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A Cryptic New Species of Polemon (Squamata: Lamprophiidae,
Aparallactinae) from the Miombo Woodlands of Central and East Africa
Frank Portillo
1
, William R. Branch
2
, Colin R. Tilbury
3
, Zolta´n T. Nagy
4
, Daniel F.
Hughes
1
, Chifundera Kusamba
5
, Wandege M. Muninga
5
, Mwenebatu M. Aristote
6
,
Mathias Behangana
7
, and Eli Greenbaum
1
African snake-eaters of the genus Polemon are cryptic, fossorial snakes that mainly inhabit the forests of central,
eastern, and western Africa. Molecular results from a previous study demonstrated that Polemon christyi is not
monophyletic—two distinct lineages were recovered from Uganda (the type locality) and southeastern Democratic
Republic of the Congo (DRC). Genetic data indicated differences in sequence divergence and encoded amino acids
between these lineages. Based on these molecular differences and diagnostic differences in morphology, we describe
the lineage from southeastern DRC as a new species. Literature records indicate that it likely occurs in adjacent
Tanzania and Zambia. It is the first species of Polemon to be described in over 70 years.
THE 13 species of currently recognized snakes of the
genus Polemon are cryptic, fossorial inhabitants of
forests and woodland/savanna mosaic habitats
throughout central, eastern, and western Africa (Chippaux,
2006; Uetz et al., 2018). Snakes, particularly typhlopids, form
their main diet, hence the common name ‘Snake Eaters.’
Most species of the genus rarely exceed 80 cm total length,
but they can be voracious predators that consume snakes of
equal size (Pitman, 1974; Kusamba et al., 2013; Spawls et al.,
2018). Like many other lamprophiids, these fossorial and
secretive snakes are poorly known, both in terms of natural
history and taxonomy (i.e., low numbers of specimens
available in museums), but most species have grooved rear
fangs and are ophiophagous, nocturnal, and oviparous
(Spawls et al., 2018). Many species also have prominent
yellow or orange neck bands (Underwood and Kochva, 1993;
Spawls and Branch, 1995; Spawls et al., 2018).
Based on hemipenial, dentition, and osteological charac-
ters, Bogert (1940) gave the first definitive arrangement of
aparallactines, which included the genera Amblyodipsas,
Aparallactus,Brachyophis,Chilorhinophis,Elapotinus,Hypopto-
phis, Macrelaps,Micrelaps,Poecilopholis,Polemon, and Xenoca-
lamus. De Witte and Laurent (1943, 1947) revised
aparallactines into three groups, with Elapocalamus (Bou-
lenger, 1911), Chilorhinophis (Werner, 1907), Polemon (Jan,
1858), Miodon (Dum´
eril, 1859), Cynodontophis (Werner,
1902), and Melanocalamus (de Witte, 1941) comprising their
‘‘Deuxi`
eme Groupe,’’ which was characterized by the
presence of a maxillary-ectopterygoid foramen. Currently,
only two genera from the ‘‘Deuxi`
eme Group’’ are recognized,
with all genera except Chilorhinophis placed in the synonymy
of Polemon (Laurent, 1956a; Hughes and Barry, 1969; Resetar
and Marx, 1981). In a recent, major phylogenetic analysis of
aparallactines, these two fossorial genera were recovered as
sister taxa with strong support (Portillo et al., 2018: fig. 2).
Relationships within the genus Polemon have historically
been poorly understood and reliant solely on morphological
data. Only recently have relationships within the genus been
studied with molecular data (Fig. 1; e.g., Pyron et al., 2013;
Figueroa et al., 2016; Portillo et al., 2018). Because many of
the species share morphological characters that often
overlap, taxonomic classification of species of Polemon has
been challenging. Many of the 13 currently recognized
species were historically considered to be geographic variants
or synonyms of fewer species (Loveridge, 1942, 1944; de
Witte and Laurent, 1947; Pitman, 1974; Spawls et al., 2018).
For example, the poorly known species P. c h r i s t y i was
considered to be a race of either P. collaris or P. gabonensis at
different times (Loveridge, 1942, 1944, 1957; Pitman, 1974).
This is unsurprising, because the three taxa overlap consid-
erably in morphological characters, including ventral and
subcaudal scale counts (de Witte and Laurent, 1947; Pitman,
1974). However, de Witte and Laurent (1947) and Laurent
(1956a) considered P. christyi to be a distinct species based on
dorsal coloration, because it has a grayish black dorsum and
lacks a neck band, whereas P. collaris and P. gabonensis both
have a yellowish band on the neck. Polemon christyi is also
partially sympatric with another superficially similar member
of the genus, P. graueri, which can be grayish black dorsally,
but with a more slender build and a larger number of ventral
scales (de Witte and Laurent, 1947; Pitman, 1974). Currently,
P. christyi is considered to occur throughout much of the
Albertine Rift region (Spawls et al., 2018), including eastern
Democratic Republic of Congo (DRC; absent from the
western lowlands, sensu Broadley,1998),SouthSudan
(Wallach et al., 2014), and western Kenya (L¨
otters et al.,
2007), to northern Zambia (Broadley et al., 2003) and
Tanzania (Loveridge, 1944; Caro et al., 2011; Spawls et al.,
2018), with a single record from northern Malawi (Mercurio,
2007). Recent molecular results demonstrated that P. christyi
1
Department of Biological Sciences, University of Texas at El Paso, 500 W. University Ave., El Paso, Texas 79968; Email: (EG) egreenbaum2@
utep.edu. Send reprint requests to EG.
2
Port Elizabeth Museum, P.O. Box 11347, Humewood 6013, South Africa; and Department of Zoology, P.O. Box 77000, Nelson Mandela
Metropolitan University, Port Elizabeth 6031, South Africa. Deceased.
3
Department of Botany & Zoology, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa.
4
Hielscherstr 25, D-13158 Berlin, Germany.
5
Laboratoire d’Herp´
etologie, D´
epartement de Biologie, Centre de Recherche en Sciences Naturelles, Lwiro, South Kivu, Democratic Republic of
the Congo.
6
Institut Sup´
erieur d’´
Ecologie pour la Conservation de la Nature, Katana Campus, South Kivu, Democratic Republic of the Congo.
7
Department of Environmental Sciences, Makerere University, P.O. Box 7298, Kampala, Uganda.
Submitted: 25 July 2018. Accepted: 2 November 2018. Associate Editor: B. Stuart.
Ó2019 by the American Society of Ichthyologists and Herpetologists DOI: 10.1643/CH-18-098 Published online: 24 January 2019
Copeia 107, No. 1, 2019, 22–35
is not monophyletic—topotypic P. christyi is found in eastern
Africa and is sister to central African P. robustus, whereas a
second lineage occurs in southeastern DRC and is sister to the
widespread species P. collaris (Figs. 1, 2; Portillo et al., 2018).
Herein, we examine the taxonomic status of these lineages of
P. c h r i s t y i in more detail with morphological data and
additional molecular analyses.
MATERIALS AND METHODS
Molecular analyses.—To understand molecular variation
within the genus Polemon,weuseddatafromthree
mitochondrial (16S, cyt b, and ND4) and two nuclear genes
(c-mos and RAG1) that were sequenced and analyzed in a
phylogenetic context in the study of Portillo et al. (2018).
Levels of sequence divergence between haplotypes were
inferred using uncorrected p-distances calculated from MEGA
version 7.0 (Kumar et al., 2016). We also analyzed differences
in amino acid translation of the protein-coding genes ND4
and cyt bfor samples of Polemon christyi (UTEP 21618) and P.
cf. christyi (PEM R20734 and PEM R17452). No nuclear data
were available for P. christyi.
Morphological analyses.—Specimens examined for this study
(Material Examined) were collected from multiple localities
throughout sub-Saharan Africa, and are housed in the
collections of the Port Elizabeth Museum, the University of
Texas at El Paso Biodiversity Collections, and the Royal
Belgian Institute of Natural Sciences. Additional aparallactine
specimens, including relevant type specimens, were cited or
examined from a diversity of collections and institutions as
listed in the Material Examined.
Specimens were examined under a Zeiss Stemi 2000-C
stereo microscope, and photographs were taken with a
Canon Rebel T3i DSLR camera and Canon 6D full frame
DSLR camera. Characters were chosen from previous taxo-
nomic studies of advanced snakes (LaDuc and Johnson,
2003; Devitt et al., 2008; Moyer and Jackson, 2011; Anderson
and Greenbaum, 2012; Greenbaum et al., 2015). Snout–vent
length (SVL) was measured with a metric ruler and rounded
to the nearest 1.0 mm. All other measurements were taken
from the right side of the body with digital calipers under a
dissecting microscope and rounded to the nearest 0.1 mm.
Morphological data consisted of 18 mensural and 14
meristic characters. Mensural data included: snout–vent
length (SVL); tail length (TL); head width (HW)—measured
at widest point of head; head length (HL)—measured at angle
of jaw, from posterior edge of mandible to tip of snout; naso-
Fig. 1. Phylogenetic tree depicting relationships of African Polemon, based on Portillo et al. (2018). Branch support values are Bayesian inference
posterior probabilities/maximum likelihood bootstrap support values. See Data Accessibility for tree file.
Fig. 2. Map of Central Africa showing sampling localities for Polemon
christyi and P. ater. Star represents the type locality for the new species.
Portillo et al.—New species of Polemon 23
ocular distance (NOD; taken at the anterior border of the eye
to posterior border of nare); eye to snout length (ES; taken at
the anterior border of the eye); interocular distance (ID); eye
diameter (EW; anterior–posterior); internasal scale width
(INAS); rostral scale height (RH); rostral scale width (RW);
frontal scale length (FL); frontal scale width (FW); chin shield
length (CSL); chin shield width (CSW); prefrontal scale
length (PFL); prefrontal scale width (PFW); and mouth gape
(MG). Meristic data included: number of ventral scales
(VENT)—following the standard and Dowling methods
(Dowling, 1951); subcaudals (SCDL); dorsal scale rows at
the neck (DSRN; one head length posterior to jaw rictus);
dorsal scale rows at midbody (DSRM); dorsal scale rows one
head length anterior to the cloaca (DSRC); prefrontals (PFRO;
size and number); internasals (INAS; size and number);
number of supralabials (SUPRA); number of supralabials in
contact with the eye (SUIE); number of infralabials (INFRA);
number of supralabials in contact with chin shields (LLC);
preoculars (PRE); postoculars (PO); and temporal arrange-
ment (T).
Mean, standard deviation, and range of mensural and
meristic characters were calculated for each group indicated
by the phylogeny. To eliminate the effect of size, analyses of
covariance (ANCOVA) were conducted with snout–vent
length as the covariate (Packard and Boardman, 1999).
Principal components analyses (PCA) of mensural data were
conducted in Minitab 15 (Minitab Statistical Software, State
College, PA) and used to identify patterns of variation in the
data. All analyses used the covariance matrix. PCA analyses
were conducted using log-transformed mensural data (mea-
surements pertaining to the head). Residual data obtained
from the ANCOVA analyses were used for PCA analyses.
RESULTS
Molecular analyses.—Cytochrome bdistances ranging from
2.5% to 5.3% were observed between Polemon cf. christyi
(hereafter referred to as P. ater, new species) and its sister
taxon P. collaris, and a genetic divergence of 14.0% was
recovered between P. a t e r , new species, and P. c h r i s t y i
(Supplementary Table 1; see Data Accessibility). Genetic
distances of ND4 ranged from 2.4% to 3.6% between P. ater,
new species, and P. collaris, and a genetic divergence of 14.1%
was recovered between P. ater, new species, and P. christyi
(Supplementary Table 1; see Data Accessibility). Divergences
recovered from the 16S gene and nuclear DNA data sets were
noticeably lower; uncorrected p-distances calculated from
16S, c-mos, and RAG1 ranged between 0% to 0.8% (P. ater,
new species, and P. collaris) and 0.4% (P. ater, new species, and
P. christyi; Supplementary Table 1; see Data Accessibility).
Cytochrome band ND4 divergences between P. ater, new
species, and other species of Polemon are shown in Supple-
mentary Table 1 (see Data Accessibility).
Twenty-five major differences in amino acid translation
were noted in ND4 and cyt bdata from lineages of Polemon
from DRC and Uganda. For ND4, amino acid codon positions
43, 47, 116, 130, 134, 164, 169, 189, 211, 213, 217, and 223
translated to threonine, alanine, isoleucine, threonine,
leucine, threonine, leucine, methionine, methionine, methi-
onine, methionine, and proline for P. ater, new species,
whereas the same positions translated to alanine, serine,
threonine, alanine, isoleucine, valine, phenylalanine, threo-
nine, leucine, threonine, alanine, and serine in P. christyi. For
cyt b, amino acid codon positions 57, 58, 63, 69, 76, 108,
113, 149, 151, 153, 162, 171, 175, 180, and 185 translated to
methionine, threonine, cysteine, isoleucine, threonine,
threonine, isoleucine, threonine, leucine, valine, asparagine,
alanine, isoleucine, threonine, and leucine for P. ater, new
species, whereas the same positions translated to isoleucine,
methionine, tyrosine, threonine, isoleucine, valine, threo-
nine, alanine, isoleucine, isoleucine, aspartic acid, threonine,
leucine, isoleucine, and serine in P. christyi.
Morphological analyses.—Morphometric data for examined
specimens of Polemon (P. christyi,P. ater, new species, and P.
collaris) are presented in Tables 1 and 2. The principal
components analysis (PCA) with head morphometric data
regressed against SVL is shown in Figure 3 and Table 1. The
first two PC axes accounted for most of the variation in the
data (87.5%; Fig. 3, Table 1). The first PC axis was an
indicator of general head size relative to body size; specimens
towards the right of the graph were considered to have larger
heads relative to body length. The second PC axis loaded
negatively for head length; negative values on this axis were
correlated with shorter heads relative to body length (Fig. 3).
The PC analysis showed a clear separation between P. ater,
new species, and samples of P. collaris, but there was some
overlap between P. ater, new species, and samples of P. christyi
(Fig. 3).
We found a large amount of overlap in morphological
characters (size and scalation) between several taxa of
Polemon (P. christyi [n¼5], P. ater, new species, [n¼2], P.
collaris [n¼8], and P. gabonensis [n¼8]; Table 2; Chippaux,
2006; Chirio and LeBreton, 2007; Pauwels and Vande weghe,
2008). This is common within the genus because species are
morphologically conserved. The easiest way to distinguish
these lineages of Polemon is by a combination of characters
including shape of the postocular, shape of the nasal scales,
dorsal coloration, ventral coloration, and presence/absence
of an orange or yellow neck band.
Conclusion.—The two populations, P. christyi and P. ater, new
species, are distinguished by subtle differences in morphol-
ogy and substantial mitochondrial molecular differences.
Moreover, P. ater, new species, is known only from grassland/
miombo woodland, whereas P. christyi occurs mostly in
forest, although it enters grassland and woodland in
northeastern DRC (de Witte, 1966; Pitman, 1974). We
consider these differences to indicate that these lineages are
specifically distinct, and therefore describe the population
from southeastern DRC as a new species.
Polemon ater, new species
Black Snake-eater
urn:lsid:zoobank.org:act:6256E503-4C74-4033-BABE-CEE8
C42A067E
Figures 4, 5, 6; Table 2
Miodon gabonensis christyi, Loveridge (1944; part): 170, 178–
180.
Miodon christyi, Laurent (1947; part): 10.
Miodon christyi, de Witte and Laurent (1947; part): 8, 60, 73–
75, figs. 67–69.
Miodon christyi, de Witte (1953): 264–265, fig. 91.
Miodon christyi, Laurent (1955; part): 293.
Miodon christyi, Laurent (1956b): 252.
Miodon collaris christyi, Loveridge (1957; part): 283.
Miodon christyi, Broadley and Pitman (1960): 437, 447.
Miodon christyi, Bourgeois (1968: part): 179, 284.
Polemon christyi, Broadley (1971): 26, 76.
24 Copeia 107, No. 1, 2019
Miodon christyi, Pitman (1974: part): 135, 165–168, 205,
colour plate M, fig. 3, plate XII.
Polemon christyi, Welch (1982; part): 142.
Polemon christyi, Hughes (1983; part): 316, appendix A.
Polemon christyi, Chifundera (1990; part): table 1.
Polemon christyi, Broadley and Howell (1991; part): 29, 35, 62.
Polemon christyi, Broadley (1998; part): xxx.
Polemon christyi, Behangana and Goodman (2002; part): 64.
Polemon christyi, Spawls et al. (2002; part): 426.
Polemon christyi, Broadley et al. (2003): 95–96, fig. 17.
Polemon christyi, Broadley and Cotterill (2004; part): 47, 52.
Polemon christyi, Spawls et al. (2004; part): 426.
Polemon christyi, Chirio and Ineich (2006; part): 58.
Polemon christyi,L
¨
otters et al. (2007; part): 98–99, plate 12.
Polemon christyi, Caro et al. (2011; part): 561.
Polemon christyi, Wallach et al. (2014; part): 561, table 1.
Polemon christyi, Tilbury and Branch (2014): 36–38, figs. 1
(two figures labeled fig. 1).
Polemon christyi, Spawls et al. (2018; part): 461, unnumbered
figure.
Holotype.—PEM R20734, subadult male, Democratic Republic
of the Congo, Lualaba Province, Fungurume, 10.53388S,
26.33758E, 1189 m, C. Tilbury, 12 February 2014 (Tilbury and
Branch, 2014).
Paratype.—PEM R17452, adult female, Democratic Republic
of the Congo, Lualaba Province, Kalakundi, 10.65508S,
25.93258E, 1472 m, W. R. Branch, 25 January 2008.
Referred material.—Given the morphological similarities
(scale counts and coloration) between southern populations
previously referred to P. christyi, we provisionally assign
records from southeastern DRC (de Witte and Laurent, 1943,
1947; de Witte, 1953; Laurent, 1956b), Zambia (Broadley,
1971; Broadley et al., 2003), and west-central Tanzania
Table 1. Principal components analysis (PCA) comparing Polemon
ater, new species, with P. christyi and P. collaris, with natural log-
transformed morphometric data regressed against SVL. Eigenvalues,
percent variance, cumulative variance, and loadings are shown for the
first three principal components. See Materials and Methods for
abbreviations.
Variable PC1 PC2 PC3
RESI 1 (SVL/HL) 0.738 –0.617 0.207
RESI 2 (SVL/HW) 0.41 0.244 –0.605
RESI 3 (SVL/NOD) 0.019 –0.028 –0.113
RESI 4 (SVL/ES) 0.083 0.104 –0.368
RESI 5 (SVL/ID) 0.129 0.007 –0.061
RESI 6 (SVL/EW) 0.033 0.024 –0.006
RESI 7 (SVL/INAS) 0.146 –0.084 –0.331
RESI 8 (SVL/RH) 0.06 0.061 –0.067
RESI 9 (SVL/RL) 0.089 0.123 –0.146
RESI 10 (SVL/FL) 0.093 0.144 –0.106
RESI 11 (SVL/FW) 0.008 0.033 –0.068
RESI 12 (SVL/CSL) 0.064 0.133 –0.078
RESI 13 (SVL/CSW) 0.036 0.006 –0.072
RESI 14 (SVL/PFL) 0.048 0.002 –0.094
RESI 15 (SVL/PFW) 0.019 0.047 –0.158
RESI 16 (SVL/MG) 0.462 0.693 0.493
Eigenvalue 6.9697 1.1179 0.5637
Proportion 0.754 0.121 0.061
Cumulative 0.754 0.875 0.936
Table 2. Morphometric data (in mm) and meristic scale counts for examined specimens of Polemon christyi,P. collaris, and P. ater, new species. For character abbreviations, see Materials and Methods.
Data are shown as mean6standard deviation with range in parentheses. Asterisks next to species names indicates data included from type specimens.
Character
*Polemon ater,
new species, female
(n¼1) paratype
*Polemon ater,
new species, male
(n¼1) holotype
Polemon christyi
females (n¼2)
*Polemon christyi
males (n¼3)
*Polemon collaris
females (n¼4)
*Polemon collaris
males (n¼4)
SVL 640 254 758.5620.5 (744–773) 430.06213.0 (231–654) 502.36116.0 (364–642) 372.96163.8 (230–608)
TL 27.9 17.0 38.163.46 (35.6–40.5) 30.2616.6 (15.7–48.4) 24.361.5 (22.3–25.8) 28.2610.0 (14.7–38.5)
HL 13.6 7.9 22.965.2 (19.2–26.6) 13.165.7 (8.8–19.5) 14.062.0 (11.5–16.4) 11.564.1 (9.1–17.6)
HW 10.2 4.5 14.461.9 (13.0–15.7) 8.864.8 (4.7–14.1) 8.360.8 (7.1–8.9) 7.362.4 (5.4–10.9)
VENT — 211 229.560.7 (229–230) 205.765.9 (199–210) 239.369.5 (231–251) 206.8618.0 (180–219)
SCDL 15 20 17.562.1 (16–19) 20 17.561.3 (16–19) 23.361.7 (21–25)
DSRM 15 15 15 15 15 15
SUPRA 7 7 7 7 7 7
INFRA 7 7 7 7 7 7
PREOC 1 1 1 1 1 1
POSTOC 2 2 2 2 2 2
Portillo et al.—New species of Polemon 25
(Loveridge, 1944; Caro et al., 2011; Spawls et al., 2018) to P.
ater.
Diagnosis.—Polemon ater is a medium to large aparallactine.
The dorsum and venter are uniformly grayish black or black,
with ventrals and subcaudals each edged posteriorly in silver
white, lacking any lighter tones or shades anywhere on the
dorsum and lacking a distinct collar; the preocular scale is
irregular in shape (somewhat triangular with a rounded top);
dorsally the head narrows towards the snout. Cytochrome b
and ND4 pairwise sequence divergence rates between P. ater
and its closest relative (P. collaris) ranged between 2.5% to
5.3%.
Comparisons.—(Figs. 4, 5, 6; Table 2) Based on examined
material and published details (Boulenger, 1903; de Witte,
1941, 1953, 1962, 1966; de Witte and Laurent, 1943, 1947;
Laurent, 1956a, 1956b, 1960; Pitman, 1974; Broadley and
Howell, 1991; Meirte, 1992; Broadley et al., 2003; Chip-
paux, 2006; Trape and Man´
e, 2006; Chirio and LeBreton,
2007; Pauwels and Vande weghe, 2008), P. a t e r differs from
P. ac a n t h i a s by dorsal coloration (grayish black or black vs.
whitish or pale reddish with five black stripes in P.
acanthias), having a divided cloacal plate (entire in P.
acanthias), and ventral coloration (grayish black or black
with silver-white edging on ventral and subcaudal scales vs.
white in P. acanthias); from P. b a r t h i i by the number of
postocular scales (two vs. one in P. b a r t h i i ), the shape of the
preocular scale (irregular vs. trapezoidal in P. b a r t h i i ), dorsal
coloration (grayish black or black vs. olive in P. b a r t h i i ),
having a divided cloacal plate (entire in P. b a r t h i i ), and
ventral coloration (grayish black or black with silver-white
edging on ventral and subcaudal scales vs. yellowish white
in P. barthii); from P. b o c o u r t i by the shape of the preocular
scale (irregular vs. triangular in P. b o c o u r t i ), and lacking a
distinct collar (distinct creamy yellow collar in P. b o c o u r t i ),
having a divided cloacal plate (entire in P. b o c o u r t i ), and
having a narrower snout; from P. fulvicollis by the number
of ventral scales (202–242 vs. 247–267 in P. fulvicollis), body
shape (stout vs. slender and long in P. fulvicollis), ventral
coloration (grayish black or black with silver-white edging
on ventral and subcaudal scales vs. white in P. fulvicollis),
and lacking a distinct collar (yellowish or orange collar
present in P. fulvicollis); from P. gracilis by the number of
infralabials (seven vs. six in P. gracilis), the number of
ventral scales (202–242 vs. 246–284 in P. gracilis), ventral
coloration (grayish black or black with silver-white edging
on ventral and subcaudal scales vs. white or cream in P.
gracilis), and absence of a collar (yellowish collar present in
P. gracilis); from P. g r a u e r i by the number of ventral scales
(202–242 vs. 222–262 in P. g r a u e r i ), ventral coloration
(grayish black or black with silver-white edging on ventral
and subcaudal scales vs. cream or white in P. g r a u e r i ), and
shape of the preocular (irregular vs. triangular in P. g r a u e r i );
from P. g r i s e i c e p s by the number of ventral scales (202–242
vs. 177–200 in P. g r i s e i c e ps )andventralcoloration(grayish
black or black with silver-white edging on ventral and
subcaudal scales vs. cream or white in P. griseiceps); from P.
neuwiedi by dorsal coloration and pattern (grayish black or
black vs. pale brown with three black stripes in P. n e u w i e d i )
and ventral coloration (grayish black or black with silver-
white edging on ventral and subcaudal scales vs. white in P.
neuwiedi); from P. notatus by dorsal coloration (grayish black
or black vs. pale brown with two series of round black spots
in P. n o t a t u s ), number of ventral scales (202–242 vs. 181–
200 in P. notatus), ventral coloration (grayish black or black
with silver-white edging on ventral and subcaudal scales vs.
white in P. n o t a t u s ), and number of postocular scales (two
vs. one or two in P. notatus); from P. r o b u s t u s by the shape of
the preocular scale (irregular vs. rectangular and long
vertically in P. r o b u s t u s ), lack of a distinct collar (yellowish
orange collar present in P. r o b u s t u s ), shape of the snout
laterally (narrow vs. wide in P. r o b u st u s ), and number of
ventral scales (202–242 vs. 163–189 in P. r o b u s t u s ); from P.
christyi, to which it is morphologically most similar, by the
shape of the postocular scales (upper postocular scale is
noticeably larger than the lower postocular scale vs. equal-
sized postocular scales in P. c h r i s t y i )andshapeofthenasal
scales (square-like vs. irregular shaped in P. c h r i s t y i ); from P.
collaris by lacking a distinct collar (tan or yellow collar
present in P. collaris), the shape of the postocular scales (top
postocular scale is noticeably larger than the bottom
postocular scale vs. equal-sized postocular scales in P.
collaris), shape of the nasal scales (square-like vs. irregular
Fig. 3. Scatter plots of PC1 and PC2
scores for the analysis with morpho-
metric data regressed against SVL for
examined specimens of Polemon.
26 Copeia 107, No. 1, 2019
shaped in P. collaris), ventral coloration (grayish black or
black with silver-white edging on ventral and subcaudal
scales vs. white or cream in P. collaris), and a narrower head;
and also from P. g a b o n e n s i s by the shape of its preocular
scale (irregular vs. elongated and triangular in P. g a b o n e n -
sis), shape of the postocular scales (top postocular scale is
noticeably larger than the bottom postocular scale vs.
equal-sized postocular scales in P. gabonensis), shape of the
nasal scales (square-like vs. irregular shaped in P. g a b o n e n -
sis), a less robust snout, lack of a distinct collar (yellowish
light gray collar present in P. gabonensis), and ventral
coloration (grayish black or black with silver-white edging
on ventral and subcaudal scales vs. creamy yellow lower
labials and venter in P. gabonensis).
Description of the holotype.—(Figs. 4, 5, 6; Table 2) Subadult
male 254 mm SVL; interocular distance 3.1 mm, pupil round,
eye diameter 0.9 mm; no loreal; body cylindrical; tail short
(17.0 mm, 6.69% of SVL); body stout; head slightly distinct
from neck; dorsally, head slightly wider than neck and
progressively narrower towards tip of snout; laterally, head
narrow, widest point at back of head and narrower at nostrils;
nostrils visible from above; scales smooth and glossy. Supra-
labials 7 (left)/7 (right), 3
rd
–4
th
/3
rd
–4
th
contacting orbit;
infralabials 7/7, 1
st
on each side in contact behind mental,
1
st
–4
th
/1
st
–4
th
contacting anterior chin shields; 1/1 preocular;
2/2 postoculars; temporals 1þ1/1þ1; two internasals; nasal
divided; frontal is longer (2.5 mm) than wide (1.6 mm);
dorsal scales 15 one head length posterior to jaw rictus, 15 at
midbody, and 15 one head length anterior to cloaca; ventrals
211 (Dowling count: 208); cloacal plate divided; all paired
subcaudals 20. Maxillary dentition—two small anterior teeth,
followed by a very large, deeply grooved fang positioned
anterior to eye, followed posteriorly by 12 smaller teeth on
each side. These data are nearly identical to those reported by
Tilbury and Branch (2014).
Coloration of the holotype in life.—(Fig. 4) Dorsum and venter
uniform glossy grayish black, with ventrals and subcaudals
each edged posteriorly in silver white (Tilbury and Branch,
2014). The anterior forked portion of the tongue is silver
white, which transitions to grayish black posteriorly.
Coloration of the holotype in preservative.—Dorsum and
venter uniform grayish black; slightly lighter in color than
found in life.
Variation.—Mensural and meristic variation between the two
examined specimens of Polemon ater are shown in Table 2.
The paratype (PEM R17452) was a badly damaged adult
female. There were no differences between the two speci-
mens in terms of coloration in preservative, as both were
uniform grayish black dorsally and ventrally. The female is
larger (640 mm SVL), has fewer subcaudals (15), and has a
proportionately shorter tail (4.35% of SVL). The largest
known specimen (806 mm SVL) is from Solwezi, Zambia
(Broadley et al., 2003). Ventrals were not counted for the
paratype because it was badly damaged. Literature records of
specimens from southeastern DRC and Zambia report ventral
ranges of 202–242 and subcaudal ranges of 15–24 (de Witte,
1953; Laurent, 1956b; Broadley and Pitman, 1960; Broadley
et al., 2003). Broadley and Pitman (1960) and Broadley et al.
(2003) noted that specimens from Zambia may have one or
two postoculars, and temporal formulas were either 1þ1or
0þ1þ1. De Witte (1953) reported that a specimen from
Upemba National Park in southeastern DRC contained one
postocular on the left side, and two postoculars on the right
side. Specimens from southeastern DRC and Zambia are
reported to be uniformly grayish black, bluish black, or black,
both dorsally and ventrally (de Witte, 1953; Broadley et al.,
2003), but Broadley et al. (2003: 95) noted ventral coloration
‘‘may have varying degrees of white on the neck or belly.’’
Laurent (1956b) noted that a young male specimen from
Dilolo (Lualaba Province, DRC) still had a distinct grayish
collar in preservative, suggesting that juvenile or subadult P.
ater might have a distinct collar. Morphometric and meristic
Fig. 4. Photographs of the holotype of Polemon ater, PEM R20734
(254 mm SVL), subadult male from Fungurume, Lualaba Province,
Democratic Republic of the Congo, in life (photos: CRT). (A) Closeup of
head; (B) anterior body and tongue; (C) entire body.
Portillo et al.—New species of Polemon 27
data for examined specimens of Polemon christyi, P. collaris,
and P. ater are shown in Table 2.
Habitat.—Specimens of P. ater were collected from localities
in or near Brachystegia (i.e., miombo) woodlands of Lualaba
Province, DRC (Fig. 7). The paratype was found dead in a pit
in Kalakundi Copper Mine, where it had been killed by mine
workers. Specimens from Upemba National Park in south-
eastern DRC were found in grassland-miombo woodland
habitat near tributaries. Specimens from Zambia were found
in miombo woodland and in some cases, there was gallery
forest in the vicinity, although none of the specimens were
found in gallery forests (Broadley et al., 2003). Specimens for
this study were found in elevations ranging from 1189–1472
m. In Upemba National Park, de Witte (1953) found a male
specimen as high as 1810 m.
Natural history.—Very little is known about the ecology and
natural history of this species. Upon discovery at about 20:00
hrs, the behavior of the holotype was described as ‘‘atractas-
poid,’’ but it did not produce the neck flexure posturing that
is typical for Atractaspis snakes that are in a defensive mode.
However, ‘‘it did thrash and jerk, freeze with body dorso-
ventrally flattened, and occasionally display a small degree of
neck flexion’’ (Tilbury and Branch, 2014: 36). The holotype
was kept in captivity for some time after capture, during
which it burrowed into soil of its container, but it preferred to
shelter under pieces of bark at the surface of the soil. The
animal refused offerings of food including earthworms,
grasshoppers, newly-metamorphosed toadlets, and geckos
(Hemidactylus mabouia and Lygodactylus gutturalis), but even-
tually it ate one L. gutturalis gecko (Tilbury and Branch,
2014).
Based on the natural history of other species of Polemon,P.
ater is likely nocturnal and fossorial, although Hinkel and
Fischer (1988) noted that P. christyi in Rwanda can be diurnal
or nocturnal. The new species is known to consume snakes
that are relatively large. The paratype (PEM R17452) was
found with a very large (480 mm SVL) Afrotyphlops schmidti
(PEM R17440) in its gut. The Afrotyphlops schmidti was about
halfway consumed, but the thickness of this prey item (14.8
mm) exceeded the thickness of the specimen of P. ater (9.8
mm). Broadley et al. (2003) reported a 806 mm P. ater (as P.
christyi) that consumed a 600 mm Crotaphopeltis hotamboeia
and a 430 mm P. ater that consumed a 305 mm C. hotamboeia.
Broadley et al. (2003) reported that Zambian specimens were
usually seen at night after heavy rainfall. Spawls et al. (2018)
noted this species may be found in leaf litter or below the
surface, and it emerges from underground during the rainy
season. Additionally, Spawls et al. (2018) stated that the
species is known to consume Afrotyphlops,Leptotyphlops, and
C. hotamboeia.Polemon ater is thought to lay eggs, but no
clutch details are known (Hinkel and Fischer, 1988; Spawls et
al., 2018).
Distribution.—The new species most likely occurs in south-
eastern DRC, Zambia, west-central Tanzania, and possibly as
far north as Burundi (Broadley and Howell, 1991; Caro et al.,
2011; Spawls et al., 2002, 2004, 2018; Tilbury and Branch,
2014). Specimens noted from Rwanda and Malawi (some of
Fig. 5. Line drawings of lateral views of the (A) holotype of Polemon ater (PEM R20734), (B) holotype of P. christyi (BMNH 1946.1.8.88), (C)
holotype of P. collaris (ZMB 10045), and (D) paratype of P. gabonensis (BMNH 1946.1.3.4). Scale bars represent 2 mm.
28 Copeia 107, No. 1, 2019
which were found in elevations above 1995 m; de Witte,
1941; Laurent, 1956a; Hinkel and Fischer, 1988; Mercurio,
2007) may be attributable to P. christyi,P. ater, or an unknown
species. Specimens noted from northeastern DRC, Uganda,
South Sudan, and western Kenya are attributable to P. christyi
(Tilbury and Branch, 2014; Wallach et al., 2014; Spawls et al.,
2018), but some populations (e.g., Virunga National Park,
DRC) require additional study to confirm their identification.
Etymology.—Derived from the Latin atrum in reference to the
grayish black or black dorsal and ventral coloration that is
present in all known specimens of P. ater.
DISCUSSION
Polemon ater is one of only a few lamprophiid species to be
described from Central Africa in recent years (e.g., Green-
baum et al., 2015; Trape and Mediannikov, 2016) and the
first species described from the genus in over 70 years.
Micrelaps tchernovi was described in 2006, but in recent
phylogenetic analyses, the genus was recovered outside the
subfamily Aparallactinae (Figueroa et al., 2016; Portillo et al.,
2018). As is the case with most species of aparallactines,
morphological conservatism is common within Polemon.
Meristic characters for several species (e.g., P. collaris,P.
christyi, and P. ater) display considerable overlap, making
specimens difficult to distinguish (Table 2). These species are
most easily distinguished by coloration (presence of an
orange or yellow collar, presence of dorsal stripes), head
shape, and head scalation shape (Figs. 4–6).
Morphologically, the most similar species to the newly
described P. ater is P. christyi, but the latter species is not sister
to the former one, and was recovered in a well-supported
clade with P. robustus (Fig. 1; Portillo et al., 2018). The latter
study lacked genetic samples of P. gabonensis, but morpho-
logically, P. gabonensis is readily distinguished by its large,
broad snout (Figs. 5, 6; de Witte and Laurent, 1947).
Moreover, P. gabonensis also has a distinct, creamy yellow
venter that easily distinguishes it from P. ater, and the former
species is only known from lowland rainforest, a habitat that
is distinct from the miombo woodland/savanna habitat of P.
ater (Broadley and Howell, 1991; Broadley et al., 2003;
Chippaux, 2006; Chirio and LeBreton, 2007; Pauwels and
Vande weghe, 2008; Portillo et al., 2018; Spawls et al., 2018).
Polemon ater is genetically most similar to P. collaris, and the
sister relationship between the two species was strongly
supported in maximum likelihood (RAxML) and Bayesian
inference (MrBayes and BEAST) analyses (Fig. 1; Portillo et al.,
2018). Morphologically, the two species can usually be
distinguished by the grayish black or black dorsal and ventral
coloration of P. ater. This contrasts with the vibrant yellow or
cream collar (that may fade with age) and contrasting,
creamy white venter that seems ubiquitous in many adult
specimens of P. collaris (de Witte and Laurent, 1947; FP, pers.
obs.). Polemon collaris was described from ‘‘Macange’’
(¼Malanje, Malanje Prov., N Angola, 098330S, 168200E) and
Fig. 6. Line drawings of dorsal views of the (A) holotype of Polemon ater (PEM R20734), (B) holotype of P. christyi (BMNH 1946.1.8.88), (C)
holotype of P. collaris (ZMB 10045), and (D) paratype of P. gabonensis (BMNH 1946.1.3.4). Scale bars represent 2 mm.
Portillo et al.—New species of Polemon 29
characterized (in part, and as its name implies) by a pale
collar. An anomalous Angolan sample (PEM R19893), with a
very faded grayish collar, grayish black dorsum, and grayish
black, white-edged ventrals, showed substantial genetic
differentiation (i.e., long branch length) from P. ater and
other samples of P. collaris from DRC (Fig. 1). Its relationship
to other Angolan populations possessing a pale collar (e.g.,
from Malanje, Cazengo ,and Pungo-Andongo) awaits further
study (de Witte and Laurent, 1947; FP, pers. obs.). A
surprising result from the phylogenetic analyses of Portillo
et al. (2018) was the placement of P. christyi, which was
recovered as sister to P. robustus.Polemon christyi,P. collaris,P.
gabonensis, and P. ater all have similar ranges of ventral scale
counts, yet P. christyi was found to be more closely related to
P. robustus (Portillo et al., 2018), which is stockier in build and
has substantially fewer ventral scales relative to most
congeners (de Witte and Laurent, 1947).
Polemon christyi has been recorded from Uganda, western
Kenya, Virunga National Park (eastern DRC), Upemba
National Park (southeastern DRC), Garamba National Park
(northeastern DRC), Lualaba Province (DRC), Central African
Republic (record considered doubtful sensu Chirio and
Ineich, 2006), Rwanda, Burundi, west-central Tanzania,
Zambia, South Sudan, and northeastern Malawi (Boulenger,
1903, 1911, 1915; de Witte, 1941, 1953, 1955, 1975; de Witte
and Laurent, 1943, 1947; Loveridge, 1944; Laurent, 1955,
1956a, 1956b, 1960; Broadley, 1971; Pitman, 1974; Spawls,
1978; Hinkel and Fischer, 1988; Joger, 1990; Broadley and
Howell, 1991; Meirte, 1992; Vonesh, 2001; Behangana and
Goodman, 2002; Broadley et al., 2003; Chippaux, 2006;
Mercurio, 2007; Caro et al., 2011; Wallach et al., 2014; Spawls
et al., 2018). These records encompass a large geographic area
with multiple habitats in different elevations, and in some
cases, it is not clear whether the specimens are referable to P.
ater,P. christyi, or an unknown species.
Schmidt (1923) described Miodon unicolor (later placed in
the synonymy of P. christyi by de Witte and Laurent, 1947)
based on a single male specimen from lowland rainforest in
Poko (Ituri rainforest), northeastern DRC. This specimen has
202 ventral scales and a uniformly dark bluish gray dorsum,
with ventral scales edged with white. Based on these features
and its locality, the specimen is likely attributable to P. christyi
rather than P. ater. The shape of the nasal and postocular
scales (based on the original description) of Miodon unicolor
also closely matches that of P. christyi (Schmidt, 1923). De
Witte (1941) described Melanocalamus leopoldi based on a
female specimen from montane forest in Rwankeri, Rwanda
(2200 m) with 245 ventral scales and fused preocular and
prefrontal scales. This specimen contains more ventral scales
than the two female specimens of P. christyi examined herein
(but within range of Ugandan specimens, sensu Pitman,
1974), and also fused preocular and prefrontal scales, a trait
that is not exhibited by either P. ater or Ugandan P. christyi.
Laurent (1956a) placed M. leopoldi in the synonymy of P.
christyi, but this action was seemingly rejected by de Witte
(1962), and based on the absence of a preocular (because of
fusion with the prefrontal), Meirte (1992) continued to
recognize the former taxon as a valid species, and he retained
Fig. 7. Photograph of miombo woodland habitat of the paratype of Polemon ater in Kalakundi, Lualaba Province, Democratic Republic of the Congo
(photo: WRB).
30 Copeia 107, No. 1, 2019
Melanocalamus as a subgenus of Polemon. Wagner et al. (2014)
also recognized Polemon leopoldi as a distinct species.
Although Laurent’s (1956a) action has been accepted by
most authorities (e.g., Wallach et al., 2014; Spawls et al.,
2018; Uetz et al., 2018), further examination of Rwandan
populations is needed to determine with certainty whether
M. leopoldi is conspecific with topotypic P. christyi.
Loveridge (1944) noted a specimen of Miodon gabonensis
christyi (¼Polemon christyi) from 4600 feet (1402 m) at Ilolo,
located in present-day Ruaha National Park, Tanzania. No
distinctive morphological features were noted by Loveridge
(1944) for this specimen (MCZ R30401), and because the
park contains both miombo woodland and evergreen forest
(Mtui et al., 2016), further study is needed to determine the
taxonomic status of this population. Several illustrations of
the head of a specimen of P. christyi (RGMC 9809) from
Usumbura (¼Bujumbura), Burundi were shown by de Witte
and Laurent (1947: figs. 67–69), and Laurent (1960) provided
additional records from Uvira and nearby Makobola (DRC)—
these records are intriguing because they are in a floodplain
near the shore of Lake Tanganyika (EG, pers. obs.), although
it is possible that some gallery forest was intact at the time of
collection. Polemon christyi has also been recorded from
Garamba National Park in northeastern DRC, but the specific
locality and habitat where the specimen was found were not
noted by de Witte (1966). Although the park is dominated by
grasslands and woodlands, it contains some gallery forest
(Hillman Smith et al., 2014). Six specimens of P. christyi
reported by de Witte (1955, 1975) from Virunga National
Park included Mutsora (savanna habitat, 1200 m) and Indray
(‘‘spiny’’ savanna and euphorbia habitat, 900 m), which are
relatively xeric habitats in the park. Mercurio (2007) recorded
a specimen of P. christyi from montane forest (1995 m) in the
Wilindi Forest Reserve, northeastern Malawi. This specimen
has six supralabial scales, unlike P. christyi and P. ater, which
both have seven supralabials (Boulenger, 1903; de Witte,
1941, 1953; de Witte and Laurent, 1943, 1947; Laurent,
1956a, 1960; Pitman, 1974; Meirte, 1992; Broadley et al.,
2003; Chippaux, 2006; Mercurio, 2007), but otherwise it has
similar morphology. Further genetic and morphological
examination of the Malawi population is needed to deter-
mine whether it represents P. christyi,P. ater, or an unknown
species. The montane forest records of P. c h r i s t y i from
Rwanda (de Witte, 1941) and Malawi (Mercurio, 2007) were
both found at higher elevations (2200 m and 1995 m,
respectively) than the known elevational range of P. ater
(1189–1810 m) or P. christyi (600–1760 m; de Witte, 1941,
1953; Pitman, 1974; Broadley et al., 2003; Mercurio, 2007;
Spawls et al., 2018). We thus restrict the known range of P.
christyi to forests, and possibly grasslands, woodlands, and
savannas, of northeastern DRC, Uganda, South Sudan, and
western Kenya. Additional work is needed on the species
complex, but because specimens are rare and fieldwork in
DRC is problematic for many reasons (Greenbaum, 2017), it
will likely be many years before all of these populations can
be examined with molecular data.
The BEAST results from Portillo et al. (2018) suggested that
P. ater and P. christyi last shared a common ancestor during
the early to mid-Miocene (around 16 mya), which coincided
with a climactic optimum (Couvreur et al., 2008; Feakins and
Demenocal, 2010). These results also indicated that P. ater
diverged from its sister taxon, P. collaris, during the late
Miocene (ca. 6 mya), when increasingly cool and arid
conditions throughout central and eastern Africa likely
fragmented populations of many squamates, eventually
leading to their speciation (Greenbaum et al., 2018). Other
Central African snake groups with similar dates of divergence
between sister taxa include the lamprophiid genus Boaedon
and viperid genus Atheris (Menegon et al., 2014; Greenbaum
et al., 2015).
Interestingly, the species of Polemon that are morpholog-
ically similar to P. ater (P. christyi, P. collaris, and P. gabonensis)
are mainly inhabitants of rainforests. Specifically, Polemon
christyi is known from rainforests and associated forest relicts
in Uganda, but it might occur in grasslands and woodlands
in Garamba National Park, DRC (de Witte, 1966; Pitman,
1974). Polemon ater inhabits southeastern Lualaba, Haut-
Katanga, and Haut-Lomami provinces of DRC, and Zambia,
which are dominated by grasslands and miombo woodlands
(de Witte, 1953; Broadley et al., 2003). Within Lualaba, Haut-
Katanga, and Haut-Lomami provinces, plant species richness
was highest within the miombo ecoregion (Broadley and
Cotterill, 2004), and several unique species of reptiles are
known from the region (e.g., Greenbaum et al., 2012; Medina
et al., 2016). Polemon ater might have adapted to the miombo
woodlands and savannas when arid climates in Africa
increased after 9.6 mya (Feakins and DeMenocal, 2010).
Many non-forest habitats in southeastern DRC that are
potential habitats of P. ater and other aparallactines (FP,
unpubl. data) are exposed to degradation because of poor
farming management, uncontrolled fires, mining, and other
environmental degradation linked to human population
growth. Because of these factors, these habitats are constant-
ly at risk, especially unprotected regions in southeastern DRC
miombo woodlands and savannas (Sodhi et al., 2007;
Herrmann and Branch, 2013). Additionally, southeastern
DRC is known to harbor high species diversity of plants,
amphibians, reptiles, and birds (Broadley and Cotterill, 2004;
Greenbaum et al., 2012; Larson et al., 2016; Medina et al.,
2016). Given the results herein and from Portillo et al.
(2018), it is likely that P. ater is endemic to the grasslands,
miombo woodlands, and possibly forests of southeastern
DRC, Zambia, and west-central Tanzania. Possible popula-
tions in Rwanda, Burundi, and Malawi require further study.
Given the proximity of the Dilolo locality (Laurent, 1956b)
to the border of DRC, P. ater is likely to be found in
neighboring Angola.
MATERIAL EXAMINED
* Indicates type specimens. Institutional abbreviations follow
Sabaj (2016), with the Royal Museum for Central Africa,
Tervuren listed as RMCA R and the Royal Belgian Institute of
Natural Sciences listed as RBINS.
Polemon acanthias: ZMB 51389, West Africa.
Polemon bocourti: MNHN-RA 1896.0553–54*, Vallee de
l’Ogoone, Congo.
Polemon christyi: BMNH 1946.1.8.88*, Uganda; CAS 111863,
Mabira Forest, Uganda; CAS 147905, Kakamega Forest,
Kenya; CAS 204334, road between Kibale National Park and
Fort Portal, near Kibale National Park turnoff, Uganda; UTEP
21618, road to Budongo Central Forest Reserve, Western
Region, Uganda, 01.653578N, 31.328068E, 1084 m.
Polemon collaris: PEM R19893, Lunda Norte, Angola,
9.399228S, 20.413238E; UAC 62 (RBINS 18544), Yoko, DRC,
1.93008N, 25.25258E; UTEP 21612, Byonga, South Kivu,
Portillo et al.—New species of Polemon 31
DRC, 03.336948S, 28.124198E, 710 m; UTEP 21613, Fizi,
South Kivu, DRC, 04.274708S, 28.929308E, 1268 m; UTEP
21614, Salonga River, Watsi Kengo, Tshuapa, DRC,
00.910068S, 20.620768E, 332 m; ZMB 10045*, Kwango River,
Angola; ZMB 20308, Cameroon.
Polemon collaris longior: RMCA R 1629*, Medje, DRC; RMCA R
15843*, Lutunguru, DRC.
Polemon fulvicollis: MNHN-RA 1886.0211*, Congo Brazza-
ville, Franceville.
Polemon fulvicollis laurenti: RMCA R 4771*, Tongo, DRC;
RMCA R 15430, Stanleyville (i.e., Kisangani), DRC; RMCA R
18246, Katche, Kivu, DRC; RMCA R 21569, Kivu, DRC; UTEP
21615, Bombole village, Bas-Uele, DRC, 02.278058N,
25.146798E, 467 m.
Polemon gabonensis: BMNH 1946.1.3.4, 5*, Cameroon Moun-
tains, Cameroon; RMCA R 16087, Ibembo, DRC; RMCA R
16545, Bokoro, DRC; RMCA R 21030, Ikela, DRC; ZMB
21142, Cameroon.
Polemon gabonensis brachyurus: RMCA R 20326*, Idjwi Sud,
DRC.
Polemon gabonensis schmidti: RMCA R 8008*, Stanleyville (i.e.,
Kisangani), DRC; RMCA R 10545*, Karawa, Ubangi, DRC.
Polemon graueri: CRT 4007 (RBINS 18543), Bomane, DRC,
1.2708N, 23.7328E; UTEP 21611, Rwenzori Mountains Na-
tional Park, near Nyakalengisa entrance, Uganda,
00.362478N, 29.998638E, 2075 m; UTEP 21650, Idjwi Island,
Bugarula, South Kivu, DRC, 02.058158S, 029.057918E, 1541
m; ZMB 20721*, Entebbe, Uganda.
Polemon griseiceps: BMNH 1946.1.21.90*, Bitye, South Came-
roon.
Polemon notatus: ZMB 10271*, West Africa.
Polemon robustus: RMCA R 6803, 6851, 8761, 11839*,
Kunungu, DRC; UTEP 21616, Lake Mai-Ndombe, Isongo,
Mai-Ndombe, DRC, 01.342228S, 18.237748E, 309 m; UTEP
21617, Salonga River, Itala Village, Equateur, DRC,
00.626158S, 20.208968E, 322 m.
DATA ACCESSIBILITY
Supplemental material is available at https://www.
copeiajournal.org/ch-18-098.
ACKNOWLEDGMENTS
Fieldwork by the last author in DRC was funded by the Percy
Sladen Memorial Fund, an IUCN/SSC Amphibian Specialist
Group Seed Grant, K. Reed, M.D., research funds from the
Department of Biology at Villanova University, a National
Geographic Research and Exploration Grant (no. 8556-08),
UTEP, and the US National Science Foundation (DEB-
1145459); E. Greenbaum, C. Kusamba, W. M. Muninga,
and M. M. Aristote thank their field companions M. Zigabe,
A. M. Marcel, M. Luhumyo, J. and F. Akuku, F. I. Alonda, and
the late A. M’Mema. The Centre de Recherche en Sciences
Naturelles and Institut Congolais pour la Conservation de la
Nature provided project support and permits. Fieldwork by Z.
T. Nagy in DRC was supported by the Belgian National Focal
Point to the Global Taxonomy Initiative. D. F. Hughes, E.
Greenbaum, and M. Behangana thank the Uganda Wildlife
Authority of Kampala for necessary permits to work in
Uganda. W. R. Branch thanks the National Research
Foundation of South Africa (NRF) for funding, and Thomas
Branch for collecting important specimens in northeastern
Angola during mine exploration in the region. We thank W.
Conradie of Port Elizabeth Museum for facilitating loans of
specimens and providing measurement data for a prey item
of the paratype of P. ater. F. Portillo and E. Greenbaum thank
Danny Meirte of the Royal Museum for Central Africa for
facilitating access to specimens and correcting crucial details
of this paper. It is with great sadness that we note that our
friend and colleague Prof. William Roy Branch did not live to
see the publication of this manuscript. His passing is a huge
loss to the many colleagues who treasured his friendship,
advice, and counsel. We salute him as a true giant of African
herpetology.
LITERATURE CITED
Anderson, C. G., and E. Greenbaum. 2012. Phylogeography
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