moreover, the recordings of
P. thamyridion and P. polymorphus exceeded the capabil-
ities of our recorder and the extremes of the call were not
captured. This potentially compromises the analysis of vocal
characteristics. However, the vocalizations of the Sumatran
Philautus are both distinctive and diagnostic and provide one
of the surest methods of identification. For this reason, we
provide descriptions of the call within the accounts for each
species when we can, even if based on a single individual or a
recording that does not cover the entire sound spectrum. We
do not have recordings of P. cornutus or P. refugii, nor have
we heard them vocalizing. Figure 2 depicts the oscillograms
of the call for each species, Fig. 3 provides sonograms of the
same recordings, and Fig. 4 depicts the oscillograms of a
single note from the call of each recorded species. The
unedited recordings of the vocalizations used in this paper
are available online through the Cornell Lab of Ornithology
Macaulay Library under catalog numbers 219800–219806.
Phylogenetic Relationships
The final alignment consisted of 70 sequences and
included representative sequences from all Philautus from
the Sunda Shelf except P. erythrophthalmus,P. gunungensis,
P. jacobsoni,P. pallidipes,andP. saueri. Genetic data and
tissues are not available for these taxa. The Bayesian analyses
of the short and long alignments yielded similar topologies.
The one difference was the placement of P. petersi from
Natuna Island outside of Philautus in the tree generated
from the short alignment. Additionally, the short alignment
did not support some of the nodes as well as the longer
alignment. We present the results from the analysis of the
longer alignment, which consisted of sequences between 474
and 834 base pairs in length and was 91% complete overall.
A list of sequences used in this study and their GenBank
accession numbers is provided in Table 2.
Both Bayesian and maximum likelihood analyses pro-
duced similar results; the only difference between the two is
in the relative placement of the deep unsupported nodes.
Philautus from the Sunda Shelf and Philippines form a
strongly supported monophyletic group exclusive of other
genera of Sunda Rhacophoridae. The deeper relationships
within Philautus are unresolved. These divisions represent
divergent lineages that will only be clarified with more
extensive genetic sampling. Within Sunda Shelf Philautus,
there are several strongly supported clades. The largest clade
is composed of P. acutirostris,P. amoenus,P. davidlabangi,
P. disgregus,P. juliandringi,P. kakipanjang,P. larutensis,P.
mjobergi,P. nephophilus,P. refugii,P. surdus,P. umbra, and
P. worcesteri. Within this clade, the Philippine species are
supported as monophyletic. Philautus larutensis from
Sumatra and the type locality in Peninsular Malaysia are
almost identical, leaving little doubt of the appropriate
allocation of Sumatra specimens to this species. They are
sister to P. cf. larutensis from Borneo, which may represent a
distinct species. We recover a strongly supported sister
relationship between P. amoenus and P. nephophilus. This
differs from the results of Dehling et al. (2016), who recover
a sister relationship between P. nephophilus and P. mjobergi,
its former synonym. That study, however, did not include P.
amoenus in the phylogenetic analysis. Philautus acutirostris
appears paraphyletic in our analysis. However, this arrange-
ment does not change the overall groupings and we have
retained the original identifications associated with the
sequences.
Other strongly supported clades include: a previously
unknown Sumatran radiation composed of P. amabilis,P.
cornutus,P. polymorphus,P. thamyridion, and P. ventrima-
culatus; a clade that includes P. abditus,P. acutus,P.
aurantium,P. bunitus,P. kerangae, and P. vermiculatus;a
clade composed of P. everetti and P. macroscelis; and a clade
composed of P. hosii and P. ingeri.
In addition to the subclades, P. aurifasciatus,P. petersi
from the type locality (Great Natuna Island), and P. tectus
are represented by deeply divergent monotypic lineages, the
specific relationships of which are unresolved. See Fig. 5 for
a visual representation of the relationships within this group.
The pairwise distance between P. refugii from Sumatra
and Borneo, P. larutensis from Peninsular Malaysia and
Sumatra, and P. kerangae from Sumatra and P. bunitus from
Borneo are minimal, suggesting that these represent
allopatric populations of the same species. Our resoning
for applying the name P. kerangae to the Sumatran specimen
is provided in the Discussion. Table 3 provides the pairwise
distance matrix of select Sunda Shelf Philautus.
The results of the phylogenetic analysis above are based
on a fragment of a single mitochondrial region. As such, they
are best treated as a preliminary, though informative,
hypothesis of the larger relationships of the Philautus of
the Sunda Shelf. It should be noted that where sampling
overlaps, our results do not differ from studies that
incorporate more loci from both nuclear and mitochondrial
regions of the genome (Hertwig et al. 2013).
SPECIES ACCOUNTS
The taxonomic descriptions below are divided into two
sections. The first provides updated descriptions of previ-
ously described species and the second provides descriptions
of novel taxa. In each, the section on morphological variation
is derived from the referred specimens and the type series
where applicable. Data are presented as the range of values
observed in males, then the range of values observed in
females. Each is followed by the mean 61SDin
parentheses. Characters that do not differ from the holotype
are not included. For the single specimen of P. kerangae,we
provide the measurements of the specimen. All measure-
ments are given in millimeters.
We have done our best to differentiate the Sumatran
species from all Philautus known to occur on the Sunda Shelf
excluding P. gunungensis and P. pallidipes. Philautus
gunungensis is very similar to P. aurantium morphologically
and is known only from high elevations on Mt. Kinabalu,
Sabah, Malaysia. The comparison of the species within this
paper to P. aurantium should apply at least in part to P.
gunungensis.Philautus pallidipes is known only from the
holotype, collected from ‘‘ near the summit of the volcano
Pangerango, Java’’ (Barbour 1908:190). This locality is now
part of Gede-Pangrango National Park and has been the
focus of multiple amphibian surveys since the original
description (Liem 1971; Kusrini et al. 2005; Kusrini 2007).
No additional specimens have been collected and Liem
74 Herpetological Monographs 31, 2017
FIG. 2.—Oscillograms of vocalizations from Sumatran Philautus. P. amabilis (A, MZB.Amph.26892, Gunung Marapi, Sumatera Barat, 198C), P. larutensis
(B, MZB.Amph.26866, vicinity of Takengon, Aceh, 178C), P. polymorphus (C, MZB.Amph.26789, Gunung Patah, Sumatera Selatan, 188C), P. thamyridion
(D, MZB.Amph.26763, Gunung Pesawaran. Lampung, 18.48C), and P. ventrimaculatus (E, UTA-A 63873, Gunung Patah, Sumatera Selatan, 188C). Note
that the scale differs between graphs. The individual notes in the red boxes are depicted in Fig. 5. A color version of this figure is available online.
75
WOSTL ET AL.—SUMATRAN PHILAUTUS
FIG. 3.—Sonograms of the vocalizations in Fig. 3. Philautus amabilis (A), P. larutensis (B), P. polymorphus (C), P. thamyridion (D), and P. ventrimaculatus
(E). Note that the scale differs between graphs. A color version of this figure is available online.
76 Herpetological Monographs 31, 2017
(1971) suggests that P. pallidipes may be a synonym of P.
aurifasciatus. Iskandar and Mumpuni (2004a) report on the
occurrence of additional specimens of P. pallidipes from
Gunung Halimun National Park, Java. However, specimens
at the MZB labeled P. pallidipes from that locality are a
species of Chiromantis.
It should be noted that our diagnoses from species that
are known only from Borneo and Peninsular Malaysia are
derived from previously published works and should be
considered critically. As a group, the genus tends to be
morphologically variable. Additionally, it is an almost
certainty that characters are interpreted and measured
differently by different observers.
Previously Described Species
Philautus cornutus (Boulenger 1920)
Figs. 6, 14–17, 19
Ixalus cornutus Boulenger 1920:295, ‘‘ several specimens
from Sungei Kring, 7300 feet. Korinchi Peak’’ (Bossuyt
and Dubois [2001:41] identified BMNH 1947.2.6.41 and
BMNH 1947.2.6.42 as syntypes)
Philautus cornutus Van Kampen 1923:274 (new combina-
tion)
Rhacophorus (Philautus) cornutus Ahl 1931:53, 68 (new
combination)
Philautus (Philautus) cornutus Bossuyt and Dubois 2001
(new combination)
Philautus cornutus Hertwig et al. 2012a:38 (by implication)
Syntypes.—BMNH 1947.2.6.41 and BMNH 1947.2.6.42.
Referred specimens (five).—Five adult females as
follows. Jambi: Gunung Kerinci (MZB.Amph.26178,
1.740948S, 101.259148E, elev. 1907 m; UTA-A63817, UTA-
A63818, MZB.Amph.26179, and UTA-A 63819, 1.74578S,
101.258448E, elev. 1838 m).
Diagnosis.—A moderately sized species (females ¼24.0–
25.8 SVL, n¼5) with a sharply angular snout and canthus,
relatively long legs (CrL/SVL ¼0.59–0.66), and four
phalanges free of webbing on the preaxial side of toe IV.
Comparison with Sumatran Philautus.—This species is
most similar to P. refugii and P. thamyridion. It is larger
(females ¼24.0–25.8 SVL, n¼5) than P. refugii (females ¼
18.2–20.5 SVL, n¼4) and P. thamyridion (females ¼17.9–
22.2 SVL, n¼19). The preaxial surface of the thigh lacks a
distinctive pattern. In P. refugii the preaxial surface of the
thigh is boldly patterned, with light spots on a dark field.
There are four phalanges free of webbing on the preaxial
side of toe IV. In P. refugii there are 3.25 or fewer phalanges
free of webbing on toe IV. In P. thamyridion, the webbing of
the feet is slightly less extensive. The canthus is sharply
angular in P. cornutus, angular to rounded in P. thamyridion.
In P. cornutus the loreal region is vertical and strongly
concave; it is vertical to sloped in P. thamyridion.InP.
thamyridion there is usually a pair of enlarged tubercles in
the interorbital region; these are absent in P. cornutus.
Philautus amabilis,P. kerangae,P. larutensis,P. polymor-
FIG. 4.—Oscillograms of individuals notes from the vocalizations in Fig. 3.
Philautus amabilis (A), P. larutensis (B), P. polymorphus (C), P. thamyridion
(D), and P. ventrimaculatus (E). Note that the scale differs between graphs.
The amplitudes at the extremes of the call of P. thamyridion exceeded the
capabilities of the recorder, resulting in the clipped appearance.
77
WOSTL ET AL.—SUMATRAN PHILAUTUS
TABLE 2.—Species used in this study and the GenBank accession numbers of the associated genetic sequences.
Species Catalog number GenBank number Source
Buergeria oxycephala SCUM 050267YJ EU215524 Li et al. 2008
Chiromantis vittatus KIZ 0001Rao GQ285684 Li et al. 2009
Feihyla kajau FMNH 269090 KC465789 Li et al. 2013
Feihyla palpebralis 712 GQ285681 Li et al. 2009
Gracixalus gracilipes AMNH A 163897 DQ283051 Frost et al. 2006
Gracixalus jinxiuensis KIZ 061210YP EU215525 Li et al. 2008
Kurixalus appendiculatus KUHE 52141 AB933307 Nguyen et al. 2014a
Kurixalus idiootocus UMFS 5702 DQ283054 Frost et al. 2006
Liuixalus hainanensis HN 0806039 KC465827 Li et al. 2013
Liuixalus romeri KIZ 061205yP EU215528 Li et al. 2008
Nyctixalus margaritifer KUHE 26135 LC012864 Nguyen et al. 2015
Nyctixalus pictus FMNH 231095 DQ283133 Frost et al. 2006
Philautus abditus AMS-R 171541 KF723226 Stuart et al. 2013
Philautus abditus VNMN 03461 AB933308 Nguyen et al. 2014b
Philautus acutirostris TNHC 59857 AY326059 Darst and Canatella 2004
Philautus acutirostris TNHC 59861 AF458137 Wilkenson et al. 2002
Philautus acutus NMBE 1056430 JX091302 Hertwig et al. 2012b
Philautus amoenus UNIMAS 8052 KC961076 Hertwig et al. 2013
Philautus aurantium UNIMAS 8666 JN705367 Hertwig et al. 2012a
Philautus aurifasciatus UTA-A 64770 KY435417 This study
Philautus aurifasciatus MZB 16395 KJ802924 Nguyen et al. 2014
Philautus bunitus UNIMAS 9045 JN705368 Hertwig et al. 2012a
Philautus cf. larutensis NMBE 1056443 AF026366 Richards and Moore 1998
Philautus amabilis UTA-A 63816 KY435420 This study
Philautus amabilis MZB.Amph.26879 KY435418 This study
Philautus amabilis UTA-A 63814 KY435419 This study
Philautus cornutus MZB.Amph.26178 KY435421 This study
Philautus cornutus MZB.Amph.26187 KY435422 This study
Philautus davidlabangi KUHE 19594 AB847127 Matsui et al. 2014
Philautus disgregus FMNH 231141 KC961077 Hertwig et al. 2013
Philautus everetti KU 309610 JN705377 Hertwig et al. 2012a
Philautus hosii NMBE 1057287 JN705384 Hertwig et al. 2012a
Philautus ingeri NMBE 1056435 JN705385 Hertwig et al. 2012a
Philautus juliandringi NMBE 1056439 JN705378 Hertwig et al. 2012a
Philautus kakipanjang BH 79 KX440525 No associated publication
Philautus kerangae MZB.Amph.26739 KY435423 This study
Philautus kerangae NMBE 1056437 KC961079 Hertwig et al. 2013
Philautus larutensis MZB.Amph.26152 KY435424 This study
Philautus larutensis LSUHC 8872 KY435426 This study
Philautus larutensis MZB.Amph.26866 KY435425 This study
Philautus macroscelis NMBE 1056486 JN705375 Hertwig et al. 2012a
Philautus mjobergi KUHE 53096 KT445972 Dehling et al. 2016
Philautus mjobergi NMBE 1056434 JN705380 Hertwig et al. 2012a
Philautus nephophilus BORNEENSIS 22666 KT445971 Dehling et al. 2016
Philautus petersi Tissue Only KY435427 This study
Philautus polymorphus MZB.Amph.26753 KY435430 This study
Philautus polymorphus MZB.Amph.26789 KY435431 This study
Philautus polymorphus UTA-A 63940 KY435432 This study
Philautus refugii UTA-A 63968 KY435434 This study
Philautus refugii UTA-A 63963 KY435433 This study
Philautus refugii ZMH A10415 JN705383 Hertwig et al. 2012a
Philautus surdus CAS 219932 AF458138 Wilkenson et al. 2002
Philautus tectus NMBE 1056451 JN705370 Hertwig et al. 2012a
Philautus tectus NMBE 1057080 JN705369 Hertwig et al. 2012a
Philautus thamyridion UTA-A 63982 KY435437 This study
Philautus thamyridion MZB.Amph.26763 KY435435 This study
Philautus thamyridion UTA-A 64001 KY435438 This study
Philautus thamyridion MZB.Amph.26806 KY435436 This study
Philautus umbra NMBE 1056454 JN705379 Hertwig et al. 2012a
Philautus ventrimaculatus UTA-A 63868 KY435429 This study
Philautus ventrimaculatus MZB.Amph.26815 KY435428 This study
Philautus vermiculatus LSUHC 8870 KY435439 This study
Philautus vermiculatus LSUHC 8871 KY435440 This study
Philautus worcesteri FMNH 250626 GQ204707 Meegaskumbura et al. 2015
Polypedates braueri LJT 73 KF053220 Pan et al. 2013
Polypedates otilophus KUHE 17264 AB907717 No associated publication
Rhacophorus gauni FMNH 273928 JX219456 Li et al. 2012
Rhacophorus kio KUHE 55170 AB781700 Matsui et al. 2013
Theloderma horridum KUHE 52582 LC012861 Nguyen et al. 2015
Theloderma licin KUHE 19426 LC012859 Nguyen et al. 2015
78 Herpetological Monographs 31, 2017
FIG. 5.—Maximum likelihood (ML) estimate of the phylogeny of Sunda Shelf Philautus. Nodes supported by either Bayesian or ML analyses (posterior
probability [PP] 0.95, ML 75) are annotated with PPs above the branch and bootstrap support values below. A color version of this figure is available
online.
79
WOSTL ET AL.—SUMATRAN PHILAUTUS
TABLE 3.—Uncorrected pairwise distance between Sumatran Philautus and representatives of other Sunda Shelf species.
1 2 3 4 5 6 7 8 9 1011121314151617181920
1P. amabilis MZB.Amph.26879 Aceh, Sumatra
2P. amabilis UTA-A 63814 Sumatera Barat 0.002
3P. aurifasciatus UTA-A 64770 Jawa Barat 0.135 0.130
4P. bunitus UNIMAS 9045 Sabah, Borneo 0.106 0.101 0.166
5P. cornutus MZB.Amph.26187 Jambi,
Sumatra
0.056 0.056 0.132 0.111
6P. kerangae MZB.Amph.26739 Lampung,
Sumatra
0.102 0.096 0.174 0.015 0.113
7P. kerangae NMBE 1056437 Sarawak, Borneo 0.110 0.104 0.166 0.027 0.106 0.039
8P. larutensis MZB.Amph.26152 Lampung,
Sumatra
0.099 0.097 0.151 0.138 0.115 0.147 0.144
9P. larutensis LSUHC 8872 Perak Malaysia 0.110 0.106 0.155 0.135 0.130 0.141 0.144 0.007
10 P. larutensis MZB.Amph.26866 Aceh,
Sumatra
0.101 0.100 0.115 0.098 0.117 0.104 0.103 0.002 0.000
11 P. cf. larutensis NMBE 1056443 Sarawak,
Borneo
0.116 0.110 0.155 0.135 0.129 0.140 0.144 0.061 0.062 0.048
12 P. petersi Great Natuna Island 0.138 0.139 0.165 0.143 0.156 0.141 0.152 0.153 0.168 0.155 0.173
13 P. polymorphus MZB.Amph.26753 Jambi,
Sumatra
0.032 0.034 0.167 0.146 0.065 0.151 0.151 0.143 0.152 0.114 0.144 0.146
14 P. polymorphus MZB.Amph.26789 Sumatera
Selatan
0.034 0.032 0.128 0.112 0.065 0.109 0.110 0.119 0.135 0.121 0.128 0.147 0.006
15 P. refugii UTA-A 63968 Sumatera Utara 0.128 0.120 0.149 0.149 0.147 0.157 0.146 0.119 0.124 0.093 0.122 0.174 0.152 0.123
16 P. refugii UTA-A 63963 Bengkulu, Sumatra 0.128 0.120 0.125 0.106 0.147 0.112 0.117 0.093 0.097 0.093 0.105 0.174 0.119 0.123 0.000
17 P. refugii ZMH-A10415 Sarawak, Borneo 0.131 0.123 0.161 0.158 0.150 0.164 0.157 0.125 0.130 0.099 0.130 0.176 0.158 0.127 0.019 0.006
18 P. thamyridion MZB.Amph.26763 Lampung,
Sumatra
0.061 0.060 0.176 0.154 0.047 0.161 0.160 0.160 0.170 0.137 0.154 0.161 0.089 0.071 0.175 0.145 0.175
19 P. thamyridion UTA-A 64001 Sumatera
Selatan
0.050 0.049 0.133 0.129 0.050 0.132 0.132 0.126 0.138 0.132 0.131 0.157 0.065 0.065 0.137 0.138 0.139 0.012
20 P. ventrimaculatus UTA-A 63868 Jambi,
Sumatra
0.067 0.068 0.188 0.151 0.073 0.155 0.156 0.144 0.149 0.120 0.151 0.153 0.088 0.079 0.170 0.134 0.177 0.101 0.083
21 P. ventrimaculatus MZB.Amph.26815 0.067 0.068 0.150 0.122 0.075 0.122 0.118 0.122 0.131 0.122 0.134 0.159 0.085 0.077 0.132 0.132 0.139 0.090 0.085 0.011
80 Herpetological Monographs 31, 2017
FIG. 6.—Philautus cornutus (A and B, UTA-A 63817, female, 24.52 mm snout–vent length [SVL], Gunung Kerinci, Jambi). Philautus refugii (C and D,
UTA-A 63966, female, 19.99 mm SVL, Gunung Sorik Merapi Sumatera Utara). P. petersi (E and F, Gunung Ranai, Great Natuna Island, specimens not
collected). A color version of this figure is available online.
81
WOSTL ET AL.—SUMATRAN PHILAUTUS
phus,andP. ventrimaculatus all have 3.75 or fewer
phalanges of toe IV free of webbing.
Comparison with other Sunda Shelf Philautus.—This
species lacks vomerine teeth. Vomerine teeth are present in
P. bunitus,P. macroscelis,P. hosii, and P. ingeri. There are
four phalanges free of webbing on the preaxial side of toe IV.
There are 3.5 or fewer phalanges on the preaxial side of toe
IV free of webbing in P. acutus,P. amoenus,P. aurantium, P.
aurifasciatus,P. bunitus,P. davidlabangi,P. disgregus,P.
erythrophthalmus,P. gunungensis,P. hosii,P. ingeri,P.
jacobsoni,P. juliandringi,P. kakipanjang,P. kerangae,P.
macroscelis,P. mjobergi,P. nephophilus,P. petersi,P.
refugii,P. saueri,P. tectus, and P. vermiculatus. This species
lacks a lingual papilla, which is present in P. umbra. There
are distinct conical tubercles on the eyelids and there is a
fleshy rostral protrusion in females. Philautus umbra does
not have tubercles on the eyelid and females do not have a
rostral protrusion.
Variation.—On the basis of five adult females from Jambi
Province, Sumatra. SVL 23.99–25.78 (24.74 60.66); HL
9.33–10.8 (9.90 60.56); HL/SVL 0.39–0.42 (0.40 60.01);
HW 9.17–10.80 (9.90 69.41); HW/HL 0.88–0.99 (0.95 6
0.05); IND 2.75–3.05 (2.93 60.17); IND/HL 0.26–0.31
(0.30 60.02); EN 1.93–2.30 (2.14 60.15); EN/HL 0.21–
0.23 (0.22 60.01); SnL 3.82–4.37 (4.20 60.24); SnL/HL
0.40–0.44 (0.42 60.02); IOD 2.94–3.30 (3.09 60.16); IOD/
EN 1.35–1.52 (1.45 60.08); IOD/IND 1.10–1.10 (1.06 6
0.03); FaL 5.80–6.30 (6.10 60.26); FaL/SVL 0.24–0.26
(0.25 60.01); HnL 6.95–7.60 (7.20 60.26); HnL/SVL 0.27–
0.31 (0.29 60.02); HnL/FaL 1.14–1.21 (1.18 60.04); ThL
13.20–14.07 (13.65 60.31); ThL/SVL 0.53–0.57 (0.55 6
0.01); CrL 14.54–16.17 (15.44 60.63); CrL/SVL 0.59–0.66
(0.63 60.03); CrL/ThL 1.10–1.18 (1.13 60.03); TarL 8.85–
9.20 (8.83 60.32); TarL/SVL 0.34–0.37 (0.36 60.01); FL
10.55–12.50 (11.56 60.80); FL/SVL 0.43–0.51 (0.47 6
0.04); FL/TarL 1.26–1.39 (1.31 60.05).
The snout is pointed in dorsal view and acute in profile.
The canthus rostralis is sharply angular and straight to slightly
concave. There is a distinct constriction immediately posterior
to the naris. The loreal region is vertical and concave. The
nostril is small, ovoid, oriented laterally and slightly posteri-
orly. The pupil is horizontal. The tympanum is indistinct to
barely discernable; when visible the annulus is present. The
supratympanic fold is straight to slightly curved and extends
from the eye to just above the insertion of the forelimb. The
palpebral membrane is mostly clear centrally with a thin band
of pigmentation the color of the eyelid along the rim, fine
speckling peripherally, and some patterning on the posterior
portion that is continuous with that of the adjacent skin. The
pupil is horizontal. There is no lingual papilla and no
vomerine teeth. The choanae are small and round to ovoid,
separated by 5–7.5 times their greatest diameter. The tongue
is bifurcate posteriorly and about half free.
On the hands, the palmar tubercle is oblong and partially
to fully divided lengthwise; the thenar tubercle is ovoid. The
subarticular tubercles are small and round and there is a
small supernumerary tubercle present on the first phalanx of
finger III or fingers III and IV. The pads of the finger are
entire and slightly broadened to round. A fine dermal fringe
is present on fingers II–IV, extending to the disk. There is
very slight fleshy webbing between fingers III and IV. The
relative finger length is I ,II ,IV ,III.
The plantar surface has numerous small tubercles and one
enlarged tubercle at the base of metatarsal IV. The inner
metatarsal tubercle is small and oblong. Subarticular tubercles
of the toes are small and round. The proximal subarticular
tubercle of toe IV is absent and the proximal subarticular
tubercle of toe V is tiny. Supernumerary tubercles are present
in any combination on the first phalanx of toes III–V. The toe
pads are entire and round with a distinct ungual flap. There is a
dermal fringe on toes II–V that extends to the disk. Relative toe
length is I ,II ,III V,IV. The webbing of the feet is
reduced. Webbing formula is I(2)–(2.75–3)II(2–2
þ
)–(3.5–
3.75)III(2.5–2.75)–(4)IV(3.25–3.75)–(2–2.75)V.
A fleshy projection is on the rostrum of the individuals we
examined. However, this character tends to be sexually
dimorphic in Philautus and we have not examined males. On
the eyelids, there are several distinct conical tubercles and
there is a row of conical tubercles along the ventral margin of
the mandible. The dorsum is smooth with scattered round
tubercles. The postorbital and suprascapular regions have a row
of well-spaced enlarged conical tubercles that converge
posteriorly to form a ‘‘V’’. The antecubital, thigh, and crus
are tuberculate dorsally. The tarsus has a row of tubercles along
the postaxial margin that extends to the first phalanx of toe V.
There is no calcar, but the heel can have some very small
rounded tubercles. There is a small patch of skin inferior to the
vent with enlarged granules that extends to the ventral surface
and laterally onto the posterior surface of the thigh. The ventral
surface itself is granular, areolate on the throat. The m.
cutaneous pectoris is present and the pectoral septum is a
broad sheet inserted across the breadth of the pectoral region.
In life, the dorsum is uniformly dark purple brown–light
brown. Most individuals we observed were patternless
dorsally, but one (UTA-A 63819) had a dark forward-
pointing V originating at the sacral humps. The tubercles are
lighter in color than the dorsum. There are usually thin dark
bands on the antecubital, thigh, and crus. In most specimens,
there is an indistinct light interorbital bar. The supra-
tympanic fold is distinctly lighter and bordered inferiorly by
a dark postorbital stripe. All specimens have a distinctive
black spot that surrounds the vent. The ventral surface is
light brown with darker markings on the throat and chest.
The undersides of the legs are marked with fuzzy-edged light
flecks. The iris is strongly bicolored, golden orange
superiorly and inferiorly with dark brown wedges that
extend from the anterior and posterior margins of the pupil
to the margin of the eye.
Distribution and habitat.—We have only encountered
this species at elevations between 1529 and 1907 m above
sea level (asl). on Gunung Kerinci and near Danau Tujuh,
both in Jambi Province. In all instances, we encountered this
species in mature forest.
Philautus kerangae Dring 1987
Figs. 7, 14–16, 19
Philautus kerangae Dring 1987:28.
Philautus (Philautus) kerangae Bossuyt and Dubois 2001:57
(new combination)
Philautus kerangae Hertwig et al. 2012a:38 (by implication)
Holotype.—BMNH 1978.1771. An adult male collected
at Kerangas Camp, Gunung Mulu National Park, Fourth
Division, Sarawak, Malaysia.
82 Herpetological Monographs 31, 2017
Referred specimens (one).—Lampung: approximately 1
km north of Kubu Perahu, subadult female (MZB.Amph.
26739, 05.064168S, 104.034638E, 790 m).
Diagnosis.—A moderate-sized species (SVL ¼25.8) with
vomerine teeth and extensive pedal webbing (2.5 or fewer
phalanges of toe IV free of webbing). The inguinal region,
preaxial and postaxial surfaces of the thigh and crus, and
preaxial dorsal surface of the foot are distinctly patterned
with bold dark marks on enamel white.
Comparison with Sumatran Philautus.—This species
has vomerine teeth; they are absent in all other Philautus on
Sumatra (P. amabilis,P. cornutus,P. larutensis,P. thamyr-
idion,P. polymorphus,P. refugii, and P. ventrimaculatus).
Comparison to other Sunda Shelf Philautus.Phi-
lautus kerangae has vomerine teeth; they are absent in P.
acutus,P. amoenus,P.aurantium,P. aurifasciatus,P.
davidlabangi,P. disgregus,P. erythrophthalmus,P. jacobso-
ni,P. juliandringi,P. kakipanjang,P. mjobergi,P.neph-
ophilus,P. petersi,P. saueri,P. umbra,andP. vermiculatus.
The m. cutaneous pectoris is absent in this species, but
present in P. hosii and P. ingeri. There are approximately two
phalanges of toe IV free of webbing; P. tectus has
approximately three phalanges of toe IV free of webbing.
The pattern on the flank, preaxial and postaxial surfaces of
the thigh and crus, and axillary region that consists of dark
brown bars on an enamel white field distinguishes this
species from P. bunitus, in which the flank, sides, and belly
are largely unmarked and yellow–orange, and P. macroscelis,
in which the preaxial surface of the thigh, inguinal region,
and lower sides are bright yellow occasionally with brown
spots.
Description of Sumatran specimen.—SVL 25.79; HL
10.64; HL/SVL 0.41; HW 10.39; HW/HL 0.98; IND 2.93;
IND/HL 0.27; EN 2.15; EN/HL 0.20; SnL 3.88; SnL/HL
0.36; IOD 2.85; IOD/EN 1.33; IOD/IND 0.97; FaL 6.70;
FaL/SVL 0.26; HnL 7.65; HnL/SVL 0.30; HnL/FaL 1.14;
ThL 13.22; ThL/SVL 0.51; CrL 14.16; CrL/SVL 0.55; CrL/
ThL 1.07; TarL 7.40; TarL/SVL 0.29; FL 11.16; FL/SVL
0.43; FL/TarL 1.51.
Snout subelliptical and slightly mucronate in dorsal view,
rounded, almost vertical in profile; canthus rostralis weakly
angular and concave; loreal region vertical and slightly
FIG. 7.—Philautus kerangae, MZB.Amph.26739, female, 25.79 mm, Kubu Perahu, Lampung. Pictures C and D taken a couple of hours after pictures A
and B; note the change in the extent and prominence of the dorsal tubercles. A color version of this figure is available online.
83
WOSTL ET AL.—SUMATRAN PHILAUTUS
concave; nostril small, round, and laterally oriented;
tympanum distinct, covered in skin the same color and
texture as the surrounding area, annulus present, superior
margin covered by supratympanic fold; supratympanic fold
extends from posterior margin of eye to the insertion of
forelimb; pupil horizontal; palpebral membrane with a thin
band of pigmentation along rim, superior half mostly clear,
inferior half with dense brown mottling; lingual papilla
absent; vomerine teeth present; choanae round, straight-line
distance between choanae about 3.5 times greater than
greatest diameter; tongue broad, bifurcate posteriorly,
approximately half free, each bifurcation about one-quarter
of tongue length.
Palmar tubercle round, divided lengthwise; thenar
tubercle round and indistinct; subarticular tubercles round;
proximal subarticular tubercle of fingers III and IV small;
supernumerary tubercles absent; finger pads entire, broad-
ened; ungual flap present on all fingers; dermal fringe on all
fingers to disc; webbing present between all fingers, fleshy;
only half of proximal phalanx of fingers I and IV free of
webbing; relative finger length I ,II ,IV ,III.
Plantar surface with numerous small tubercles; outer
metarsal tubercle absent; inner metatarsal tubercle oblong;
subarticular tubercles round; proximal subarticular tubercle
of toe IV tiny; supernumerary tubercles on first phalanx of
toes IV and V; toe pads entire, slightly broadened, smaller
than finger pads; ungual flap present on all toes; relative toe
length I ,II ,III ¼V,IV; dermal fringe to disc on all
toes; webbing formula I1.5–2 II1.5–2.25III1.25–2.5IV2–
1.25V.
Dorsal surface of snout anterior to eyes and lips with
several small tubercles; rostrum with very small tubercle at
the tip; eyelid with small distinct conical tubercles; dorsum
of trunk with scattered tubercles; enlarged tubercles in the
postorbital, supratympanic, and suprascapular regions;
dorsal surface of antecubital, trunk, thigh, and crus with
distinct tubercles; postaxial margin of tarsus and foot with
row of tubercles; calcar absent; heel with small round
tubercles; patch of skin with enlarged granules below vent
extending to ventral surface and laterally for about half of the
thigh; ventral skin granular, weakly areolate on throat; m.
cutaneous pectoris absent; pectoral septum attached broadly
across pectoral region.
Dorsally the specimen is green with brown mottling.
There are brown bars on the lips and regular brown bands
on the dorsal surface of the thigh, crus, tarsus, and foot. The
snout is brown and there are three thin brown bands in the
interorbital region, the middle of which extends to the
margin of the eyelids. The axilla, inguinal region, preaxial
and postaxial surfaces of the thigh, inferior postaxial portion
of the crus, and preaxial/superior surface of the foot is bright
enamel white with large dark-brown clean-edged blotches.
Ventrally, the specimen is white with dusky mottling on the
throat and pectoral region. The central abdomen is brownish
with light flecks. The iris is light gold with bold black
vermiculate pattern.
Comments.—This species can undergo a dramatic shift
in the appearance and prominence of tubercles on the body.
We photographed this specimen in life twice, a couple of
hours apart. In the first set of pictures, it appears strongly
tuberculate with conical tubercles scattered across the
dorsum and pronounced tubercles in the interorbital,
postoccipital, supratympanic, and suprascapular regions. In
the second set of photographs, the dorsum is essentially
smooth. In preservative, the specimen is mostly smooth. Our
assignment of this specimen to P. kerangae is tentative. See
the Discussion for more details.
Philautus larutensis (Boulenger 1900b)
Figs. 8, 9, 17–19
Ixalus petersi Boulenger 1900a:185. ‘‘Specimens from Mt.
Penrissen, Dulit, and Kina Balu in Borneo; also from
Great Natuna’’ (type series identified as BMNH
1899.12.8.10, BMNH 1909.8.18.5, BMNH 1892.6.3.16,
BMNH 1895.5.1.41, BMNH 1895.5.1.42, BMNH
1947.2.27.19 by Dring [1987:41]).
Ixalus larutensis Boulenger 1900b:187. ‘‘ Several specimens
from Larut Hills’’ (BMNH 1900.6.14.29–31 identified as
syntypes [Dring 1987:47]; added to synonymy of P.
petersi by Smith [1930:116], Bourret [1942:456] and
Dring [1987:41]).
Ixalus castanomerus Boulenger 1905:39. ‘‘ A single specimen
from Bukit Kutu, Selangor’’ (Holotype identified as
BMNH 1905.1.28.8 [Dring 1987:47]; added to synony-
my of P. petersi by Smith [1925:10], Smith [1930:116],
Bourret [1942:456], and Dring [1987:41]).
Philautus larutensis Stejneger 1905:346 (by implication after
finding Ixalus preoccupied).
Philautus similis Van Kampen 1923 syn. nov. (by present
designation).
Philautus petersi Smith 1930:116 (new arrangement in part.
P. castanomerus and P. larutensis considered synonyms
of P. petersi).
Rhacophorus (Philautus)petersi Ahl 1931:54, 86 (new
combination).
Rhacophorus (Philautus)larutensis Ahl 1931:54, 86 (new
combination).
Rhacophorus (Philautus)castanomerus Ahl 1931:54, 86 (new
combination).
Philautus petersi Bourret 1942:456 (P. castanomerus and P.
larutensis considered synonyms of P. petersi).
Philautus (Philautus)petersi Bossuyt and Dubois 2001:36 (in
part, new combination).
Philautus petersi Hertwig et al. 2012a:38 (by implication).
Lectotype.—BMNH 1947.2.6.36. An adult female from
the Larut Hills, Perak State, Malaysia (designated by Bossuyt
and Dubois 2001).
Referred specimens (37).—We examined 26 adult
males and 11 adult females collected from across Sumatra
as follows. Aceh: vicinity of Ise-Ise, one male (UTA-A 63823,
4.226468N, 97.189078E, elev. 1826 m); vicinity of Takengon,
three males (UTA-A 63820, 4.506698N, 96.860798E, elev.
1637 m; MZB.Amph.26866, and UTA-A 63821, 4.505938N,
96.861358E, elev. 1643 m). Jambi: Gunung Kunyit, one
female (UTA-A 63830, 2.260138S, 101.495128E, elev. 1428
m); vicinity of Danau Tujuh, three females (UTA-A 63826,
UTA-A 63827, and UTA-A 63828, 1.709748S, 101.370898E,
elev. 1549 m) and one male (UTA-A 63829, 1.711668S,
101.369328E, elev. 1512 m). Lampung: vicinity of Ngarip,
three females (UTA-A 63831, UTA-A 63833, and UTA-A
63837, 5.282128S, 104.557738E, elev. 1358 m) and two males
(UTA-A 63832, 5.282188S, 104.557738E, elev. 1358 m; UTA-
A 63834, 5.280698S, 104.556898E, elev. 1404 m); vicinity of
84 Herpetological Monographs 31, 2017
FIG. 8.—Philautus larutensis from Sumatra. UTA-A 63865, male, snout–vent length (SVL) 21.8 mm Gunung Sibayak, Sumatera Utara (A).
MZB.Amph.26766, female, 24.27 mm SVL, Ranau Danau, Lampung (B). UTA-A 63823, male, 23.3 mm SVL vicinity of Ise-Ise, Aceh (C and D). Note the
characteristic light rectangles on the dorsal surface of the thigh. UTA-A 63840, female, SVL 32.02 mm, Gunung Singgalang Sumatera Barat (E).
MZB.Amph.26152, male, 24.92 mm, Gunung Tanggamus, Lampung (F). A color version of this figure is available online.
85
WOSTL ET AL.—SUMATRAN PHILAUTUS
FIG. 9.—Holotype of Philautus similis RMNH 5066, female, 28.9 mm snout–vent length (SVL), Gunung Talakmau, Sumatera Barat showing rostral
tubercle (A), light rectangular ovals on dorsal surface of thigh (C), and the extent of pedal webbing (E). The same characters (B, D, and F respectively)ina
contemporary specimen of P. larutensis (UTA-A 63827, female, SVL 27.38 mm, from Danau Tujuh, Jambi Province). A color version of this figure is available
online.
86 Herpetological Monographs 31, 2017
Ranau Danau, one male (UTA-A 63836, 4.941698S,
103.853578E, elev. 1337 m). Sumatera Barat: Gunung
Singgalang, one female (UTA-A 63840, 0.375238S,
100.363188E, elev. 1485 m) and six males (UTA-A 63839,
MZB.Amph.26867, MZB.Amph.26868, UTA-A 63841,
MZB.Amph.26870, and MZB.Amph.26871, 0.375238S,
100.363188E, elev. 1485 m). Sumatera Utara: Air Terjur
Sikulipan, one male (UTA-A 63843, 3.244128N, 98.53598E,
elev. 1257 m); Batang Gadis, two males (UTA-A 63858 and
UTA-A 63859, 0.707848N, 99.520098E, elev. 1309 m);
Gunung Pangulubao, three males (UTA-A 63852,
2.609628N, 99.048668E, elev. 1473 m; UTA-A 63853,
2.604868N, 99.046288E, elev. 1425 m; UTA-A 63854,
2.603338N, 99.045128E, elev. 1410 m). Gunung Sibayak,
one female (MZB.Amph.26780, 3.214628N, 98.497938E,
elev. 1570 m) and three males (UTA-A 63847, UTA-A
63849, and UTA-A 63851, 3.214628N, 98.497938E, elev.
1570 m); Gunung Sibuatan, two females (MZB.Amph.26740
and UTA-A 63863, 2.910768N, 98.463138E, elev. 1608 m);
Gunung Sorik Merapi, one male (UTA-A 63844, 0.701648N,
99.552628E, elev. 1407 m), Gunung Tampulon Anjing, one
male (UTA-A 63865, 1.684498N, 99.347378E, elev. 1243 m);
Kota Baringen Julu, one male (UTA-A 63867, 0.665998N,
99.572178E, elev. 1320 m).
Diagnosis.—A moderate to large species (males ¼20.2–
25.4 SVL, n¼26; females ¼23.8–32.0, n¼11) that is highly
variable in coloration and proportions. There are three or
fewer phalanges free of webbing on the postaxial margin of
toe IV. Males have a well-developed nuptial pad on the first
phalanx of the first finger and females have an enlarged
fleshy tubercle on the rostrum. There is a row of tubercles on
the ventral margin of the mandible. Most individuals have
distinctive light ovals/bars on the dorsal surface of the thigh.
Comparison with Sumatran Philautus.—This species is
superficially similar to both P. amabilis and P. polymorphus.
It is readily discerned from each by the presence of a nuptial
pad in males and an enlarged fleshy tubercle on the snout of
females. The tubercles on the eyelid are smaller and less
distinct than those in P. polymorphus. This species lacks
vomerine teeth; they are present in P. kerangae. The distinct
row of tubercles on the ventral margin of the mandible
distinguishes this species from P. amabilis (if present the
tubercles are only weakly developed in P. amabilis). There
are three or fewer phalanges of toe IV free of webbing.
Philautus cornutus,P. thamyridion, and P. ventrimaculatus
all have 3.5 or more phalanges of toe IV free of webbing. A
nuptial pad is present in male P. larutensis; it is absent in
male P. amabilis,P. ventrimaculatus,P. polymorphus, and P.
thamyridion. There is a fleshy protrusion on the snout of
adult females. This feature is absent in female P. amabilis,P.
ventrimaculatus,P. polymorphus,andP. thamyridion. This
species is larger (males ¼20.2–25.4 SVL, n¼26) than P.
refugii (males ¼16.5–16.9 SVL, n¼4). The preaxial surface
of the thigh is largely unpatterned. The preaxial surface of
the thigh in P. refugii has bold light spots on a dark field.
Comparison with other Sunda Shelf Philautus.—This
species is smaller (males ¼20.2–25.4 SVL, n¼2) than its
former synonym (P. petersi males ¼29.1–34.4 SVL, n¼5).
There is a row of conical tubercles along the ventral margin
of the mandible, which is absent in P. petersi. Males have a
nuptial pad. Male P. petersi lack a nuptial pad. Females have
an upturned fleshy protrusion on the snout. There is no such
structure in female P. petersi. Vomerine teeth are absent.
They are present in P. bunitus,P. hosii,P. ingeri, and P.
macroscelis. The m. cutaneous pectoris is present in this
species and absent from P. aurantium (and presumably P.
gunungensis), P. disgregus,P. erythrophthalmus, and P.
tectus. The pedal webbing, with three or fewer phalanges of
toe IV free of webbing, is more extensive than P. umbra, with
3.5 phalanges or more free of webbing on toe IV. The pedal
webbing is less extensive than in P. amoenus,P. davidla-
bangi,P. jacobsoni, and P. saueri, all of which have 2.5
phalanges or fewer phalanges free of webbing on the preaxial
side of toe IV. Male P. acutus,P. aurantium,P. bunitus,P.
disgregus,P. gunungensis,P. kerangae, and P. vermiculatus
lack a nuptial pad. Female P. juliandringi and P. mjobergi
lack a fleshy protrusion on the snout. This species is larger
(males ¼20.2–25.4 SVL, n¼26) than P. juliandringi (males
¼18.9–20.1 SVL [Dehling 2010]) and P. nephophilus (males
¼17.0–18.6, n¼6; Dehling et al. 2016). A small but distinct
calcar is present in this species but absent in P. aurifasciatus.
Without more data, we are unable to distinguish this
species from P. kakipanjang. We note, however, that two
characters usually present in the specimens we examined
from Sumatra, a lingual papilla and a small but distinctive
calcar, are absent in P. kakipanjang (Dehling and Dehling
2013). Relatively longer legs distinguish P. kakipanjang from
Bornean populations of P. larutensis (Dehling and Dehling
2013). However, the Sumatran specimens of P. larutensis
and P. kakipanjang overlap in this character. The two species
are genetically distinct.
Variation.—On the basis of 26 adult males and 11 adult
females from Sumatra. SVL 20.20–25.39 (22.59 61.23),
23.18–32.02 (29.04 62.46); HL 8.45–10.13 (9.33 60.52),
9.17–12.72 (11.83 61.00); HL/SVL 0.40–0.43 (0.41 60.01),
0.39–0.43 (0.41 60.010; HW 8.62–10.31 (9.46 60.49);
HW/HL 0.97–1.09 (1.01 60.01), 0.95–1.06 (1.00 60.02);
IND 1.95–2.55 (2.27 60.14), 2.35–3.10 (2.85 60.25); IND/
HL 0.21–0.27 (0.24 60.01), 0.21–0.26 (0.24 60.01); EN
1.81–2.28 (2.02 60.13), 2.16–2.78 (2.53 60.19); EN/HL
0.20–0.24 (0.22 60.01), 0.20–0.24 (0.22 60.01); SnL 3.26–
4.17 (3.66 60.24), 3.85–5.3 (4.81 60.46); SnL/HL 0.37–
0.42 (0.39 60.01), 0.38–0.43 (0.41 60.02); IOD 2.35–2.86
(2.58 60.13), 2.70–4.0 (3.12 60.35); IOD/EN 1.16–1.40
(1.28 60.06), 1.14–1.48 (1.23 60.09); IOD/IND 1.02–1.30
(1.14 60.07), 0.95–1.33 (1.10 60.11); FaL 4.80–6.00 (5.45
60.30), 5.50–7.75 (7.02 60.63); FaL/SVL 0.20–0.27 (0.24
60.01), 0.22–0.26 (0.24 60.01); HnL 5.95–7.80 (6.82 6
0.40), 7.25–9.30 (8.75 60.57); HnL/SVL 027–0.32 (0.30 6
0.01), 0.26–0.33 (0.30 60.02); HnL/FaL 1.15–1.50 (1.25 6
0.08), 1.07–1.33 (1.25 60.08); ThL 10.51–13.16 (11.91 6
0.69), 11.72–16.00 (14.72 61.15); ThL/SVL 0.50–0.57 (0.53
60.20), 0.48–0.54 (0.51 60.02); CrL 11.77–14.10 (12.83 6
0.62), 13.52–16.92 (15.95 60.96); CrL/SVL 0.53–0.61 (0.57
60.02), 0.49–0.58 (0.55 60.03); CrL/ThL 1.02–1.17 (1.08
60.04), 1.02–1.15 (1.09 60.05); TarL 6.25–7.75 (7.03 6
0.37), 7.20–8.80 (8.46 60.45); TarL/SVL 0.28–0.34 (0.31 6
0.02), 0.27–0.32 (0.29 60.02); FL 9.15–11.40 (10.40 6
0.65), 11.05–13.91 (13.08 60.79); FL/SVL 0.41–0.51 (0.46
60.02), 0.43–0.48 (0.45 60.020; FL/TarL 1.32–1.59 (1.48
60.08), 1.43–1.63 (1.54 60.06).
In males, the snout is subelliptical when viewed from
above and rounded to vertical in profile. In females, the
snout is subelliptical to pointed in dorsal view and protruding
87
WOSTL ET AL.—SUMATRAN PHILAUTUS
to acute in profile. The difference between the males and
females is caused by the presence of an upturned fleshy
protrusion on the snout of females. The canthus is rounded
and curves medially (is concave); the lores are sloped. The
nostril is small and round to slightly ovoid and oriented
laterally to slightly dorsolaterally. The tympanum is indistinct
and the supratympanic fold curves from the posterior of the
eye to just above the insertion of the forelimb. The pupil is
horizontal. The palpebral membrane is mostly clear with a
thin rim of pigmentation along the rim the color of the eyelid
and small dark flecks inferiorly. A lingual papilla was present
in 26 of the 37 specimens examined. This structure was
absent in seven specimens (MZB.Amph.26866,
MZB.Amph.26871, UTA-A 63834, UTA-A 63836, UTA-A
63839, UTA-A 63853, UTA-A 63865) and unscoreable in an
additional four (MZB.Amph.26865, UTA-A 63821, UTA-A
63822, UTA-A 63841). Vomerine teeth are absent. The
choanae are round to ovoid and squarish, separated by three
to seven times their greatest diameter. The tongue is
bifurcated posteriorly and between two-thirds and one-half
free. Each bifurcation makes up 21–32% of the length of the
tongue.
Males have a prominent nonkeratinized ovoid nuptial pad
on the preaxial side of the proximal phalanx of the first
finger. The palmar tubercle is divided anteriorly. The extent
of the division is variable and the tubercle can be single and
U shaped or divided completely, forming two small
longitudinally oriented tubercles. The thenar tubercle is
elongate to ovoid. There is a row of small tubercles along the
outer margin of the hand, sometimes indistinct. The palmar
surface is pustulose to wrinkled, making it difficult to discern
the tubercles.
Pads on the finger are broadened, especially on fingers III
and IV. There is a slight dermal fringe on fingers I–IV. The
webbing between the digits of the hand is rudimentary,
generally a basal fleshy fringe. It is slightly more extensive in
some specimens where only one-half to three-quarters of the
proximal phalanx of finger IV is free of webbing. Relative
finger length is I ,II ,IV ,III.
On the feet, plantar tubercles are numerous; none is
prominent. There is no outer metatarsal tubercle, and the
inner metatarsal tubercle is oblong and flat. The subarticular
tubercles are round. The proximal subarticular tubercle of
the fourth toe is not discernable, though there is a slight
swelling where it should be. The proximal tubercles of the
third and fifth toes are considerably smaller than the distal
tubercles. No supernumerary tubercles are evident. Relative
toe length is usually I ,II ,III ¼V,IV, though toe V is
occasionally slightly longer than toe III. There is a slight
dermal fringe on toes I–V, occasionally indistinct on toe I.
The webbing formula is I(1.75–2)–(2–2.5)II(1.25–1.5)–
(2.75–3.25)III(1.5–1.75)–(3)IV(2.75–3)–(1.5–2)V.
The dorsal surface of the snout and lips are usually
smooth, tuberculate in only a few specimens. Females have a
distinct protrusion on the snout. There are often tubercles
on the eyelids but they are usually small and sparse. There is
a row of small distinct conical tubercles along the length of
the ventral margin of the mandible. Dorsally, the skin is
mostly smooth. There are two to three enlarged tubercles in
the postocular and suprascapular region arranged in loose
lines that converge posteriorly. The sides between these lines
and the supratympanic fold often bear an additional
prominent tubercle. There is commonly a medial pair of
enlarged tubercles in line with the posterior margin of the
orbit. The forearm, crus, and tarsus bear tubercles, though
they may be indistinct. The thigh is smooth or has a few
small far-spaced tubercles. There is a small but distinct
calcar. The ventral skin is granular to areolate. Specimens
appear considerably more tuberculate in life. The m.
cutaneous pectoris is present and the pectoral septum is
attached across the breadth of the pectoral region.
Coloration and pattern are extremely variable. Specimens
are generally light to dark brown or gray and can be
patterned or not. Occasional individuals display a thin light
dorsal stripe. The ventral coloration is as variable as the
dorsal coloration. It is generally light with dusky flecks, but
can be predominantly dusky with light flecks. Almost all
specimens examined possess a series of light-colored
rectangular–oval bands on the dorsal surface of the thigh
and a light flank overlain by a coarse dark reticulation. The
iris is light gold to brown, usually without a vermiculate
pattern or distinctly darker wedges anterior and posterior to
the pupil.
Vocalization.—The call is a short chattering trill given
intermittently. Each trill lasts 0.5–0.7 s and consists of 12–15
pulsed notes. The relative amplitude of each note either
stays the same throughout the call or increases as the call
progresses. Each note is composed of five to six pulses and
lasts for about 0.02–0.028 s. The internote period is
approximately 0.017–0.024 s and is relatively constant
throughout the call. The dominant frequency of the call is
2325.59–2842.38 Hz and the fundamental frequency is
1162.79–1421.19 Hz. There are harmonics at 4, 6, 8, and
10 times the fundamental frequency. Unedited recordings of
the call are available to listen to or download at the Cornell
Lab of Ornithology Macaulay Library (available at http://
macaulaylibrary.org/) under catalog numbers 219802 and
219803.
Distribution and habitat.—As currently recognized, this
species occurs on Sumatra, Borneo, and the Malaysian
Peninsula. We have encountered this species throughout
Sumatra in mature forests between 1169 and 1826 m asl.
Comments.—The holotype of P. similis shares several
distinct characters with P. larutensis, including the extent of
pedal webbing, an upturned tubercle on the rostrum, a row
of conical tubercles on the mandible, and a distinctive
pattern on the dorsal surface of the thighs that consists of
evenly spaced light rectangular ovals. Additionally, P.
larutensis is widespread throughout Sumatra at the elevation
at which the holotype of P. similis was collected. On the basis
of these observations, and the results of our morphometric
analysis, we consider P. similis Van Kampen 1923 to be a
junior synonym of P. larutensis (Boulenger 1900b). Table 4
provides a comparison of the morphometric data from the
holotype of P. similis and a series of P. larutensis from
Sumatra. Figure 9 provides a photographic comparison of
meristic characters shared between the holotype of P. similis
and a specimen of P. larutensis from Sumatra.
Philautus petersi (Boulenger 1900a)
Figs. 7, 14–16, 19
Ixalus petersi Boulenger 1900a:185. ‘‘Specimens from Mt.
Penrissen, Dulit, and Kina Balu in Borneo; also from
88 Herpetological Monographs 31, 2017
Great Natuna’’ (type series identified as BMNH
1899.12.8.10, BMNH 1909.8.18.5, BMNH 1892.6.3.16,
BMNH 1895.5.1.41, BMNH 1895.5.1.42, BMNH
1947.2.27.19 by Dring [1987:41]).
Philautus petersi Stejneger 1905:346 (by implication after
finding Ixalus preoccupied).
Philautus peterai Barbour 1912:171 (in part; misspelling).
Rhacophorus (Philautus)petersi Ahl 1931:54, 85 (new
arrangement).
Philautus petersi Bourret 1942:455.
Philautus (Philautus)petersi Bossuyt and Dubois 2001 (new
combination, designated a lectotype thereby restricting
the type locality to Great Natuna Island).
Philautus petersi Hertwig et al. 2012a:38 (by implication).
Lectotype.—BMNH 1947.2.27.17 (¼BMNH 1895.5.1.41)
from Great Natuna Island (Bossuyt and Dubois 2001). Sex
unknown, though probably a female, on the basis of size.
Referred specimens (seven).—Five adult males and two
adult females as follows. Kepulauan Riau: Gunung Ranai,
two adult females (MZB.Amph.26499, MZB.Amph.26503)
and five adult males (MZB.Amph.26500, MZB.Amph.26501,
MZB.Amph.26502, MZB.Amph.26504, MZB.Amph.26505).
All collected at elevations between 30 and 300 m asl.
Diagnosis.—A large species of Philautus (males ¼29.1–
34.4 SVL, n¼5; females ¼38.0–40.7 SVL, n¼2) with three
or fewer phalanges free of webbing on postaxial margin of
toe IV. Skin is smooth without tubercles on the dorsum,
upper eyelid, heel, or ventral margin of mandible. Males lack
a nuptial pad and females lack a fleshy protrusion on the
rostrum.
Comparison with Sumatran Philautus.—The large
size, lack of a fleshy rostral protrusion on adult females,
lack of a nuptial pad in males, and the lack of a row of small
conical tubercles along the ventral margin of the lower jaw
distinguishes this species from its synonym P. larutensis.
Vomerine teeth are absent; they are present in P. kerangae.
The ventral margin of the mandible is atuberculate. In P.
cornutus,P. polymorphus,andP. thamyridion there is a
distinct row of conical tubercles along the ventral margin of
the mandible. There are three or fewer phalanges free of
webbing on the postaxial side of toe IV. Philautus amabilis,
P. cornutus and P. thamyridion have more than three
phalanges free of webbing on the postaxial side of toe IV.
Males of this species lack a nuptial pad; a nuptial pad is
present in male P. refugii. The venter is unpatterned. The
venter of P. ventrimaculatus is marked by a bold dark
reticulation.
Comparison with other Sunda Shelf Philautus.—This
species is much larger than most other Philautus of the
Sunda Shelf. Vomerine teeth are absent. Vomerine teeth are
present in P. bunitus,P. hosii,P. ingeri,andP. macroscelis.
There are 3–3.25 phalanges free of webbing on the preaxial
side of toe IV. Philautus umbra has 3.75 phalanges or more
free of webbing on the preaxial side of toe IV. Philautus
amoenus,P. davidlabangi,P. jacobsoni, and P. saueri all have
2.5 or fewer phalanges on the preaxial margin of toe IV free
of webbing. The m. cutaneous pectoris is present. This
TABLE 4.—Morphological comparison between the holotype of Philautus similis and a series of adult female P. larutensis from Sumatra (n¼11).
Measurements are in millimeters. Means and standard deviations for the female P. larutensis are in the species description.
Character P. similis P. larutensis Character P. similis P. larutensis
Snout–vent length (SVL) 28.87 21.37–32.02 Protrusion on snout Yes Yes
Head length (HL) 12.15 8.59–12.72 Tubercles over eye Sparse Small, sparse
Head width (HW) 12.48 8.98–12.97 Tubercles along mandible Yes Yes
Internarial distance (IND) 2.8 2.35–3.1 Skin texture (dorsal) Smooth Mostly smooth
Eye–naris (EN) 2.71 2.1–2.78 Enlarged tubercles in
scapular region
Yes Yes
Snout length (SnL) 4.78 3.5–5.3 Calcar Small Yes, small
Interocular distance (IOD) 3.47 2.7–4 Skin texture (ventral) Granulate Areolate to
granular
Forearm length (FaL) 7.4 5.5–7.75 HL/SVL 0.42 0.39–0.43
Hand length (HnL) 8.8 7.25–9.3 HW/SVL 0.43 0.38–0.44
Thigh length (ThL) 15.74 11.72–16 HW/HL 1.03 0.95–1.06
Crus length (CrL) 16.1 12.27–16.92 IND/HL 0.23 0.21–0.27
Tarsus length (TarL) 8.55 6.7–8.8 EN/HL 0.22 0.2–0.24
Foot length (FL) 12.17 9.83–13.91 SnL/HL 0.39 0.38–0.43
Snout shape Subelliptical Subelliptical to pointed EN/SnL 0.57 0.49–0.6
Snout profile Rounded Rounded to protruding FaL/SVL 0.26 0.22–0.26
Canthus Rounded, concave Rounded, concave HnL/SVL 0.3 0.26–0.33
Lores Sloped, almost vertical Sloped to vertical HnL/FaL 1.19 1.07–1.33
Tympanum Barely discernable Indistinct to distinct ThL/SVL 0.55 0.48–0.56
Palpebral membrane Rim colored like eyelid Rim colored like eyelid CrL/SVL 0.56 0.49–0.58
Lingual papilla ? Present or absent ThL þCrL 31.84 24.17–32.51
Vomerine teeth No No ThL þCrL/SVL 1.1 0.97–1.13
Choanae shape Round, squarish Round, squarish CrL/ThL 1.02 1.02–1.15
Choanae width 0.7 0.5–0.8 TarL/SVL 0.3 0.27–0.32
Distance between choanae 2.9 2.55–2.75 FL/SVL 0.42 0.43–0.48
Tongue Bifurcate, ½ free Bifurcate ½–1
=
3free FL/TarL 1.42 1.43–1.63
Palmar tubercle Divided Divided SnL-EN 2.07 1.4–2.63
Thenar tubercle Ovoid, indistinct Ovoid, indistinct SnL-EN/HL 0.17 0.16–0.22
Dermal fringe on fingers I–IV I–IV IOD/EN 1.28 1.14–1.48
Tubercles on snout and lips No Present or absent IOD/IND 1.24 0.95–1.33
P. larutensis webbing formula P. similis webbing formula
I(1.75–2)–(2–2.5)II(1.25–1.5)–(2.5–3)III(1.5–1.75)–(2.5–3)IV(2.25–3)–(1.5–2)VI(2)–(2
þ
)II(1.25)–(3
)III(1.75)–(3)IV(2.75)–(1.5)V
89
WOSTL ET AL.—SUMATRAN PHILAUTUS
muscle is absent in P. acutus,P. aurantium,P. disgregus,P.
erythrophthalmus,P. tectus, and P. vermiculatus. Males lack
nuptial pads. Nuptial pads are present in male P. julian-
dringi,P. kakipanjang,P. mjobergi, and P. nephophilus. This
species is much larger (males ¼29.1–34.4 SVL, n¼5) than
P. aurifasciatus (males ¼16.23–21.85 SVL, n¼10) and the
two species differ in head proportions. Specifically, there is
relatively more space between the orbit and naris in P.
petersi (EN/HL ¼0.23–0.27, EN/SnL ¼0.61–0.71, n¼7)
than in P. aurifasciatus (EN/HL ¼0.16–0.22, EN/SnL ¼
0.41–0.55, n¼18).
Variation.—On the basis of five adult males and two adult
females from Great Natuna Island. SVL 29.09–34.38 (31.58
62.62), 37.98–40.74 (39.36 61.95); HL 11.57–14.05
(12.79 61.15), 15.96–17.50 (16.73 61.09); HL/SVL 0.38–
0.42 (0.40 60.02), 0.42–0.43 (0.43 60.01); HW 11.92–
13.51 (12.66 60.67), 16.47–17.31 (16.89 617.31); HW/HL
0.94–1.03 (0.99 60.04), 0.99–1.03 (1.01 60.03); IND 2.85–
3.5 (3.1 60.27), 3.44–3.83 (3.64 60.28); IND/HL 0.23–
0.25 (0.24 60.01), 0.22; EN 2.65–3.80 (3.24 60.44), 3.98–
4.51 (4.25 60.37); EN/HL 0.23–0.27 (0.25 60.02), 0.25–
0.26 (0.26 60.01); SnL 4.32–5.68 (5.12 60.57), 6.35–6.5
(6.43 60.11); SnL/HL 0.37–0.44 (0.40 60.03), 0.36–0.41
(0.39 60.04); EN/SnL 0.61–0.67 (0.63 60.03), 0.61–0.71
(0.66 60.07); IOD 3.04–3.48 (3.28 60.18), 3.64–3.74 (3.69
60.07); IOD/EN 0.92–1.15 (1.02 60.09), 0.83–0.91 (0.87
60.06); IOD/IND 0.99–1.15 (1.06 60.06), 0.98–1.06
(1.02 0.06); FaL 6.75–7.75 (7.07 60.45), 9.15–9.35 (9.25 6
0.14); FaL/SVL 0.23–0.25 (0.24 60.01), 0.24–0.25 (0.25 6
0.01); HnL 8.58–10.75 (9.57 60.90), 11.75–11.81 (11.78 6
0.04); HnL/SVL 0.28–0.31 (0.30 60.01), 0.30–0.32 (0.31 6
0.01); HnL/FaL 1.16–1.29 (1.22 60.05), 1.24–1.25 (1.25
0.01); ThL 14.80–18.37 (16.50 61.46), 21.22–21.57 (21.40
60.25); ThL/SVL 0.50–0.53 (0.52 60.01), 0.52–0.57 (0.55
60.04); CrL 16.51–19.94 (18.24 61.45), 22.98–23.02
(23.00 60.03); CrL/SVL 0.56–0.60 (0.58 60.02), 0.57–0.61
(0.59 60.03); CrL/ThL 1.08–1.13 (1.11 60.02), 1.07–1.08
(1.08 60.01); TarL 8.55–10.33 (9.41 60.67), 11.71–12.52
(12.12 60.57); TarL/SVL 0.27–0.32 (0.30 60.02), 0.29–
0.33 (0.31 60.03); FL 11.80–14.77 (13.10 61.33), 16.58–
16.65 (16.62 60.05); FL/SVL 0.40–0.43 (0.41 60.02),
0.41–0.44 (0.43 60.02); FL/TarL 1.27–1.55 (1.39 60.11),
1.33–1.42 (1.38 60.06).
The snout is subelliptical in dorsal view and rounded,
almost vertical in profile. The canthus is rounded, the loreal
region is sloped (almost vertical in one specimen). Nostrils
are round to ovoid and laterally oriented. The tympanum is
distinct with an obvious annulus. The supratympanic fold is
curved to almost straight and extends from the eye to above
the insertion of the forelimb. The pupil is horizontal. The
palpebral membrane is mostly clear centrally, the rim is
colored like the eyelid, and the pigmentation and pattern of
the adjacent skin invades the anterior and posterior margin.
There is no lingual papilla, and no vomerine teeth. Choanae
are round to ovoid and separated by 3–3.5 times their
greatest diameter. The tongue is broad, about half free, and
bifurcates posteriorly. Vocal slits are elongate and located
laterally, just medial to the rictus of the mouth.
A nuptial pad is absent. The palmar tubercle is oblong and
divided distally or completely divided lengthwise. The thenar
tubercle is ovoid. An enlarged tubercle may be present at the
distal end of metacarpals I–IV. The subarticular tubercles of
the fingers are round. There are no supernumerary
tubercles. The pads of the fingers are round to slightly
broadened and there is a distinct ungual flap. A fine dermal
fringe is present on fingers II–IV; in one individual (MZB.
Amph.26499), it was not evident on finger II. There is no
webbing between the fingers. Relative finger length is I ,II
,IV ,III.
The plantar surface is mostly smooth with small scattered
tubercles, none prominent. The outer metatarsal tubercle is
absent and the inner metatarsal tubercle is oblong and
flattened. The toe pads are round with an ungual flap. The
relative toe length is I ,II ,III V,IV. There is a
dermal fringe of toes I–V, though difficult to discern (or
absent) on toe I of some individuals. The feet are relatively
well webbed; the webbing formula is I(2)–(2–2.5)II(1.5)–
(2.5–3)III (1.5–2)–(3–3.25)IV(2.75–3)–(1.5–2)V.
The skin is relatively smooth with scattered small rounded
tubercles on the dorsum, antecubital, crus, and tarsus. There
are no tubercles on the snout or lower jaw. Tubercles on the
eyelid are indistinct and usually not visible in preserved
specimens. There is no calcar and the heel is mostly smooth
(one individual, MZB.AMPH.26504, with tiny round tuber-
cles on the heel). There is a small patch of skin inferior to the
vent with enlarged granules. The ventral surface is areolate.
The m. cutaneous pectoris is present and relatively well
developed and the pectoral septum is inserted across the
breadth of the pectoral region.
In most individuals, the venter is white and patternless.
There are tiny black flecks on the throat, best seen through
magnification. There is dusky flecking on the throat of one
individual (MZB.AMPH.26505), a male. Dorsally, specimens
are mottled brown to yellowish. The snout is distinctly lighter
in a few of the examined specimens.
Distribution and habitat.—This species is known only
from Mount Ranai on Great Natuna Island at elevations of
30–300 m asl. It is included in this paper to distinguish it
from P. larutensis, its former synonym, a widespread species
on Sumatra.
Philautus refugii Inger and Stuebing 1996
Figs. 7, 14–17, 19
Philautus refugii Inger and Stuebing 1996:544.
Philautus (Philautus)refugii Bossuyt and Dubois 2001:59
(new combination).
Philautus refugii Hertwig et al. 2012a:38 (by implication).
Holotype.—FMNH 252418. An adult male from Bukit
Lanjak, Lubok Antu District, Second Division, Sarawak,
Malaysia.
Referred specimens (eight).—Four adult males and
four adult females collected in central Sumatra as follows.
Bengkulu: Bukit Kaba, one female (UTA-A 63963,
3.491318S, 102.634978E, elev. 1366 m). Jambi: Gunung
Kunyit, one male (MZB.Amph.26144, 2.259458S,
101.49488E, elev. 1436 m). Sumatera Barat: Gunung
Talakmau, one female (UTA-A 63965, 0.10228N,
99.948228E, elev. 980 m) and one male (MZB.Amph.
26160, 0.10228N, 99.948228E, elev. 980 m). Sumatera
Utara: Gunung Sorik Merapi, one female (UTA-A 63966,
0.701648N, 99.552628E, elev. 1407 m); Kota Baringen Julu,
one female (MZB.Amph.26141, 0.665998N, 99.572178E,
elev. 1320 m) and two males (MZB.Amph.26142,
90 Herpetological Monographs 31, 2017
0.665998N, 99.572178E, elev. 1320 m; MZB.Amph.26143,
0.666368N, 99.571918E, elev. 1312 m).
Diagnosis.—A small (males ¼16.5–16.8 SVL, n¼4;
females ¼18.2–20.5 SVL, n¼4) brown species of Philautus
with relatively long legs (CrL/SVL 0.6–0.7, n¼8) and 3–3.25
phalanges of toe IV free of webbing. The preaxial surface of
the thigh is boldly patterned with white spots on a dark field.
A small nuptial pad is evident in males.
Comparison with Sumatran Philautus.—This species is
most similar to P. cornutus and P. thamyridion. There are 1.5
or fewer phalanges free of webbing on the preaxial side of
toe II. In P. cornutus and P. thamyridion there are two or
more phalanges free of webbing on the preaxial side of toe
II. Vomerine teeth are absent; they are present in P.
kerangae. Males have a nuptial pad. Male P. amabilis,P.
polymorphus,P. ventrimaculatus,andP. thamyridion do not.
Females lack a rostral protrusion, whereas a rostral
protrusion is present in female P. cornutus. Adults are
smaller (males ¼16.5–16.8 SVL, n¼4) than P. amabilis
(males ¼19.6–23.8 SVL, n¼20), P. larutensis (males ¼
20.2–25.4 SVL, n¼26), and P. polymorphus (males ¼
19.49–26.95 SVL, n¼27). Additionally, the relative crus
length (CrL/SVL ¼0.60–0.70) is greater than P. amabilis
(CrL/SVL ¼0.46–0.57) and P. polymorphus (CrL/SVL ¼
0.42–0.57). The ventral surface is dusky with indistinct
mottling, heaviest in the pectoral region. This is in in stark
contrast to P. ventrimaculatus, in which the ventral surface is
patterned with a bold dark reticulation on a light field. The
pattern on the preaxial surface of the thigh, with bold light
marks on a dark field, distinguishes this species from all
other species of Philautus on Sumatra.
Comparison with other Sunda Shelf Philautus.—This
species lacks vomerine teeth. Vomerine teeth are present in
P. bunitus,P. hosii,P. ingeri, and P. macroscelis. Approx-
imately three phalanges of toe IV are free of webbing.
Philautus acutus,P. amoenus,P. aurantium,P. davidlabangi,
P. jacobsoni,P. mjobergi,andP. saueri all have 2.5 or fewer
phalanges of toe IV free of webbing. Conversely, the pedal
webbing is more extensive than in P. umbra, which has 3.5 or
more phalanges free of webbing on toe IV. The m. cutaneous
pectoris is present. This muscle is absent in P. disgregus,P.
erythrophthalmus,P. tectus, and P. vermiculatus. Males
possess a nuptial pad. Male P. acutus,P. bunitus,P.
davidlabangi,P. ingeri,P. hosii,P. kerangae,P. petersi,
and P. vermiculatus lack a nuptial pad. This species is smaller
than P. kakipanjang (males ¼21.2–23.7 SVL; Dehling and
Dehling 2013) and the distinct pattern on the preaxial
surface of the thigh of white spots on a dark field separates
this species from P. juliandringi,P. kakipanjang, and P.
nephophilus. The crus (CrL/SVL 0.6–0.7, n¼8) is relatively
longer than in P. aurifasciatus (CrL/SVL ¼0.49–0.57, n¼
17).
Variation.—On the basis of four adult males and four
adult females from Sumatra. SVL 16.45–16.82 (16.65 6
0.15), 18.19–20.45 (19.33 61.06); HL 6.20–6.90 (6.67 6
0.32), 8.04–8.48 (8.29 60.21); HL/SVL 0.37–0.42 (0.40 6
0.02), 0.41–0.45 (0.44 60.02); HW 5.96–6.31 (6.13 60.16),
7.07–7.85 (7.39 60.29); HW/HL 0.87–1.00 (0.92 60.06),
0.88–0.93 (0.89 60.01); IND 1.55–1.95 (1.81 60.19), 2.07–
2.45 (2.20 60.10); IND/HL 0.23–0.31 (0.27 60.03), 0.25–
0.29 (0.27 60.02); EN 1.40–1.55 (1.48 60.06), 1.54–2.00
(1.61 60.11); EN/HL 0.21–0.25 (0.23 60.02), 0.18–0.24
(0.19 60.02); SnL 2.57–2.8 (2.71 60.09), 2.98–3.60 (3.16
60.17); SnL/HL 0.38–0.44 (0.40 60.03), 0.37–0.42 (0.38
60.02); IOD 1.90–2.10 (1.98 60.09), 2.18–2.40 (2.22 6
0.04); IOD/EN 1.27–1.38 (1.33 60.04), 1.20–1.44 (1.38 6
0.08); IOD/IND 0.97–1.24 (1.10 60.11), 0.98–1.05 (1.00 6
0.03); FaL 3.65–4.10 (3.80 60.20), 4.50–5.15 (4.73 60.36);
FaL/SVL 0.22–0.24 (0.23 60.01), 0.24–0.26 (0.25 60.01);
HnL 4.40–5.01 (4.68 60.25), 5.25–5.50 (5.38 60.12); HnL/
SVL 0.0.27–0.30 (0.28 60.01), 0.28–0.30 (0.29 60.01);
HnL/FaL 1.20–1.29 (1.23 60.04), 1.07–1.20 (1.14 60.07);
ThL 7.46–9.29 (8.65 60.84), 11.05–12.18 (11.53 60.58);
ThL/SVL 0.45–0.56 (0.52 60.05), 0.59–0.62 (0.60 60.02);
CrL 9.94–10.48 (10.18 60.28), 12.49–13.51 (12.94 60.52);
CrL/SVL 0.60–0.63 (0.61 60.02), 0.65–0.70 (0.68 60.01);
CrL/ThL 1.13–1.33 (1.19 60.10), 1.10–1.13 (1.12 60.01);
TarL 5.55–6.05 (5.73 60.23), 6.80–7.55 (7.06 60.41);
TarL/SVL 0.33–0.36 (0.35 60.01), 0.34–0.38 (0.37 60.01);
FL 7.05–7.80 (7.50 60.33), 9.20–10.10 (9.42 60.33); FL/
SVL 0.42–0.47 (0.45 60.02), 0.49–0.51 (0.50 60.01); FL/
TarL 1.23–1.38 (1.31 60.06), 1.30–1.44 (1.33 60.03).
The snout is pointed to subelliptical in dorsal view and
rounded to acute in profile. The canthus rostralis is rounded
to angular and slightly concave. The loreal region is sloped.
The rostrum of females has a slight protrusion. The nostril is
small, round, and laterally oriented.
The tympanum is indistinct and covered by skin the same
color and texture as the surrounding region. The tympanic
annulus is present. A low supratympanic fold curves from the
posterior margin of the eye to just above the posterior
margin of the mandible. The pupil is horizontal. Palpebral
membrane is mostly clear centrally. There is a thin band of
pigment the color of the eyelid along the rim of the palpebral
membrane and the lower half is speckled with pigmentation.
There is no lingual papilla and no vomerine teeth. The
choanae are oval and separated by 3.5–5.5 times their
greatest diameter. The tongue is bifurcated posteriorly, with
the bifurcated portion making up 15–20% of the tongue
length.
A small nuptial pad is present on the preaxial and dorsal
surface of the first phalanx of the first finger in males. The
palmar tubercle is round to oblong and indistinct. The
thenar tubercle is ovoid and indistinct. The subarticular
tubercles of the hand are round and flat. Some individuals
have tiny indistinct supernumerary tubercles on the first
phalanx of finger III. The toe pads are entire and round to
broadened with a distinct ungual flap. There is a slight fringe
of skin on the margins of fingers I–IV that extends to the
discs; it is occasionally not evident on finger I. Relative finger
length is I ,II ,IV ,III.
The plantar surface has numerous small tubercles. The
inner metatarsal tubercle is elongate and flattened. The
subarticular tubercles are round. The proximal subarticular
tubercle of toe IV is absent. There are tiny supernumerary
tubercles on the first phalanx of toes III and IV in some
individuals. The toe pads are round to broadened and entire.
Relative toe length is I ,II ,III ¼V,IV. A fringe of skin
is present on the margin of each toe and extends to the disk.
The webbing formula is I(1.5–2)–(2–2.25)II(1.25–1.5)–(2.5–
3)III(1.5–2)–(3–3.25)IV(3–3.25)–(1.5–2)V.
There is a small tubercle on the rostrum of females.
Distinct conical tubercles are on each eyelid and a row of
small tubercles extends the length of the mandible. The
91
WOSTL ET AL.—SUMATRAN PHILAUTUS
dorsum is tuberculate with enlarged tubercles in the
postoccipital and supratympanic region that converge
posteriorly to form a V shape. The tubercles on the thigh
are sparse and occur mostly within the dark pigmented
bands. Tubercles on the crus are well spaced and arranged in
a row on the postaxial side. A small calcar may be present;
otherwise, the heel has several tiny round tubercles. A row of
small tubercles extends along the postaxial margin of the
tarsus and onto the postaxial margin of the metatarsal and
toe V. The ventral surface is granular, weakly granular under
the throat.
Specimens are predominantly brown, usually with pat-
terning of darker brown in the form of narrow bands on the
antecubital, thigh, and crus. There is usually at least an
indication of a forward-pointing V mark that originates
lateral to the sacral humps and terminates mid-dorsally near
the scapulae. This mark is often bordered anteriorly with a
thin light line. The tympanic region is dark brown and the
supratympanic fold is light. There is a black mark that
surrounds the vent and the postaxial margin of the tarsus is
dark. The dark coloration on the tarsus usually does not
extend onto the plantar surface. The preaxial surface of the
thigh and inguinal area is distinctly patterned, with light
spots on a dark background. The two specimens from
Gunung Talakmau (UTA-A 63965 and MZB.Amph.26160)
are unique in the dorsal surface of the head being bright
yellow/orange. Ventrally, specimens are beige–gray–yellow-
ish, darker under the throat. There is usually dark flecking on
the throat and pectoral region, sometimes quite dense.
Distribution and habitat.—This species occurs on both
Sumatra and Borneo. We have encountered this species in
several widely scattered localities in central and southern
Sumatra at elevation between 980 and 1429 m asl. We have
found it in sympatry with P. larutensis and P. thamyridion.
On Bukit Kaba it occurs at slightly lower elevations than P.
polymorphus. In all areas, it is found in mature forest.
New Species
Philautus amabilis sp. nov.
Figs. 10, 14–17, 19
Holotype.—MZB.Amph.26879. An adult male from Bur
Ni Telong, Kabupaten Bener Meriah, Aceh Province,
Sumatra 04.771378N, 96.810268E, 1977 m asl. Collected on
7 August 2015 by EW, Panupong Thammachoti, Ilham
Fonna, and Ahmed Muammar Kadafi at 04.771378N,
96.810268E, 1977 m asl.
Paratypes (12).—Twelve adult males (MZB.Amph.
26874, UTA-A 63804, UTA-A 63805, MZB.Amph.26875,
UTA-A 63806, MZB.Amph.26877, UTA-A 63807, UTA-A
63808, UTA-A 63809, MZB.Amph.26880, UTA-A 63810,
MZB.Amph.26881) collected with the holotype.
Referred specimens (eight).—In addition to the type
series, we examined seven adult males and a single adult
female as follows. Sumatera Barat: Gunung Marapi, one
female (MZB.Amph.26887, 0.394718S, 100.425258E, elev.
1550 m) and six males (MZB.Amph.26889, 0.394538S,
100.426618E, elev. 1587 m; UTA-A 63811 and
MZB.Amph.26890, 0.394588S, 100.426978E, elev. 1592 m;
UTA-A 63813 and MZB.Amph.26892, 0.394038S,
100.428588E, elev. 1636 m; UTA-A 63815, 0.394268S,
100.427818E, elev. 1614 m). Sumatera Utara: Gunung
Sibuatan, one male (UTA-A 63816, 2.908598N, 98.449898E,
elev. 1932 m).
Diagnosis.—A moderate-sized (males ¼19.6–23.8 SVL,
n¼20; female ¼22.5 SVL, n¼1) species that lacks strongly
developed tubercles on the eyelids, antecubital, crus, and
tarsus. Males lack a nuptial pad and females lack a rostral
tubercle.
Comparison with Sumatran Philautus.—On Sumatra
this species is most similar to P. larutensis and P.
polymorphus. Males of this species lack nuptial pads; nuptial
pads are present in male P. larutensis. Females lack the
upturned rostral protrusion, which is present in adult female
P. larutensis. This species can appear very similar to P.
polymorphus. That species has prominent (almost spikelike)
tubercles on the eyelids and is much more tuberculate
overall, usually with well-developed tubercles on the
postorbital region, suprascapular region, antecubital, crus,
and tarsus. Philautus amabilis is largely atuberculate. When
present, tubercles are low, sparse, and rounded. In P.
amabilis, the pectoral septum is broad and inserts onto the
skin across the breadth of the pectoral region. The pectoral
septum of P. polymorphus is reduced to a narrow band that
inserts just onto the skin overlying the sternum. Vomerine
teeth are absent, but present in P. kerangae. There are 3.25
phalanges free of webbing on the preaxial side of toe IV.
Philautus cornutus and P. thamyridion have 3.5 or more
phalanges free of webbing on the preaxial margin of toe IV.
This species is larger (males ¼19.6–23.8 SVL, n¼20) than
P. refugii (males ¼16.5–16.8 SVL, n¼4) and P.
ventrimaculatus (males ¼15.04–18.6 SVL, n¼15). The
preaxial surface of the thigh is unpatterned. The preaxial
surface of the thigh in P. refugii is distinctly patterned with
light spots on a dark field. The venter of P. amabilis is not
distinctly patterned, whereas P. ventrimaculatus has a
distinctive bold reticulum on the venter.
Comparison with other Sunda Shelf Philautus.—This
species lacks vomerine teeth. Vomerine teeth are present in
P. bunitus,P. hosii,P. ingeri, and P. macroscelis. The
webbing on toe IV, with three or more phalanges free of
webbing, is less extensive than on P. acutus,P. amoenus,P.
aurantium,P. davidlabangi,P. jacobsoni,P. mjobergi,andP.
saueri, which have 2.5 or fewer phalanges free of webbing.
The webbing on toe IV is more extensive than in P. umbra,
which has 3.5 or more phalanges free of webbing. The m.
cutaneous pectoris is present in this species. It is absent in P.
amoenus,P. aurantium (and presumably P. gunungensis), P.
disgregus,P. erythrophthalmus,P. tectus, and P. vermic-
ulatus. Males lack a nuptial pad. A nuptial pad is present in
male P.amoenus,P. juliandringi,P. kakipanjang,P. mjobergi,
P. nephophilus,andP. tectus. Females lack a rostral
protrusion. A rostral tubercle is present in female P.
aurifasciatus. This species is much smaller (males ¼19.6–
23.8 SVL, n¼20) than P. petersi (males ¼29.1–34.4 SVL, n
¼5).
Description of holotype.—SVL 20.79; HL 8.13; HW
7.15; IND 1.95; EN 1.59; snout length 3.15; IOD 2.45; FaL
4.80; HnL 6.45; ThL 10.56; CrL 10.67; TarL 6.35; FL 9.75.
Head 39% of SVL; HW 38% of SVL, head slightly
narrower than long (HW/HL ¼0.97); IOD greater than EN
(IOD/EN 1.55) and wider than IND (IOD/IND ¼1.26);
nostril small, round, and dorsolaterally oriented; snout
subelliptical in dorsal view, rounded in profile; canthus
92 Herpetological Monographs 31, 2017
FIG. 10.—Philautus amabilis. MZB.Amph.26879, holotype, male, 20.79 mm snout–vent length (SVL), Bur Ni Telong Aceh (A and B). MZB.Amph.26887,
female, 22.46 mm SVL, Gunung Marapi, Bengkulu (C and D). UTA-A 63816, male, 20.64 mm SVL, Gunung Sibuatan, Sumatera Utara (E and F). A color
version of this figure is available online.
93
WOSTL ET AL.—SUMATRAN PHILAUTUS
rostralis rounded and curved medially; loreal region sloping;
tympanum overlain with skin the same color and texture as
the surrounding area and barely discernable, annulus not
visible; supratympanic fold slight, extending from eye to
insertion of forelimb; pupil horizontal; palpebral membrane
clear except for thin band of broken pigmentation along rim
and tiny specks of black pigmentation most prevalent
anteriorly and posteriorly; lingual papilla absent; vomerine
teeth absent; choanae small, round, separated by about 6.25
times their greatest diameter; tongue broad, bifurcate
posteriorly, about half of length free, each bifurcation
approximately one-fifth of total length.
Forearm 23% of SVL; hand 31% of SVL, 134% of
forearm; palmar tubercle round and indistinct; thenar
tubercle indistinct; subarticular tubercles of hands round,
flat; supernumerary tubercle flat, faint, immediately distal to
metacarpal/phalangeal articulation of finger III; pads of
fingers entire, round; distinct ungual flap present; dermal
fringe thin and on fingers III and IV to disc; rudimentary
fleshy webbing between fingers II–IV; relative finger length I
,II ,IV ,III.
Thigh 51% of SVL; crus 51% of SVL and as long as thigh
(CrL/ThL ¼1.01); tarsus 31% of SVL; foot 47% of SVL and
154% of TarL; small distinct tubercle at the base of the
fourth metatarsal; inner metatarsal tubercle flat and oblong;
subarticular tubercles of foot round; proximal subarticular
tubercle of toe IV absent; proximal subarticular tubercles of
toes III and V reduced; supernumerary tubercle tiny and flat,
one on first phalanx of toe IV; toe pads entire and round,
about same size as finger pads; ungual flap of toes present;
relative toe length I ,II ,III ¼V,IV; very slight dermal
fringe to disc on toes II–V; webbing formula I2–2
þ
II2
3.25III2–3.25IV3.25–2
þ
V.
Dorsal surface of snout anterior to eyes without tubercles;
rostral tubercle absent; eyelids with few weakly developed
conical tubercles; row of tubercles along margin of mandible
present but faint; dorsal surface of trunk and thigh smooth;
enlarged tubercles in postorbital, supratympanic, and
suprascapular regions reduced to low ridges; antecubital
with small conical tubercles, especially on postaxial side;
thighs, crus, and tarsus smooth dorsally with a few very small
conical tubercles; calcar absent, some small round tubercles
on heel; patch of enlarged granules inferior to vent,
extending to ventral surface and laterally onto postaxial
surface of thighs; skin on venter granular, weakly areolate
under throat, weakly granular under thighs; m. cutaneous
pectoris present but thin; pectoral septum a broad sheet that
extends across the pectoral region.
Overall, the holotype is light brown dorsally. There are
broad, slightly darker bands on the forearm, thigh, crus,
tarsus, and outer digits. Bands present, but poorly delimited
on the legs. There is a faint rust-red streak mid-dorsally and
ill-defined blotches of the same color on the thighs, crus,
toes, and outer fingers. The tympanic and loreal regions are
the same color as the bands on the forearm. The supra-
tympanic fold is slightly darker and bordered above by a thin
light line. On each flank, there are several small yellow-green
flecks. The preaxial surface of the thigh is unpatterned and
off white. Ventrally, the specimen is light with dusky flecks.
These flecks are most prominent in the pectoral region and
laterally where they fuse to form a slight reticulation. The
flecking on the venter extends dorsally onto the sides behind
the axilla. The iris is bicolored, golden with a bold wedge of
dark brown pigmentation anterior and posterior to the pupil.
In conjunction with the pupil, these dark patches create a
dark horizontal band across the eye. The light portions of the
eye are patterned with a dark vermiculation.
Variation.—On the basis of 20 adult males and a single
adult female from Sumatra. SVL 19.56–23.75 (21.18 60.95),
22.46; HL 7.85–9.57 (8.62 60.39), 8.92; HL/SVL 0.39–0.42
(0.41 60.01), 0.40; HW 7.85–9.29 (8.46 60.39), 8.61; HW/
HL 0.93–1.02 (0.98 60.02), 0.97; IND 1.78–2.25 (1.94 6
0.12), 2.15; IND/HL 0.21–0.25 (0.23 60.01), 0.24; EN
1.51–2.03 (1.74 60.14), 1.76; EN/HL 0.18–0.22 (0.20 6
0.01), 0.20; SnL 2.93–3.59 (3.29 60.16), 3.46; SnL/HL
0.36–0.39 (0.38 60.01), 0.39; IOD 2.11–2.68 (2.40 60.12),
2.30; IOD/EN 1.22–1.61 (1.39 60.10), 1.31; IOD/IND
1.16–1.35 (1.25 60.06), 1.08; FaL 4.80–5.50 (5.18 60.18),
6.00; FaL/SVL 0.22–0.27 (0.25 60.01), 0.27; HnL 6.00–7.15
(6.57 60.29), 7.05; HnL/SVL 0.28–0.34 (0.31 60.02), 0.31;
HnL/FaL 1.13–1.39 (1.27 60.06), 1.18; ThL 10.20–11.08
(10.40 60.41), 12.35; ThL/SVL 0.45–0.53 (0.49 60.02),
0.55; CrL 10.20–11.18 (10.62 60.31), 12.84; CrL/SVL 0.46–
0.54 (0.50 60.02), 0.57; CrL/ThL 0.98–1.10 (1.02 60.03),
1.04; TarL 5.50–6.35 (5.90 60.27), 7.10; TarL/SVL 0.25–
0.31 (0.28 60.02), 0.32; FL 9.30–10.40 (9.75 60.28), 10.9;
FL/SVL 0.41–0.50 (0.46 60.02), 0.49; FL/TarL 1.54–1.75
(1.65 60.07), 1.54.
In most specimens examined, the snout is subelliptical in
dorsal view; however, it is slightly truncate in some
individuals. In one individual, a male (UTA-A 63816), there
is a tiny elongate tubercle at the tip of the snout, forming a
small keel.
The proximal subarticular tubercles of fingers III and IV
are often indistinct or absent. They are frequently displaced
distally, blurring the distinction between subarticular tuber-
cle and supernumerary tubercle. In several individuals, there
is a small distinct tubercle at the distal end of the third or
fourth metacarpal, just proximal to the metacarpal/phalan-
geal articulation. Supernumerary tubercles are absent or
occur on the proximal phalanx of finger III, finger IV, or
both. When present, they are immediately distal to the
metacarpal–phalangeal articulation and are faint. The palmar
tubercle is small, elongate, often faint, and occasionally
divided horizontally. The accessory palmar tubercle is
frequently missing.
On the plantar surface there are one to two small
tubercles at the base of the fourth metatarsal; these are faint
in about one-half of the examined specimens. There is
usually a faint supernumerary tubercle at the base of toe IV
or toe V. Foot webbing formula I(2)–(2
þ
–2.5)II(1.25–2)–(3–
3.25)III(2–2.25)–(3.25)IV(3
–3.5)–(2
–2
þ
)V.
We observed tubercles along the ventral margin of the
mandible in five of the specimens examined (MZB.Amph.
26879, MZB.Amph.26881, UTA-A 63805, UTA-A 63812,
UTA-A 63814) and light spots that may represent tubercles
in two (UTA-A 63804 and UTA-A 63806). In all cases when
they are detectable, the tubercles are small and faint. The
forearm is smooth or bears small conical tubercles. The heel
is usually smooth, though in a few individuals there are
several small round tubercles.
Dorsally, this species ranges from light brown to pinkish.
The species can be uniformly colored or mottled with darker
flecks. Several individuals were flecked with light green. The
94 Herpetological Monographs 31, 2017
flecking can be extensive, especially laterally. Some individ-
uals are striped. The stripe can be broad, covering the top of
the head and extending to the vent, or a thin bright white–
yellow stripe on the dorsum, thigh, and crus. Most
individuals lack distinct darker bands on the limbs. One
juvenile (MZB.Amph.26878) is boldly patterned with dark
bands on the thighs, crus, and tarsus. This same specimen
has a dark ‘‘)(’’ shaped mark on the dorsum.
Ventrally, the color ranges from yellow/orange to white
and can be unpatterned or darkly flecked. The flecking is
usually most prominent on the pectoral region, lateral sides
of the anterior abdomen, and margin of the jaw. The preaxial
surface of the thigh lacks pattern and is white to yellow/
orange.
Vocalization.—The call is a series of short rasping chirps
each consisting of a single pulsed note 20–50 s apart but
occasionally given in a rapid series of three to seven notes.
Each note lasts 0.031–0.056 s. Within a call, the note length
is constant. The fundamental frequency of the call ranges
between 1248.93 and 1335.06 Hz and dominant frequency of
the call is 2497.85–2670.12 Hz. Each note is composed of
four to seven pulses. The first two to three pulses are
distinct, but the latter merge into each other. The call is
weakly frequency modulated with a weak harmonic at four
times the fundamental frequency. Unedited recordings of
the call are available to listen to or download at the Cornell
Lab of Ornithology Macaulay Library (available at http://
macaulaylibrary.org/) under catalog numbers 219800 and
219801.
Etymology.—The name amabilis is a masculine adjective
from Latin meaning lovely. It is an apt description of this
charming species.
Distribution and habitat.—We collected P. amabilis
from Gunung Merapi, Sumatera Barat Province; Gunung
Sibuatan, Sumatera Utara Province; and Bur Ni Telong,
Aceh Province. It occurs at elevations above 1825 m asl in
Sumatera Utara and Aceh Province. In Sumatera Barat this
species was found at lower elevation (1550–1636 m asl). On
Gunung Sibuatan and Bur Ni Telong it is narrowly allopatric
with P. larutensis. At both localities, this species was found at
slightly higher elevations and we did not detect any overlap
in the elevational distribution of the two species. On Gunung
Merapi, where we did not observe P. larutensis, this species
is sympatric with P. polymorphus. In all instances, we
collected this species in dense forest. The habitat on Gunung
Sibuatan consists of a stunted, windblown, moss-covered
forest where males called from 2–5 m up in the trees.
Elsewhere it inhabited typical, tall montane forest and we
found males calling (usually from leaves) 0.5–3.0 m above
the ground.
Philautus polymorphus sp. nov.
Figs. 11, 14–19
Holotype.—MZB.Amph.26789. An adult male from
Gunung Patah, Kabupaten Maura Enim, Sumatera Selatan
Province, Sumatra 04.225958S, 103.416238E, 2052 m asl.
Collected on 12 July 2015 by EW and Goutam Sarker.
Paratypes.—Ten adult males (UTA-A 63943,
MZB.Amph.26790, UTA-A 63944, UTA-A 63945, UTA-A
63946, MZB.Amph.26793, UTA-A 63947, UTA-A 63948,
MZB.Amph.26797, and UTA-A 63949) collected with the
holotype.
Referred specimens (42).—In addition to the type
series we examined 16 adult males and 26 adult females as
follows. Bengkulu: Bukit Kaba, three females (MZB.Amph.
26811, 3.507958S, 102.628868E, elev. 1828 m; UTA-A 63900
and MZB.Amph.26814, 3.507278S, 102.629848E, elev. 1800
m) and two males (MZB.Amph.26810, 3.507958S,
102.628868E, elev. 1828 m; UTA-A 63901, 3.507278S,
102.629848E, elev. 1800 m); Gunung Kambing, seven
females (MZB.Amph.26858 and UTA-A 63910, 3.396118S,
102.636288E, elev. 1634 m; UTA-A 63913 and
MZB.Amph.26861, 3.394278S, 102.637358E, elev. 1673 m;
MZB.Amph.26863, 3.393688S, 102.638038E, elev. 1699 m;
UTA-A 63915, 3.397218S, 102.634858E, elev. 1606 m;
MZB.Amph.26864, 3.399468S, 102.633128E, elev. 1532 m)
and one male (MZB.Amph.26859, 3.394278S, 102.637358E,
elev. 1673 m); Gunung Daun, two females (UTA-A 63905,
3.363668S, 102.383258E, elev. 1747 m; UTA-A 63907,
3.359658S, 102.383058E, elev. 1663 m) and two males
(UTA-A 63906, 3.363668S, 102.383258E, elev. 1747 m;
MZB.Amph.26855, 3.359658S, 102.383058E, elev. 1663 m).
Jambi: Gunung Kerinci, four females (UTA-A 63916,
1.747178S, 101.259358E, elev. 1816 m; MZB.Amph.26755
and MZB.Amph.26756, 1.74578S, 101.258448E, elev. 1838
m; MZB.Amph.26761, 1.738248S, 101.25988E, elev. 1953 m)
and two males (UTA-A 63919 and UTA-A 63920, 1.740948S,
101.259148E, elev. 1907 m); vicinity of Danau Tujuh, three
females (UTA-A 63923, 1.709748S, 101.370898E, elev. 1549
m; UTA-A 63924, 1.708988S, 101.371248E, elev. 1575 m;
MZB.Amph.26762, 1.70878S, 101.371428E, elev. 1581 m).
Lampung: vicinity of Ngarip, two females (MZB.Amph.
26751, 5.279698S, 104.557568E, elev. 1441 m; UTA-A 63926,
5.28188S, 104.557678E, elev. 1358 m) and two males (MZB.
Amph.26747, 5.280698S, 104.556898E, elev. 1404 m;
MZB.Amph.26748, 5.280018S, 104.557468E, elev. 1438 m);
vicinity of Ranau Danau, three males (UTA-A 63925,
MZB.Amph.26752, and MZB.Amph.26750, 4.941698S,
103.853578E, elev. 1337 m). Sumatera Barat: Gunung
Marapi, two females (MZB.Amph.26888, 0.394718S,
100.425258E, elev. 1550 m; UTA-A 63940, 0.394268S,
100.427818E, elev. 1614 m) and two males (UTA-A 63931,
0.395148S, 100.424558E, elev. 1529 m; UTA-A 63934,
0.394718S, 100.425258E, elev. 1550 m). Sumatera Selatan:
Gunung Dempo, two females (MZB.Amph.26823,
4.036258S, 103.143518E, elev. 2037 m; MZB.Amph.26827,
4.03818S, 103.145788E, elev. 1924 m) and two males (UTA-A
63953 and MZB.Amph.26825, 4.036258S, 103.143518E, elev.
2037 m); Gunung Pesagi, one female (MZB.Amph.26759,
4.905528S, 104.132068E, elev. 1547 m).
Diagnosis.—This is a moderate-sized to large Philautus
(males ¼19.5–27.0 SVL, n¼27; females ¼22.0–28.9 SVL n
¼26) with prominent conical tubercles on the eyelids, well-
developed tubercles on the crus, approximately three
phalanges of the fourth toe free of webbing, adult males
without nuptial pads, and adult females without an enlarged
tubercle on the snout. Coloration and pattern are highly
variable, though there is usually a thin light vertical line on
the rostrum.
Comparison with Sumatran Philautus.—This species is
most similar to P. amabilis and P. larutensis. Adult males lack
a nuptial pad and adult females lack a rostral protrusion.
95
WOSTL ET AL.—SUMATRAN PHILAUTUS
FIG. 11.—Philautus polymorphus. MZB.Amph.26789, holotype, male 25.30 mm snout–vent length (SVL), Gunung Patah, Sumatera Selatan (A).
MZB.Amph.26755, female, 25.89 mm SVL, Gunung Kerinci, Jambi (B). UTA-A 63953, female 28.93 mm SVL, Gunung Dempo, Sumatera Selatan (C). UTA-
A 63935, male, 21.28 mm SVL, Sumatera Barat Province, Gunung Marapi (D). MZB.Amph.26814, female, 26.04 mm SVL, Bukit Kaba, Bengkulu (E). UTA-
A 63909, female, 23.02 mm SVL, Gunung Daun, Bengkulu (F). A color version of this figure is available online.
96 Herpetological Monographs 31, 2017
These are present in P. larutensis. This species is more
tuberculate than P. amabilis, with prominent tubercles on
the eyelids and dorsal surface of the antecubital, crus, and
tarsus. When present in P. amabilis, these tubercles are low,
rounded, and sparse. Furthermore, it differs from P.
amabilis in the nature of the pectoral septum. In P.
polymorphus the pectoral septum is a thin medial band that
inserts only onto the skin immediately superficial to the
sternum. In P. amabilis, the pectoral septum is broad and
inserts across the breadth of the pectoral region. This species
lacks vomerine teeth; they are present in P. kerangae. There
are 3.5 or fewer phalanges on the preaxial side of toe IV free
of webbing. Philautus cornutus and P. thamyridion have 3.5
phalanges or more free of webbing. The crus (CrL/SVL ¼
0.42–0.57, n¼53 in) is relatively shorter than in P. refugii
(CrL/SVL ¼0.60–0.70, n¼8 in) and P. cornutus (CrL/SVL
¼0.59–0.66, n¼5). The snout is rounded in profile. The
snout is protruding to acute in P. cornutus and P. refugii.
Philautus polymorphus is larger (males ¼19.5–27.0 SVL, n
¼27) than P. refugii (males ¼16.4–16.8 SVL, n¼4) and P.
ventrimaculatus (males ¼15.0–18.6, n¼15) and lacks the
distinctive pattern that is on the anterior surface of the thigh
in P. refugii or the ventral surface of P. ventrimaculatus.
Comparison with other Sunda Shelf Philautus.—This
species lacks vomerine teeth, which are present in P.
bunitus,P. hosii,P. ingeri,andP. macroscelis. There are
between 3 and 3.5 phalanges free of webbing on toe IV.
There are 2.5 or fewer phalanges of toe IV free of webbing in
P. acutus,P. amoenus,P. aurantium,P. davidlabangi,P.
jacobsoni, and P. saueri. The pedal webbing on toe V, with
two or fewer phalanges free of webbing, is more extensive
than in P. umbra, which has 2.6 phalanges free. Males lack a
nuptial pad. A nuptial pad is present in male P. amoenus,P.
juliandringi,P. kakipanjang,P. mjobergi,P. nephophilus,
and P. tectus. The eye of P. erythrophthalmus is red-orange
and the eyelid is free of tubercles. Philautus polymorphus is
smaller (males ¼19.5–27.0 SVL, n¼27) than P. petersi
(males ¼29.1–34.4 SVL, n¼5) and has distinct tubercles on
the eyelid. Females of this species lack a rostral tubercle,
which is present in female P. aurifasciatus.Philautus
disgregus has a distinctly pigmented lower eyelid. The lower
eyelid of P. polymorphus is unpigmented except for a thin
band along the rim.
We are unable to distinguish this species from P.
vermiculatus from Peninsular Malaysia. Dring (1987)
describes the iris of P. vermiculatus as silver to gray. This
would be in stark contrast to the iris pattern seen in most P.
polymorphus, gold to bronze with loose dark vermiculation
and the anterior and posterior quarter pigmented dark
brown. The two species are genetically distinct.
Description of holotype.—SVL 25.30; HL 9.20; HW
9.73; IND 2.43; EN 1.73; SnL 3.61; IOD 2.99; FaL 5.90;
HnL 8.05; ThL 11.45; CrL 11.87; TarL 6.75; FL 11.25.
HL 36% of SVL; head wider than long (HW/HL ¼1.06);
IOD greater than EN (IOD/EN ¼1.73) and IND (IOD/
IND ¼1.23); nostril small, round, laterally oriented, closer
to tip of snout than to eye; snout subelliptical in dorsal view
and rounded in profile; canthus rostralis rounded and
concave; loreal region sloped; lips angled out from lores;
tympanum visible, covered in skin the same color and texture
as the surrounding area, annulus present, superior margin
covered by supratympanic fold; supratympanic fold low,
extends from posterior margin of eye to just above posterior
margin of mandible; pupil horizontal; palpebral membrane
clear with thin band of pigmentation the same color as the
eyelid along rim; lingual papilla absent; vomerine teeth
absent; choanae small, slightly elongate, and widely spaced,
space between choanae about four times greater than
diameter of choanae; tongue bifurcate posteriorly, approx-
imately half free, each bifurcation about one-quarter of total
length.
Forearm 23% of SVL; hand 32% of SVL, 136% of
forearm; nuptial pad absent; palmar surface tuberculate and
wrinkled; palmar tubercle round, flattened and indistinct;
thenar tubercle indistinct; tubercle intermediate to palmar
and thenar tubercle; subarticular tubercles round; supernu-
merary tubercle at the base of finger III immediately distal to
phalangeal/metacarpal articulation; finger pads entire,
broadened; ungual flap present on all fingers; dermal fringe
on fingers II–IV and postaxial margin of finger I to disk;
webbing between fingers II–IV, slight; relative finger length
I,II ,IV ,III.
Thigh is 45% of SVL; crus 47% of SVL, 104% of ThL;
tarsus 27% of SVL; foot 44% of SVL and 167% of TarL;
plantar tubercles numerous, tiny, spread across plantar
surface; small distinct tubercle at base of fourth metatarsal;
inner metatarsal tubercle ovoid; subarticular tubercles round
and flat, proximal subarticular tubercle of toe IV absent;
supernumerary tubercles absent; toe pads entire, slightly
broadened, a little smaller than finger pads; ungual flap
present on all toes; dermal fringe to disc on toes II–V;
relative toe length I ,II ,3¼5,4; webbing formula I2–
2.25II2
–3
þ
III2–3
þ
IV3–2
V.
Dorsal surface of snout anterior to eyes and lips with
small tubercles; rostral tubercle absent; eyelid with large
distinct conical tubercles; row of small conical tubercles
along ventral margin of mandible; enlarged tubercles in the
postorbital, supratympanic, and suprascapular regions; those
in the postorbital and suprascapular regions converge
posteriorly to form a V shape; dorsal surface of hand,
antecubital, trunk, thigh, crus, tarsus, and foot with distinct
tubercles; postaxial margin of tarsus and foot with row of
enlarged tubercles; calcar absent; heel with indistinct round
tubercles; small patch of granular skin between vent and
ventral surface; ventral skin granular on throat, pectoral
region, abdomen, and thighs; m. cutaneous pectoris absent;
pectoral septum reduced to a thin medial band that only
inserts narrowly ventral to the sternum.
The holotype is predominantly brown dorsally, lighter on
the flanks, with dark brown flecks. The hand, antecubital,
thigh, crus, tarsus, and foot are banded with darker brown.
There is a dark-brown interorbital bar and poorly defined
bars on the lips. The trunk is patterned with a dark-brown
hyperbola, )(, and mid-dorsally there is a row of dark-brown
irregular blotches. The supratympanic fold is also dark
brown. The flanks are washed in green below the hyperbola.
The eyelids, thigh, and crus have irregular green blotches.
The region between the eye and rictus is marked with a wavy
light suborbital bar. The specimen is light gray ventrally with
a peppering of dusky flecks.
Variation.—On the basis of 27 adult males and 26 adult
females from Sumatra. SVL 19.46–26.95 (23.12 62.15),
21.98–28.93 (25.49 62.04); HL 7.99–10.30 (9.29 60.65),
8.79–11.78 (10.15 60.69); HL/SVL 0.36–0.43 (0.40 60.02),
97
WOSTL ET AL.—SUMATRAN PHILAUTUS
0.37–0.43 (0.40 60.02); HW 8.11–10.79 (9.36 60.86),
8.70–11.70 (10.23 60.76); HW/HL 0.95–1.11 (1.01 60.04),
0.96–1.06 (1.02 60.03); IND 1.95–2.60 (2.28 60.18), 2.25–
2.80 (2.48 60.12); IND/HL 0.23–0.27 (0.25 60.01), 0.21–
0.26 (0.24 60.01); EN 1.59–2.12 (1.85 60.14), 1.60–2.44
(2.04 60.19); EN/HL 0.18–0.21 (0.20 60.01), 0.18–0.22
(0.20 60.01); SnL 3.19–4.23 (3.64 60.26), 3.35–4.72 (4.01
60.32); SnL/HL 0.37–0.42 (0.39 60.01), 0.36–0.42 (0.39 6
0.01); IOD 2.26–3.09 (2.66 60.22), 2.30–3.16 (2.82 60.20);
IOD/EN 1.20–1.73 (1.44 60.13), 1.20–1.59 (1.39 60.10);
IOD/IND 0.99–1.28 (1.17 60.08), 1.00–1.23 (1.13 60.06);
FaL 5.00–6.95 (5.95 60.50), 5.75–8.05 (6.08 60.55); FaL/
SVL 0.23–0.28 (0.26 60.01), 0.24–0.29 (0.27 60.05); HnL
6.10–8.75 (7.42 60.78), 7.55–9.04 (8.62 60.58); HnL/SVL
0.29–0.35 (0.32 60.02), 0.31–0.38 (0.34 60.02); HnL/FaL
1.15–1.40 (1.25 60.07), 1.16–1.39 (1.27 60.05); ThL 9.19–
12.41 (11.13 60.87), 11.38–14.34 (12.69 60.85); ThL/SVL
0.41–0.54 (0.48 60.03), 0.45–0.55 (0.50 60.03); CrL
10.24–13.24 (11.66 60.78), 12.13–15.01 (13.38 60.79);
CrL/SVL 0.42–0.56 (0.51 60.03), 0.48–0.57 (0.53 60.03);
CrL/ThL 1.00–1.13 (1.05 60.04), 1.00–1.12 (1.06 60.03);
TarL 5.55–7.6 (6.54 60.52), 6.75–8.85 (7.59 60.57); TarL/
SVL 0.25–0.31 (0.28 60.01), 0.27–0.34 (0.30 60.02); FL
9.25–12.35 (10.79 60.94), 10.66–14.45 (12.37 60.98); FL/
SVL 0.43–0.52 (0.47 60.02), 0.43–0.54 (0.49 60.02); FL/
TarL 1.52–1.76 (1.65 60.07), 1.47–1.79 (1.63 60.08).
The snout is subelliptical to pointed, or rarely mucronate
in dorsal view. The loreal region is sloped to almost vertical.
The rostrum of some specimens has a tiny vertical tubercle at
the anteriormost point, which forms a small keel. The dorsal
surface of the snout anterior to the eyes and the lips is
occasionally smooth. The palpebral membrane is usually
patterned like that of the holotype but occasionally there are
tiny black specks or brown smudges in addition to the
pigmented rim. The bifurcations of the tongue compose one-
quarter to one-sixth of the total length. The choanae are
round to slightly oblong and separated by three to four times
their greatest diameter. Supernumerary tubercles on the
fingers were not discernable in eight (15%) of the examined
specimens (MZB.Amph.26793, MZB.Amph.26855,
MZB.Amph.26859, UTA-A 63907, UTA-A 63911, UTA-A
63944, UTA-A 63945, UTA-A 63948); when present they are
on the first phalanx of finger III. The palmar surface is
variable. The palmar tubercle ranges from faint to distinct
and is often divided anteriorly. Most individuals have
rudimentary fleshy webbing between the fingers. In 13
(25%) of the individuals examined (MZB.Amph.26789,
MZB.Amph.26810, MZB.Amph.26814, MZB.Amph.26823,
MZB.Amph.26825, MZB.Amph.26888, UTA-A 63901, UTA-
A 63905, UTA-A 63906, UTA-A 63913, UTA-A 63940, UTA-
A 63947, UTA-A 63953) the webbing was more extensive.
These individuals had half or less of the proximal phalanx of
finger IV free of webbing.
A small calcar is sometimes present and the heel is
smooth or with several small round tubercles. Plantar
tubercles are numerous but often faint. There is usually an
enlarged tubercle at the base of metatarsal IV. Supernu-
merary tubercles are absent or present on the toes; when
present they are on the first phalanx of toe III, IV, or IV. The
webbing formula is I(2–2
þ
)–(2–2.5)II(1.5–2)–(3–
3.25)III(1.75–2.25)–(3–3.5)IV(3–3.25)–(2)V.
The dorsum of the trunk and limbs is tuberculate, though
the extent and size of the tubercles vary. Ventral skin is
granular to areolate on the throat, pectoral region, and
abdomen. The ventral surface of the thighs is granular to
smooth. The m. cutaneous pectoris was present in 4 (MZB.
Amph.26761, MZB.Amph.26888, UTA-A 63915, UTA-A
63931) of the 10 specimens examined for this character.
When present, it was reduced to a very thin bundle of
muscle fibers.
This species is incredibly variable in coloration and
pattern. Specimens can be nearly uniform black, to boldly
patterned with stripes and blotches of green, white, and
brown. Most specimens are a shade of brown, gray, or green,
with darker markings on the dorsum of the trunk and limbs.
Ventrally specimens are occasionally uniform black or
yellow/orange, though grayish white is the predominant
color. There are small dark flecks on the venter of most
specimens. In some cases, the flecks are dense enough to
form a reticulum. On the majority of specimens, there is a
cluster of dark pigmentation on the ventral side of each
tibiofibula–femur articulation. In almost every specimen,
there is a thin light vertical stripe on the rostrum. In several
specimens, a broad lighter stripe covers the eyelids and
dorsal surface of the head and extends posteriorly the vent. A
small number of specimens possess a thin stipe mid-dorsally
and on the dorsal surface of the thigh and crus. Darkly
colored individuals often have light eyelids and snout. Some
specimens have a single large light round spot on the flanks;
this is the only species we know of with this pattern. The iris
in most individuals is light gold to copper; the anterior and
posterior quarters have a dark brown wedge that extends
from the pupil to the margin of the eye.
Vocalization.—The call of this species is a single short
high-pitched note given every 5 to 7 s. Each note is 0.048–
0.052 s in length with a dominant frequency of 2497.85–
3014.64 Hz and a fundamental frequency of 1248.92–
1507.32 Hz. There are slight oscillations in the relative
amplitude of each note but no distinct pulses. The call is
frequency modulated with a well-defined harmonic at 4
times the fundamental frequency and weak harmonics at 6,
8, 10, and 13 times the fundamental frequency. An unedited
recording of the call is available to listen to or download at
the Cornell Lab of Ornithology Macaulay Library (available
at http://macaulaylibrary.org/) under catalog number 219805.
Etymology.—The name polymorphus is a masculine
adjective derived from the Greek words poly, meaning
many, and morph, meaning shape or form. The name refers
to the high levels of phenotypic variation displayed in this
species.
Distribution and habitat.—This species occurs in the
mountainous regions of southern and central Sumatra as far
north as Gunung Marapi, Sumatera Barat Province. We have
spent considerable time on the Toba Massif and the
mountains surrounding Panyabungan to the north without
detecting this species. Where this species occurs, it inhabits
forest at elevations between 1337 and 2204 m asl. We have
found it sympatrically with P. amabilis,P. cornutus,P.
larutensis,P. thamyridion, and P. ventrimaculatus. Both P.
polymorphus and P. refugii occur on Bukit Kaba, Bengkulu
Province, but (in our experience) P. refugii is found at
slightly lower elevations.
98 Herpetological Monographs 31, 2017
Philautus thamyridion sp. nov.
Figs. 12, 14–19
Holotype.—MZB.Amph.26763. An adult male from
Gunung Pesawaran, Kabupaten Pesawaran, Lampung Prov-
ince, Sumatra 05.515638S, 105.076678E, 1055 m asl.
Collected on 22 December 2013 by EW, Irvan Sidik, and
Ahmed Muamar Kadafi.
Paratype.—An adult female, UTA-A 63987, collected
with the holotype.
Referred specimens (37).—In addition to the type
specimens we examined 19 adult males and 18 adult females
as follows. Bengkulu: Bukit Kaba, three females (MZB.
Amph.26805 and MZB.Amph.26806, 3.494528S,
102.634248E, elev. 1443 m; UTA-A 63971, 03.500238S,
102.633668E, elev. 1574 m); Gunung Daun, eight females
(MZB.Amph.26841, UTA-A 63973, MZB.Amph.26844,
MZB.Amph.26845, and MZB.Amph.26847, 3.364498S,
102.386098E, elev. 1687 m; UTA-A 63976 and
MZB.Amph.26851, 3.36398S, 102.384258E, elev. 1724 m;
MZB.Amph.26856, 3.357628S, 102.384928E, elev. 1578 m)
and six males (MZB.Amph.26840, UTA-A 63972,
MZB.Amph.26842, MZB.Amph.26843, and UTA-A 63974,
3.364498S, 102.386098E, elev. 1687 m; MZB.Amph.26849,
3.36398S, 102.384258E, elev. 1724 m); Gunung Kambing,
one female (UTA-A 63980, 3.393688S, 102.638038E, elev.
1699 m). Lampung: vicinity of Ngarip, one female (UTA-A
63981, 5.280018S, 104.557468E, elev. 1438 m) and three
males (UTA-A 63983, and UTA-A 63984, 5.279538S,
104.557458E, elev. 1438 m); vicinity of Ranau Danau, two
males (UTA-A 63985, 4.941698S, 103.853578E, elev. 1337 m;
UTA-A 63986, 4.90548S, 103.853188E, elev. 911 m).
Sumatera Selatan: Gunung Dempo, two females (MZB.
Amph.26799, 4.042488S, 103.148528E, elev. 1760 m;
MZB.Amph.26829, 4.040658S, 103.147928E, elev. 1813 m)
and one male (MZB.Amph.26828, 4.042278S, 103.168768E,
elev. 1370 m); Gunung Patah, one female (UTA-A 64001,
04.219288S, 103.424168E, elev. 1867 m) and two males UTA-
A 63999, 4.219418S, 103.470738E, elev. 1606 m; UTA-A
64000, 4.219898S, 103.471258E, elev. 1634 m;
MZB.Amph.26796, 04.219288S, 103.4241668E, elev. 1867
m); Gunung Pesagi, four females (UTA-A 63988, 4.901928S,
104.133068E, elev. 1483 m; UTA-A 63994, 4.904128S,
104.131988E, elev. 1512 m; UTA-A 63996, 4.905898S,
104.132328E, elev. 1558 m; UTA-A 63997, 4.906948S,
104.134918E, elev. 1647 m) and three males (UTA-A
63989, 4.901928S, 104.133068E,elev.1483m;UTA-A
63990, 4.901928S, 104.133068E,elev.1483m;UTA-A
63998, 4.907468S, 104.135358E, elev. 1692 m).
Diagnosis.—This is a small (males ¼15.3–18.2 SVL n¼
20; females ¼17.2–22.2, n¼19) brown tuberculate species
with relatively long legs (CrL/SVL ¼0.58–0.71, n¼39) and
pronounced tubercles on the eyelids and dorsal surface of
the trunk, thigh, crus, and tarsus. There are more than 3.5
phalanges free of webbing on the preaxial side of toe III.
Males lack a nuptial pad. The inferior surface of the tarsus
and the plantar surface are black and there is a distinct black
spot surrounding the vent. The thighs and crus have narrow
dark bands that are widely spaced. Within each of these
bands there are enlarged tubercles.
Comparison with Sumatran Philautus.—This species is
most similar in appearance to P. cornutus and P. refugii.Itis
smaller (females ¼17.2–22.2, n¼19) than P. cornutus
(females ¼24.0–25.8, n¼5). The webbing, with 3–3.5
phalanges free of webbing on the preaxial side of toe III, is
slightly less extensive than in P. cornutus, which has 3.5–3.75
phalanges free of webbing. The canthus is angular to
rounded, sharply angular in P. cornutus. There is usually a
pair of rounded tubercles in the interorbital region that are
absent in P. cornutus. There are 1.75–2 phalanges free of
webbing on the preaxial side of toe II. In P. refugii there are
1.25–1.5 phalanges free of webbing. It is further distin-
guished from P. refugii by the lack of a bold pattern on the
preaxial surface of the thigh and the lack of a nuptial pad in
adult males. Vomerine teeth are absent, but present in P.
kerangae. There are 3.5 or more phalanges free of webbing
on the preaxial side of toe IV. Philautus amabilis and P.
larutensis have 3.25 or fewer phalanges free of webbing.
Adults are smaller (males ¼15.3–18.2 SVL, n¼20) than P.
amabilis (males ¼19.6–25.8 SVL, n¼20), P. larutensis
(males ¼20.2–25.4 SVL, n¼26), and P. polymorphus
(males19.5–27.0, n¼27) and the crus is relatively longer
(CrL/SVL ¼0.58–0.71, n¼39) than in P. amabilis (CrL/
SVL ¼0.46–0.57, n¼21), P. larutensis (CrL/SVL ¼0.49–
0.61, n ¼37), P. polymorphus (Crl/SVL ¼0.42–0.57, n¼
53), and P. ventrimaculatus (CrL/SVL ¼0.51–0.62, n¼30).
The distinctive ventral pattern of P. ventrimaculatus
separates the two species. Males lack a nuptial pad. A
nuptial pad is present in male P. larutensis.
Comparison with other Sunda Shelf Philautus.—This
species lacks vomerine teeth. Vomerine teeth are present in
P. bunitus,P. hosii,P. ingeri, and P. macroscelis. There are
3.5 or more phalanges free of webbing on the preaxial side of
toe IV. Philautus acutus,P. amoenus,P. aurantium,P.
aurifasciatus,P. davidlabangi,P. jacobsoni, P. mjobergi,P.
nephophilus,P. petersi, and P. saueri have 3.25 phalanges or
fewer free of webbing. The m. cutaneous pectoris is present.
This muscle is absent in P. acutus,P. aurantium,P.
disgregus,P. erythrophthalmus,P. tectus, and P. vermic-
ulatus. Adult males lack a nuptial pad, which is present in
male P. amoenus,P. juliandringi,P. kakipanjang,P.
mjobergi,P. nephophilus, and P. tectus. This species is
much smaller (males ¼15.3–18.2 SVL, n¼20) than P.
petersi (males ¼29.1–34.4 SVL, n¼5) and P. umbra (males
¼24.0–35.1 SVL, n¼14; Dring1987) and has prominent
tubercles on the eyelids. Philautus petersi and P. umbra lack
tubercles on the eyelid.
Description of holotype.—SVL 17.88; HL 6.75; HW
6.77; IND 2.10; EN 1.34; SnL 2.52; IOD 2.10; FaL 4.50;
HnL 4.23; ThL 9.17; CrL 10.59; TarL 5.75; FL 7.35.
HL 38% of SVL; head as wide as long (HW/HL ¼1.00);
IOD greater than EN (IOD/EN ¼1.54) and slightly smaller
than IND (IOD/IND ¼0.97); snout weakly pointed in dorsal
view and slightly acute and protruding in profile; canthus
rostralis angular and slightly concave; loreal region vertical;
lips angled out from lores; nostril small, round, laterally
oriented; tympanum discernable, covered in skin the same
color and texture as the surrounding area, annulus present,
superior margin covered by supratympanic fold; supra-
tympanic fold low, extends from posterior margin of eye to
just above insertion of forelimb; pupil horizontal; palpebral
membrane mostly clear centrally with a thin band of brown
flecks along the rim and brown flecks and smudges
peripherally; lingual papilla absent; vomerine teeth absent;
99
WOSTL ET AL.—SUMATRAN PHILAUTUS
FIG. 12.—Philautus thamyridion. MZB.Amph.26763, holotype, male 17.88 mm, Gunung Pesawaran, Lampung (A and B). UTA-A 63987, paratype,
female, 19.82 mm snout–vent length (SVL), Gunung Pesawaran, Lampung (C). UTA-A 63976, female, 19.91 mm SVL, Gunung Daun, Bengkulu (D).
MZB.Amph.26796, male, 17.37 mm SVL Gunung Patah, Sumatera Selatan (E). UTA-A 63982, male, 15.42 mm SVL, vicinity of Ngarip, Lampung, showing
black spot surrounding vent and black coloration on inferior surface of tarsus (F). A color version of this figure is available online.
100 Herpetological Monographs 31, 2017
choanae tiny, round, and widely spaced, straight line
distance between choanae about 7.8 times greatest diameter;
tongue bifurcate posteriorly, approximately two-thirds free.
Forearm 25% of SVL; hand 24% of SVL, 96% of
antecubital; nuptial pad absent; palmar tubercle round,
flattened, and indistinct; thenar tubercle indistinct; distinct
tubercle at distal end of metacarpals III and IV, just proximal
to metacarpal/phalangeal articulation; subarticular tubercles
round, basal of finger III absent, basal of finger IV faint;
supernumerary tubercle on first phalanx of finger III; finger
pads entire, slightly broadened; ungual flap present on all
fingers; dermal fringe on fingers not discernable; webbing
between fingers fleshy and barely discernable; relative finger
length I ,II ,IV ,III.
Thigh 51% of SVL; crus 59% of SVL, 111% of ThL; tarsus
32% of SVL; foot 41% of SVL and 128% of TarL; plantar
surface with numerous tiny tubercles; small distinct tubercle
at base of fourth metatarsal; inner metatarsal tubercle oblong
and flat; subarticular tubercles round and flat; supernumer-
ary tubercles absent; toe pads entire, slightly broadened, a
little smaller than finger pads; ungual flap present on all toes;
dermal fringe to disc on toes II–V; relative toe length I ,II
,III ¼V,IV; webbing formula I2–2.5II2
þ
–3.25III2.5–
3.75IV3.25–2V.
Dorsal surface of snout anterior to eyes and lips with
numerous distinct tubercles; tubercle at tip of snout, very
small; eyelid with large distinct conical tubercles; interocular
region with a pair of enlarged rounded tubercles; mandible
with row of small conical tubercles on posterior half;
enlarged tubercles in the postorbital, supratympanic, and
suprascapular regions. Tubercles in the postorbital and
suprascapular regions converge posteriorly; dorsal surface of
antecubital, trunk, thigh, and crus with distinct tubercles;
enlarged tubercles on the thigh and crus located within the
narrow dark bands on the leg; distinct tubercles in loose row
on postaxial margin of crus; postaxial margin of tarsus and
foot with row of tubercles; calcar present, small; ventral skin
granular to areolate, weakly areolate on throat; m. cutaneous
pectoris present; pectoral septum attached broadly across
pectoral region.
The coloration of the holotype is brown overall, slightly
lighter on the sides, with dark brown bands on hand,
antecubital, thigh, crus, tarsus, and foot. The bands on the
thigh and crus are narrow and widely spaced. Tympanic
regions the same color as the bands on the limbs Illdefined
dark bars on the lips. On the dorsum, there is a dark forward
pointing V originating lateral to the sacral humps and
terminating mid-dorsally posterior to the scapula. Interor-
bital region with dark mottling. Ventrally the pectoral region
and abdomen are white. The throat and a small patch on the
posterior venter are dull yellow. The throat and pectoral
region are mottled with dusky flecks. The inferior surface of
the tarsus and foot is black and there is a distinct black spot
surrounding the vent. The iris is bronze with a darker patch
anterior and posterior to the pupil.
Variation.—On the basis of 20 adult males and 19 adult
females from Sumatra. SVL 12.28–18.19 (17.05 60.85),
17.19–22.2 (20.01 61.17); HL 6.37–7.46 (6.85 60.33),
7.25–8.61 (8.05 60.39); HL/SVL 0.38–0.43 (0.40 60.01),
0.38–0.42 (0.40 60.01); HW 5.99–6.94 (6.56 60.27), 6.61–
7.95 (7.44 60.32); HW/HL 0.90–1.03 (0.95 60.01), 0.85–
1.00 (0.93 60.04); IND 1.85–2.18 (2.01 60.08), 2.10–2.65
(2.36 60.15); IND/HL 0.28–0.31 (0.29 60.01), 0.27–0.32
(0.29 60.01); EN 0.95–1.43 (1.24 60.12), 1.29–1.67 (1.47
60.10); EN/HL 0.15–0.20 (0.18 60.01), 0.17–0.20 (0.18
60.01); SnL 2.05–2.82 (2.56 60.16), 2.65–3.33 (3.01,
0.18); SnL/HL 0.31–0.41 (0.37 60.02), 0.35–0.39 (0.37 6
0.01); IOD 1.89–2.25 (2.06 60.11), 1.95–2.49 (2.25–0.14);
IOD/EN 1.42–2.00 (1.67 60.15), 1.35–1.81 (1.53 60.12);
IOD/IND 0.95–1.13 (1.02 60.04), 0.87–1.10 (0.95 60.07);
FaL 4.03–4.66 (4.35 60.20), 4.33–5.56 (5.06 60.29); FaL/
SVL 0.24–0.28 (0.26 60.01), 0.22–0.28 (0.25 60.01); HnL
4.23–5.46 (4.89 60.34), 5.30–6.40 (5.88 60.35); HnL/SVL
0.24–0.32 (0.29 60.02), 0.26–0.33 (0.29 60.02); HnL/FaL
0.94–1.35 (1.13 60.09), 1.06–1.25 (1.16 60.06); ThL 7.92–
10.34 (9.22–0.54), 10.37–12.95 (11.40 60.56); ThL/SVL
0.48–0.60 (0.54 60.03), 0.53–0.63 (0.57 60.02); CrL
10.11–11.39 (10.67 60.34), 11.99–13.86 (12.87 60.47);
CrL/SVL 0.58–0.71 (0.63 60.04), 0.60–0.71 (0.64 60.03);
CrL/ThL 1.05–1.3 (1.16 60.06), 1.03–0.21 (1.12 60.04);
TarL 5.6–6.75 (5.99 60.28), 6.60–7.90 (7.11 60.28); TarL/
SVL 0.32–0.39 (0.35 60.02), 0.33–0.40 (0.36, 0.02); FL
7.10–8.85 (7.90 60.43), 8.75–10.3 (9.4 60.49); FL/SVL
0.41–0.52 (0.47 60.03), 0.43–0.56 (0.47 60.03); FL/TarL
1.20–1.44 (1.32 60.06), 1.23–1.43 (1.32 60.06).
The snout of most individuals is pointed when viewed
from above, occasionally subelliptical, and acute to protrud-
ing in profile. The canthus rostralis is usually angular and
slightly concave. It is rounded in a few. The loreal region is
vertical to sloped.
The dorsal surface of snout anterior to eyes is usually
tuberculate. There is a very slight protrusion on the rostrum
of six (15%) of the examined specimens (MZB.Amph.26843,
UTA-A 63971, UTA-A 63985, UTA-A 63986, UTA-A 63997,
UTA-A 63996), the presence or absence of which does not
correspond to sex. Almost all individuals possess a pair of
enlarged rounded tubercles in the interorbital region. The
palpebral membrane is clear centrally with a thin band of
pigmentation along rim the color of the eyelid and is invaded
to various extents peripherally by small brown specks or the
surrounding coloration. The straight-line distance between
the choanae is five to eight times greater than their greatest
diameter. The tongue is bilobed and is one-third to two-
thirds free; each bifurcation makes up 11–17% of total
tongue length.
There is almost always a small supernumerary tubercle on
the proximal phalanx of finger III; it was not evident in just
one specimen (UTA-A 63989). A weakly developed dermal
fringe is usually evident on fingers II–IV, extending to the
disc.
The proximal subarticular tubercle of the fourth toe is
usually absent, though it was present in three individuals
(MZB.Amph.26763, MZB.Amph.26847, UTA-A 63976). The
proximal subarticular tubercle of toes III and V is often
reduced in size and faint. One individual (UTA-A64001) had
a small supernumerary tubercle on the first phalanx of toe
IV. Two individuals (MZB.Amph.26851 and UTA-A 63973)
had a small supernumerary tubercle on the first phalanx of
toe V located immediately distal to the metatarsal–phalan-
geal articulation. The variation in the extent of the webbing
on the foot can be summarized by the webbing formula I(2)–
(2.25–2.75)II(1.75–2)–(3.25–3.5)III(2.25–3)–(3.5–4)
IV(3.25–3.75)–(2–2.5)V. The presence or absence of a calcar