Corresponding author: J. Maximilian Dehling (
Academic editor: Franco Andreone
We assess the diversity of
Ridged Frogs of the genus
In order to clarify how many and which species occur in Rwanda, we re-examined the specimens of
We examined voucher specimens deposited at RMCA. Additional specimens including our recently collected material are deposited in the collection of the Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany
For the morphological analysis, we took the following 18 measurements to the nearest 0.1 mm using digital calipers, following
Descriptive statistics depended on the outcome of the test for normality. Normally distributed data were described by the arithmetic mean and corresponding standard error and/or range, those deviating significantly by median and range. Principal component analyses were run on the morphometric data set including 18 variables and 89 observations each (
We isolated DNA from a liver tissue sample from a specimen of
Examination of specimens suggested that five morphologically distinct species were present in Rwanda to which we assign the following names:
Males of
The morphometric features of the five species are summarized in
Morphological shape differentiation among 89 specimens representing five
Morphological shape differentiation among 89 specimens representing five
The five Rwandan species can be distinguished unequivocally from each other using a combination of qualitative morphological characters (
Volar view of hands (top) and plantar view of feet (bottom) of males of
Distinguishing qualitative characters of
Species |
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relative length of Toes III and V | tips reaching to knee or slightly beyond, distal subarticular tubercle never reaching knee | tips reaching beyond knee, distal subarticular tubercle reaching knee | tips reaching beyond knee, distal subarticular tubercle reaching knee or beyond | tips reaching to knee or slightly beyond, distal subarticular tubercle never reaching knee | tips reaching to knee or slightly beyond, distal subarticular tubercle never reaching knee |
position of vocal sac aperture | inferior, at ventral edge of arm insertion | inferior, at ventral edge of arm insertion | superior, above dorsal edge of arm insertion | inferior, at ventral edge of arm insertion | semi-inferior, at level of centre of arm insertion |
spiny tubercles on venter | absent | present in males, very small | absent | present in males, comparatively large | present in males, very small |
median dorsal ridge on snout | absent | absent | absent | absent | present |
outer metatarsal tubercle | very faintly visible | very faintly visible, rarely distinct | distinctly present, rarely faintly visible | faintly visible, rarely distinct | faintly visible |
inner metatarsal tubercle size ( |
about half the length of metatarsus of Toe I | less than half the length of metatarsus of Toe I | less than half the length of metatarsus of Toe I | more than half the length of metatarsus of Toe I | about half the length of metatarsus of Toe I |
supernumerary metacarpal tubercles ( |
one below each finger | one below each finger | only one below Finger IV, often indistinct | one below Fingers I, II, and IV; two, rarely one below Finger III | one below Fingers I and IV, two below Finger II, two to four below Finger III |
palmar and thenar tubercles ( |
inner and outer palmar tubercle more or less equal in length; thenar tubercle oval, slightly longer than palmar tubercles | outer palmar tubercle longer than inner; thenar tubercle elongate, about as long as outer palmar tubercle | outer palmar tubercle longer than inner; thenar tubercle elongate, about as long as outer palmar tubercle | outer palmar tubercle longer than inner; thenar tubercle elongate, longer than outer palmar tubercle | inner and outer palmar tubercle more or less equal in length; thenar tubercle elongate, longer than palmar tubercles |
toe webbing ( |
I0.5-2II0.5-2III(0.5-1)-2IV2-0.5V | I2-2.5II(1.5-1.75)-3III(2-2-)(3.25-3+)IV3-(1.5-2)V | I(1.5-1.75)-(2-2.25)II1.5-(2.75-3)III(1.75-2)-3IV2.75-(1-1.5)V | I(1.75-2)-2.25II1.5-3III1.75-(3-3.25)IV3-(1-1.5)V | I2-(2.25-2.5)II1.5-3-III(1.75-2-)-3IV3-(1+-1.25)V |
ventral colouration | head white, trunk yellow | head and trunk yellow | head white, mottled with grey; trunk yellow | head and trunk yellow | colours in life unreported |
dark brown stripe on preaxial side of tibia | absent | present, continuous or almost continuous | absent in most specimens; few specimens with dark mottling, not forming continuous stripe | absent | absent |
light tibial line ( |
absent | usually present, rarely absent | present or absent | present | absent |
light dorsal band | absent | usually present, rarely absent | present or absent | present or absent | present |
dark spots on dorsum<br/> ( |
usually absent; if present, small and narrow | usually present, small and narrow, sometimes forming longitudinal lines; rarely absent | present, large and wide, sometimes fused with neighboring ones | present, large and wide, sometimes fused with neighboring ones | present, large and wide, often fused with neighboring ones |
light, prominent dorsolateral fold ( |
usually absent | present | present | present | present |
Colour pattern on postaxial side of femur | irregularly delimited, reticulated, longitudinal bands, alternately yellow and dark brown coloured | irregularly delimited, reticulated, longitudinal dark bands on light background; colours in life unreported | relatively sharply delimited longitudinal bands, alternately yellow and black coloured | yellow spots diffusely arranged in longitudinal rows on dark brown background | irregularly delimited, reticulated, longitudinal light bands on dark background; colours in life unreported |
Morphometric features of
Morphometric character |
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Males<br/> N = 15 | Females<br/> N = 3 | Males<br/> N = 75/14* | Females<br/> N = 23/11* | Males<br/> N = 13 | Females<br/> N = 10 | Males<br/> N = 11/20* | Females<br/> N = 9 | Males<br/> N = 6 | Females<br/> N = 1 | |
Snout-vent length | 40.4<br/> (38.0–42.4) | 49.0<br/> (46.7–51.3) | 43.3<br/> (36.3–49.5) | 53.7<br/> (48.0–57.7) | 42.0<br/> (37.2–45.2) | 49.1<br/> (45.6–53.1) | 41.2*<br/> (37.3–44.5) | 46.4<br/> (39.0–52.1) | 34.7<br/> (33.3–35.7) | 43.3<br/> - |
Hindlimb length | 79.6<br/> (74.2–84.9) | 98.9<br/> (96.0–101.2) | 88.1<br/> (83.5–93.0) | 108.2<br/> (102.3–114.1) | 77.2<br/> (70.1–85.2) | 89.6<br/> (78.0–103.9) | 78.2*<br/> (72.8–85.5) | 88.3<br/> (74.3–94.1) | 66.7<br/> (61.9–72.7) | 81.2<br/> - |
Femur length | 23.0<br/> (21.9–24.5) | 29.0<br/> (28.3–29.6) | 23.9<br/> (22.5–25.0) | 29.9<br/> (28.1–32.0) | 21.5<br/> (19.4–24.0) | 25.5<br/> (23.0–28.5) | 21.7*<br/> (20.2–24.1) | 24.4<br/> (19.8–27.6) | 18.7<br/> (17.2–19.6) | 23.1<br/> - |
Tibiofibula length | 26.3<br/> (24.4–28.0) | 33.1<br/> (31.9–33.8) | 28.4<br/> (24.6–32.0) | 35.2<br/> (32.4–38.5) | 23.4<br/> (21.1–26.1) | 27.5<br/> (23.6–32.1) | 24.7*<br/> (23.3–26.5) | 28.7<br/> (25.2–31.0) | 21.7<br/> (20.3–23.4) | 26.9<br/> - |
Tarsus length | 34.5<br/> (31.6–36.5) | 42.7<br/> (40.6–44.1) | 40.9*<br/> (38.9–44.1) | 49.3*<br/> (46.5–51.3) | 36.2<br/> (32.4–40.1) | 42.8<br/> (35.9–49.6) | 35.5<br/> (33.3–38.8) | 40.0<br/> (32.6–43.5) | 30.5<br/> (27.9–32.2) | 36.0<br/> - |
Foot length | 24.7<br/> (22.4–26.1) | 30.5<br/> (29.1–31.3) | 28.4<br/> (24.2–30.4) | 34.5<br/> (32.9–36.1) | 25.7<br/> (22.8–28.2) | 29.3<br/> (25.6–33.9) | 24.4<br/> (23.0–26.7) | 27.4<br/> (23.1–29.3) | 21.0<br/> (19.5–21.9) | 28.6<br/> - |
Forelimb length | 16.9<br/> (15.9–18.1) | 21.0<br/> (20.0–21.7) | 18.3*<br/> (17.4–19.1) | 22.0*<br/> (20.9–23.9) | 17.7<br/> (16.0–19.3) | 20.5<br/> (17.9–23.7) | 17.2<br/> (16.0–18.6) | 18.7<br/> (16.1–20.9) | 13.5<br/> (12.8–14.4) | 16.3<br/> - |
Hand length | 10.0<br/> (9.5–10.7) | 12.3<br/> (12.1–12.6) | 10.4*<br/> (9.6–11.1) | 12.4*<br/> (11.8–13.3) | 10.4<br/> (9.5–11.6) | 11.9<br/> (10.6–13.8) | 9.7<br/> (8.9–10.8) | 10.7<br/> (9.1–11.7) | 7.9<br/> (7.4–8.5) | 9.0<br/> - |
Head width | 13.8<br/> (12.5–15.4) | 16.7<br/> (16.4–17.0) | 13.9<br/> (12.8–14.7) | 16.9<br/> (15.4–17.5) | 13.8<br/> (12.4–15.9) | 16.4<br/> (14.2–18.8) | 14.1<br/> (13.1–15.0) | 15.1<br/> (12.5–17.1) | 11.4<br/> (11.0–11.7) | 13.8<br/> - |
Head length | 15.5<br/> (14.1–17.6) | 18.7<br/> (18.2–19.1) | 15.6*<br/> (14.7–16.4) | 18.6*<br/> (17.9–19.8) | 16.2<br/> (14.7–18.4) | 18.3<br/> (16.6–20.4) | 15.5<br/> (14.2–17.8) | 17.1<br/> (13.6–19.1) | 13.3<br/> (12.3–14.0) | 16.1<br/> - |
Interorbital distance | 2.8<br/> (2.4–3.1) | 3.1<br/> (3.0–3.2) | 3.5*<br/> (3.1–3.9) | 4.1*<br/> (3.8–4.5) | 2.2<br/> (1.9–2.5) | 2.5<br/> (2.2 - 2.7) | 2.6<br/> (2.3–2.7) | 3.1<br/> (2.8–3.6) | 2.7<br/> (2.4–3.1) | 2.9<br/> - |
Eyelid width | 2.8<br/> (2.5–3.1) | 3.2<br/> (3.0–3.3) | 2.7*<br/> (2.4–3.0) | 3.3*<br/> (2.9–3.7) | 2.7<br/> (2.3–3.2) | 3.0<br/> (2.4–3.5) | 2.8<br/> (2.3–3.1) | 3.1<br/> (2.6–3.5) | 2.6<br/> (2.3–2.8) | 2.4<br/> - |
Eye diameter | 4.3<br/> (3.6–4.9) | 5.2<br/> (5.0–5.5) | 4.3<br/> (3.7–4.9) | 5.0<br/> (4.6–5.6) | 4.5<br/> (4.1–5.1) | 5.1<br/> (4.8–5.5) | 4.2<br/> (3.9–4.5) | 4.6<br/> (3.9–5.1) | 3.9<br/> (3.6–4.1) | 4.5<br/> - |
Tympanum diameter | 3.3<br/> (2.9–3.6) | 4.1<br/> (3.7–4.6) | 3.7<br/> (3.2–4.2) | 4.5<br/> (4.3–5.1) | 3.7<br/> (3.3–4.1) | 4.1<br/> (3.7–4.7) | 3.1<br/> (2.9–3.49 | 3.6<br/> (3.3–3.9) | 2.9<br/> (2.5–3.3) | 3.5<br/> - |
Eye–nostril distance | 4.1<br/> (3.7–4.3) | 5.2<br/> (4.9–5.7) | 3.9*<br/> (3.5–4.4) | 4.6*<br/> (4.0–5.0) | 3.6<br/> (3.4–4.0) | 4.2<br/> (3.7–4.9) | 3.5<br/> (3.1–3.9) | 4.2<br/> (3.6–4.7) | 3.5<br/> (3.2–3.6) | 4.2<br/> - |
Snout–nostril distance | 3.5<br/> (2.9–4.0) | 4.4<br/> (4.3–4.5) | 3.9*<br/> (3.5–4.3) | 4.3*<br/> (3.9–4.9) | 3.4<br/> (2.9–3.8) | 3.7<br/> (3.3–4.1) | 3.4<br/> (2.9–3.7) | 4.1<br/> (2.8–4.7) | 3.6<br/> (3.2–3.9) | 4.3<br/> - |
Internarial distance | 3.9<br/> (3.5–4.3) | 4.8<br/> (4.7–4.9) | 4.3*<br/> (4.0–4.5) | 4.9*<br/> (4.5–5.2) | 3.4<br/> (3.0–3.6) | 3.7<br/> (2.0–4.5) | 3.6<br/> (3.4–4.0) | 4.3<br/> (3.7–4.7) | 3.0<br/> (2.9–3.2) | 3.7<br/> - |
Snout length | 7.5<br/> (6.6–8.1) | 9.5<br/> (9.0–10.1) | 7.4*<br/> (7.0–7.9) | 8.7*<br/> (8.4–9.4) | 7.0<br/> (6.3–7.7) | 7.9<br/> (7.1–9.3) | 7.0<br/> (6.3–7.8) | 8.1<br/> (6.2–10.1) | 6.7<br/> (6.4–7.0) | 8.0<br/> - |
Principal component Analysis based on 18 standardized morphometric features of 89 specimens belonging to five
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1 | 13.84 | 76.9 | 76.9 |
2 | 1.46 | 8.1 | 85.0 |
3 | 0.82 | 4.6 | 89.6 |
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Snout-vent length | 0.256 | -0.107 | -0.084 |
tibiofibula length | 0.253 | 0.212 | -0.011 |
foot length | 0.255 | 0.046 | -0.278 |
tarsus + foot length | 0.257 | 0.056 | -0.246 |
total hindlimb length | 0.261 | 0.109 | -0.137 |
thigh length | 0.260 | 0.048 | -0.033 |
forearm + hand length | 0.253 | -0.164 | -0.210 |
hand length | 0.244 | -0.231 | -0.139 |
head width | 0.243 | -0.224 | -0.016 |
head length | 0.232 |
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0.105 |
interorbital distance | 0.171 |
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-0.237 |
upper eyelid width | 0.201 | -0.142 | 0.272 |
horizontal eye diameter | 0.211 | -0.325 | 0.162 |
horizontal tympanum diameter | 0.231 | -0.112 | -0.284 |
eye to nostril distance | 0.228 | 0.016 |
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nostril to snout distance | 0.195 |
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snout length | 0.234 | 0.070 |
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internarial distance | 0.227 |
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0.072 |
Gender-specific discriminant functions based on 17 SVL-adjusted morphometric features (residuals) to distinguish among five
Discriminant function | Eigen-value | Relative percentage | Canonical correlation | Wilks Lambda | Chi-squared | Degrees of freedom | Statistical significance |
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Male 1 | 19.79 | 58.76 | 0.975 | 0.0003 | 362.2 | 68 | P < 0.0001 |
Male 2 | 8.49 | 25.23 | 0.945 | 0.0079 | 222.6 | 48 | P < 0.0001 |
Male 3 | 3.29 | 9.77 | 0.875 | 0.0750 | 119.0 | 30 | P < 0.0001 |
Male 4 | 2.10 | 6.24 | 0.823 | 0.3223 | 52.0 | 14 | P < 0.0001 |
Female 1 | 45.49 | 65.38 | 0.989 | 0.00005 | 187.7 | 68 | P < 0.0001 |
Female 2 | 14.84 | 21.33 | 0.967 | 0.0023 | 114.7 | 48 | P < 0.0001 |
Female 3 | 6.87 | 9.89 | 0.934 | 0.0377 | 62.2 | 30 | P < 0.0001 |
Female 4 | 2.36 | 3.40 | 0.838 | 0.2973 | 23.0 | 14 | P = 0.0596 |
Gender-specific discriminant functions based on 17 SVL-adjusted morphometric features (residuals) to distinguish among five
parameter (residuals) | discriminant function 1<br/> (males) | discriminant function 2<br/> (males) | discriminant function 3<br/> (males) | discriminant function 4<br/> (males) | discriminant function 1<br/> (females) | discriminant function 2<br/> (females) | discriminant function 3<br/> (females) | discriminant function 4<br/> (females) |
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tibiofibula length |
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-0.221 | 0.302 | 0.871 | 0.824 | -0.143 | 0.196 | 0.384 |
foot length | 0.268 | -0.253 | 0.292 |
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tarsus + foot length |
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-0.026 |
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-0.410 |
total hindlimb length | 0.310 | -0.029 | -0.147 |
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-0.617 | 0.188 | 0.361 |
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thigh length | 0.161 |
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0.367 | -0.108 | 0.750 | 0.009 | -0.268 | 0.196 |
forearm + hand length | -0.172 | 0.142 |
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-0.005 | 0.468 | -0.492 | 0.483 | 0.105 |
hand length |
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-0.506 | 0.383 | -0.189 | -0.879 | -0.007 | 0.088 | 0.328 |
head width | 0.009 | -0.137 | -0.370 | 0.326 | -0.778 |
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0.472 | 0.534 |
head length | -0.282 | -0.341 | 0.252 | -0.389 | -0.293 |
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-0.563 | -0.734 |
interorbital distance | 0.366 | 0.144 | 0.285 | 0.136 |
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0.561 | -0.269 | -0.019 |
upper eyelid width | -0.022 | 0.315 | -0.221 | 0.328 |
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0.473 |
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-0.234 |
horizontal eye diameter | -0.296 | -0.048 | 0.420 | -0.193 |
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0.232 |
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0.089 |
eye to nostril distance | 0.417 | -0.532 | 0.473 | -0.287 |
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-0.555 | 0.242 | -0.166 |
nostril to snout distance | 0.072 | 0.529 | 0.225 | 0.124 | 1.162 | -0.599 | 0.727 | -0.818 |
snout length | -0.291 | -0.063 | -0.123 | 0.422 | -0.176 | 0.035 | -0.337 | 0.767 |
internarial distance |
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0.135 |
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-0.567 | 0.594 | 0.087 | -0.026 | -0.213 |
horizontal tympanum diameter | -0.052 | -0.157 |
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-0.187 |
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0.088 | -0.621 | 0.488 |
Constant | 0.909 | -0.222 | 0.302 | 0.871 | 0.824 | -0.143 | 0.196 | 0.384 |
Gender-specific discriminant functions based on 17 SVL-adjusted morphometric features (residuals) to distinguish among five
predicted species<br/> actual species |
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15 (100%)<br/> 3 (100%) | 0 | 0 | 0 | 0 | |
0 | 13 (100%)<br/> 10 (100%) | 0 | 0 | 0 | |
0 | 0 | 13 (100%)<br/> 10 (100%) | 0 | 0 | |
0 | 0 | 0 | 11 (100%)<br/> 7 (100%) | 0 | |
0 | 0 | 0 | 0 | 6 (100%)<br/> 1 (100%) |
1 | external vocal sac apertures and nuptial pads on dorsal side of metacarpals and phalanges of Fingers I–III present | adult males...2 |
– | external vocal sac apertures and nuptial pads absent | adult females and subadults...6 |
2 | vocal sac aperture superior; only one supernumerary metacarpal tubercle proximal to Finger IV, often indistinct; longitudinal, alternately black and yellow coloured bands on postaxial side of femur (spiny tubercles on venter absent; inner metatarsal tubercle less than half the length of metatarsus of Toe I; distal subarticular tubercles of Toes III and V reaching to knee; toe webbing I(1.5–1.75)-(2–2.25)II1.5-(2.75–3)III(1.75–2)-3IV2.75-(1–1.5)V; ventral side of head white, mottled with grey) |
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– | vocal sac aperture inferior or semi-inferior; at least one supernumerary metacarpal tubercle proximal to each finger; colouration on postaxial side of femur different | 3 |
3 | spiny tubercles on venter absent; toe webbing reaching distal phalanx on postaxial sides of Toes I, II, and III and on preaxial side of Toe V; external dorsal ridge usually not light and prominent (vocal sac aperture inferior; distal subarticular tubercles of Toes III and V never reaching knee; inner metatarsal tubercle about half the length of metatarsus of Toe I; ventral side of head white, trunk yellow; light tibial line and light dorsal band absent; dark spots on dorsum usually absent, if present, small and narrow; irregularly delimited, reticulated, longitudinal, alternately yellow and dark brown coloured bands on postaxial side of femur) |
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– | spiny tubercles on venter present; toe webbing not reaching distal phalanges on toes; external dorsal ridge light and prominent | 4 |
4 | median dorsal ridge extending to level between nostrils on dorsal side of snout; vocal sac aperture semi-inferior; two supernumerary metacarpal tubercles proximal to Finger II; inner and outer palmar tubercle more or less equal in length; inner metatarsal tubercle about half the length of metatarsus of Toe I |
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– | median dorsal ridge extending to level between eyelids only; vocal sac aperture inferior; one supernumerary metacarpal tubercle proximal to Finger II; outer palmar tubercle longer than inner; inner metatarsal tubercle either more than or less than half the length of metatarsus of Toe I | 5 |
5 | foot large, tips of Toes III and V reaching distinctly beyond knee, their distal subarticular tubercles reaching knee; ventral tubercles tiny, hardly visible with naked eye; inner metatarsal tubercle less than half the length of metatarsus of Toe I; dark brown stripe present on preaxial side of tibia; thenar tubercle approximately as long as outer palmar tubercle; webbing not reaching beyond distal subarticular tubercle on postaxial side of Toe III; dorsal spots small and narrow; irregularly delimited, reticulated, longitudinal dark bands on light background on postaxial side of femur |
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– | foot smaller, tips of Toes III and V at most reaching slightly beyond knee, their distal subarticular tubercles not reaching knee; ventral tubercles large, visible with naked eye, palpable with finger; inner metatarsal tubercle more than half the length of metatarsus of Toe I; dark brown stripe absent on preaxial side of tibia; thenar tubercle longer than outer palmar tubercle; webbing reaching beyond distal subarticular tubercle on postaxial side of Toe III; dorsal spots large and wide; yellow spots, diffusely arranged in longitudinal rows on dark brown background on postaxial side of femur |
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6 | median dorsal ridge extending to level between nostrils on dorsal side of snout; two supernumerary metacarpal tubercles proximal to Finger II (inner metatarsal tubercle about half the length of metatarsus of Toe I; distal subarticular tubercles of Toes III and V not reaching to knee; toe webbing I2-(2.25–2.5)II1.5-3-III(1.75–2)-3IV3-(1+–1.25)V; light tibial line absent; light dorsal band present; dark spots on dorsum large and wide, often fused with neighboring ones; light, prominent dorsolateral fold present) |
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– | median dorsal ridge extending to level between eyelids only; one or no supernumerary metacarpal tubercle proximal to Finger II | 7 |
7 | toe webbing reaching to distal phalanx on postaxial sides of Toes I, II, and III and on preaxial side of Toe V; light prominent external dorsal ridge usually absent; inner metatarsal tubercle about half the length of metatarsus of Toe I (tips of Toes III and V at most reaching slightly beyond knee, their distal subarticular tubercles not reaching knee; ventral side of head white, trunk yellow; light tibial line and light dorsal band absent; dark spots on dorsum usually absent, if present, small and narrow; irregularly delimited, reticulated, longitudinal, alternately yellow and dark brown coloured bands on postaxial side of femur) |
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– | toe webbing not reaching to distal phalanx on toes; light prominent external dorsal ridge present; inner metatarsal tubercle either less than or more than half the length of metatarsus of Toe I | 8 |
8 | inner metatarsal tubercle more than half the length of metatarsus of Toe I; tips of Toes III and V at most reaching slightly beyond knee, their distal subarticular tubercles not reaching knee; thenar tubercle longer than outer palmar tubercle; yellow spots, diffusely arranged in longitudinal rows on dark brown background on postaxial side of femur |
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– | inner metatarsal tubercle less than half the length of metatarsus of Toe I; tips of Toes III and V reaching distinctly beyond knee, their distal subarticular tubercles reaching knee; thenar tubercle about as long as outer palmar tubercle; colouration on postaxial side of femur not consisting of spots | 9 |
9 | dorsal spots small and narrow; one supernumerary metacarpal tubercle proximal to each finger; ventral side of head and chest yellow; dark brown stripe present on preaxial side of tibia; irregularly delimited, reticulated, longitudinal dark bands on light background on postaxial side of femur; webbing not reaching beyond subarticular tubercle on Toe I |
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– | dorsal spots large and wide; only one supernumerary metacarpal tubercle proximal to Finger IV, often indistinct; ventral side of head and chest white; dark brown stripe on preaxial side of tibia absent, few specimens with dark mottling, not forming continuous stripe; longitudinal, alternately black and yellow coloured bands on postaxial side of femur; webbing reaching beyond subarticular tubercle on Toe I |
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Comparison of the mitochondrial 16S rRNA gene sequences corroborated the status of
Maximum likelihood phylogram of species in the genus
Among the examined material we identified five distinct species of
We did not find any
There is no specimen of
The available evidence indicates that only five species of
There are large series of
Our recent efforts to untangle the diversity of
Permission for field studies, handling and exportation of specimens was kindly issued by the Rwanda Development Board - Tourism & Conservation (RDB; officer in charge: A. Mudakikwa). We would like to thank S. Seidel and K. Rembold (Butare Field Station, University of Koblenz) and E. Fischer (Department of Biology, University of Koblenz) for logistic support. E. Fischer also provided a photograph of
The external morphology of each species is described in the following account. Descriptions are primarily based on Rwandan material. In case of
Body moderately sturdy, widest at temporal region, slightly tapering to groin; head large (HL/SUL 0.36–0.43 in males, 0.37–0.41 in females; HW/SUL 0.31–0.39 in males, 0.33–0.36 in females), longer than wide (HL/HW 1.01–1.26 in males, 1.11–1.13 in females); snout long (SL/HL 0.43–0.53 in males, 0.49–0.53 in females), pointed in dorsal view, rounded in profile, considerably projecting beyond lower jaw, longer than wide (SL/EE 1.08–1.24 in males, 1.30–1.33 in females); canthus rostralis distinct between eye and nostril, straight-lined; loreal region oblique, strongly concave; nostrils rounded, directed dorsolaterally; situated half-way between tip of snout and eye or closer to tip of snout than to eye (EN/NS 0.98–1.33 in males, 1.14–1.27 in females), separated from each other by distance subequal to distance between eye and nostril (NN/EN 0.87–1.05 in males, 0.85–0.96 in females); eyes directed anterolaterally, moderately protruding, relatively small (ED/HL 0.24–0.29 in males, 0.26–0.29 in females), its diameter much shorter than snout (ED/SL 0.50–0.63 in males, 0.53–0.58 in females); interorbital distance more or less equalling upper eyelid width (IO/EW 0.83–1.10 in males, 0.89–1.06 in females) and smaller than internarial distance (IO/NN 0.59–0.83 in males, 0.63–0.67 in females); tympanum and its annulus distinctly visible, separated from eye by about one-fifth to one-third of its diameter (ET/TD 0.21–0.36 in males, 0.19–0.25 in females); tympanum diameter 0.62–0.92 (in males) and 0.74–0.83 (in females) of eye diameter; upper jaw with dentition; choanae small, rounded, located far anterolaterally at margins of roof of mouth; vomer teeth in two short rows, separated from each other by distance about three times length of individual row; tongue long and narrow, bilobed for about one-sixth of its length, free distally for one-fourths its length; median lingual process absent; vocal sac in males paired, lateral; external vocal sac aperture as a longitudinal, posterolaterally orientated slit, inferior, terminating at level of ventral edge of insertion of arms; internal vocal sac apertures rounded, situated close to corner of mouth.
Dorsal surfaces of head, trunk and limbs finely shagreened with many scattered small tubercles; dorsum with five or six longitudinal dermal ridges on each side; median ridge extending from interorbital region almost to vent, postpalpebral and external ridges from level just behind posterior edge of upper eyelid to insertion of leg; laterodorsal ridge extending from level about one snout length posterior to tympanum to groin; dorsal ridges interrupted in few specimens; sacral ridge extending from about one head length anterior to vent either medially to median ridges or between median and postpalpebral ridges to vent, in few specimens absent; external ridge forming anterior part of supratympanic fold; posterior part of supratympanic fold less distinct, branching off from external dorsal ridge posterior to tympanum in wide angle and extending posterolaterally to insertion of arm; infratympanic fold thick and conspicuous, almost straight-lined, extending from ventral edge of eye to level of arm insertion, meeting with supratympanic fold; ventral side of limbs and body smooth except slightly areolate postaxial side of thigh; distinct transverse fold between arms on ventral side; supratympanic fold moderately distinct, angled, extending from posterior corner of eye to point dorsal from arm insertion; infratympanic fold thick and conspicuous, almost straight-lined, extending from ventral edge of eye to level of arm insertion, meeting with supratympanic fold, continued after a small gap in form of large oval tubercle dorsally of posterior end of arm insertion.
Forelimbs moderately sturdy; hand relatively small (HND/SUL 0.23–0.27 in males, 0.25–0.26 in females); tips of fingers rounded, not enlarged into disks but slightly swollen volarly; transverse dorsal skin ridge separating ultimate from other phalanges on each finger; relative length of fingers: I ≤ II < IV < III; subarticular tubercles rounded, well developed, numbering one on Fingers I and II, two on Fingers III and IV, proximal tubercles on Fingers III and IV larger and more prominent than distal ones; finger webbing absent; thenar tubercle distinct, large, flat, oval, slightly more than half as long as metacarpal of Finger I; inner palmar tubercle on proximal half of metacarpal region of Fingers II and III, rounded, flat; outer palmar tubercle on proximal half of metacarpal region of Finger IV, oval, slightly more prominent than inner palmar tubercle; one supernumerary metacarpal tubercle between palmar or thenar tubercles and proximal subarticular tubercles on each finger; callous longitudinal ridges between subarticular tubercles on Fingers III and IV and between subarticular tubercles and finger tips on all fingers; nuptial pads in males covering almost entire dorsal surfaces of Fingers I and II, and proximal portion of dorsal side of Finger III.
Hindlimbs sturdy, very long (LEG/SUL 1.87–2.11 in males, 1.96–2.13 in females); knee reaching slightly beyond insertion of forelimbs and tibio-tarsal articulation reaching almost a head length beyond tip of snout when legs are adpressed forwardly to body; tibiofibula very long (TFL/SUL 0.61–0.68 in males, 0.65–0.72 in females), longer than thigh (TFL/THL 1.09–1.19 in males, 1.13–1.16 in females); heels overlapping each other considerably when knees flexed and thighs held perpendicularly to median plane; two low longitudinal ridges on plantar side of tarsus between heel and metatarsal tubercles; foot shorter than or equal in length to tibiofibula (FOT/TFL 0.85–1.00 in males, 0.91–0.93 in females); relative length of toes: I < II < III < V < IV; toe tips rounded, not enlarged into disks but slightly swollen plantarly; transverse dorsal skin ridge separating ultimate from other phalanges on each toe; subarticular tubercles numbering one on Toes I and II, two on Toes III and V, and three on Toe IV; low callous ridges between subarticular tubercles, and between subarticular tubercles and toe tips; pedal webbing formula
Body moderately sturdy, widest at temporal region, slightly tapering to groin; head large (HL/SUL 0.34–0.38 in males, 0.33–0.37 in females; HW/SUL 0.29–0.34 in males, 0.28–0.34 in females), longer than wide (HL/HW 1.04–1.22 in males, 1.05–1.23 in females); snout long (SL/HL 0.45–0.50 in males, 0.45–0.51 in females), pointed in dorsal view, rounded in profile, considerably projecting beyond lower jaw, longer than wide (SL/EE 1.11–1.28 in males, 1.11–1.37 in females); canthus rostralis distinct between eye and nostril, straight-lined; loreal region oblique, strongly concave; nostrils rounded, directed dorsolaterally; situated more or less half-way between tip of snout and eye (EN/NS 0.87–1.14 in males, 0.93–1.24 in females), separated from each other by distance subequal to or larger than distance between eye and nostril (NN/EN 1.02–1.22 in males, 0.94–1.24 in females); eyes directed anterolaterally, moderately protruding, relatively small (ED/HL 0.27–0.32 in males, 0.26–0.30 in females), its diameter much shorter than snout (ED/SL 0.57–0.66 in males, 0.51–0.66 in females); interorbital distance larger than upper eyelid width (IO/EW 1.12–1.48 in males, 1.09–1.44 in females) and smaller than internarial distance (IO/NN 0.75–0.89 in males, 0.78–0.91 in females); tympanum and its annulus distinctly visible, separated from eye by about one-fourth to two-fifths of its diameter (ET/TD 0.24–0.38 in males, 0.26–0.40 in females); tympanum diameter slightly smaller to subequal to eye diameter (TD/ED 0.76–0.98 in males, 0.85–1.01 in females); upper jaw with dentition; choanae small, rounded, located far anterolaterally at margins of roof of mouth; vomer teeth in two short rows, separated from each other by distance about three times length of individual row; tongue long and narrow, bilobed for about one-fifth of its length, free distally for one-fourth its length; median lingual process absent; vocal sac in males paired, lateral; external vocal sac aperture as a longitudinal, posterolaterally orientated slit, inferior, terminating at level of ventral edge of ventral insertion of arms; internal vocal sac apertures rounded, situated close to corner of mouth.
Dorsal surfaces of head, trunk and limbs finely shagreened; dorsum with five or six longitudinal dermal ridges on each side, median one extending from interorbital region almost to vent, postpalpebral and external ones from level just behind posterior edge of upper eyelid to insertion of leg; laterodorsal ridge extending from level about one snout length posterior to tympanum to groin; sacral ridge extending from about one head length anterior to vent either medially to median ridges or between median and postpalpebral ridges to vent; in few specimens additional sacromedial ridge extending between sacral ridge and median ridge to vent for about half length of sacral ridge; external ridge forming anterior part of supratympanic fold; posterior part of supratympanic fold less distinct, branching off from external dorsal ridge posterior to tympanum in wide angle and extending posterolaterally to insertion of arm; infratympanic fold thick and conspicuous, almost straight-lined, extending from ventral edge of eye to level of arm insertion, meeting with supratympanic fold; ventral side of limbs and body smooth except areolate proximal postaxial-ventral part of thigh; distinct transverse fold between arms on ventral side; ventral side of trunk and head densely covered with more or less evenly scattered tiny, pointed tubercles in males.
Forelimbs moderately sturdy; hand relatively small (HND/SUL 0.22–0.26 in males, 0.21–0.25 in females); tips of fingers rounded, not enlarged into disks but slightly swollen volarly; transverse dorsal skin ridge separating ultimate from other phalanges on each finger; relative length of fingers: I = II < IV < III; subarticular tubercles rounded, well developed, numbering one on Fingers I and II, two on Fingers III and IV, proximal tubercles on Fingers III and IV larger and more prominent than distal ones; finger webbing absent; thenar tubercle prominent, elongated, large, two-thirds length of metacarpal of Finger I; inner palmar tubercle on proximal third of metacarpal region of Fingers II and III, oval, flat; outer palmar tubercle on proximal half of metacarpal region of Finger IV, elongated, slightly more prominent than inner palmar tubercle; one supernumerary metacarpal tubercle between palmar or thenar tubercles and proximal subarticular tubercles on all fingers; low callous longitudinal ridges between subarticular tubercles on Fingers III and IV and between subarticular tubercles and finger tips on all fingers; nuptial pads in males covering almost entire dorsal surfaces of Fingers I and II except distal phalanx, and preaxial half of dorsal side of metacarpal of Finger III.
Hindlimbs sturdy, very long (LEG/SUL 1.94–2.27 in males, 1.93–2.14 in females); knee reaching to insertion of forelimbs and tibio-tarsal articulation reaching slightly more than a snout length beyond tip of snout when legs adpressed forwardly to body; tibiofibula very long (TFL/SUL 0.61–0.73 in males, 0.62–0.70 in females), longer than thigh (TFL/THL 1.13–1.22 in males, 1.13–1.25 in females); heels overlapping each other considerably when knees flexed and thighs held perpendicularly to median body plane; two low longitudinalridges on plantar side of tarsus between heel and metatarsal tubercles; foot subequal in length to tibiofibula (FOT/TFL 0.97–1.07 in males, 0.94–1.03 in females); relative length of toes: I < II < III < V < IV; toe tips rounded, not enlarged into disks but slightly swollen plantarly; transverse dorsal skin ridge separating ultimate from other phalanges on each toe; subarticular tubercles numbering one on Toes I and II, two on Toes III and V, and three on Toe IV; low callous ridges between subarticular tubercles, and between subarticular tubercles and toe tips; pedal webbing formula
Body moderately sturdy, widest at temporal region, slightly tapering to groin; head large (HL/SUL 0.35–0.43 in males, 0.35–0.39 in females; HW/SUL 0.30–0.37 in males, 0.32–0.35 in females), longer than wide (HL/HW 1.10–1.27 in males, 1.06–1.15 in females); snout long (SL/HL 0.38–0.46 in males, 0.40–0.45 in females), pointed in dorsal view, rounded in profile, considerably projecting beyond lower jaw, longer than wide (SL/EE 1.20–1.40 in males, 1.15–1.36 in females); canthus rostralis distinct between eye and nostril, straight-lined; loreal region oblique, moderately concave; nostrils rounded, directed dorsolaterally; situated half-way between tip of snout and eye or closer to tip of snout than to eye (EN/NS 0.99–1.18 in males, 1.05–1.34 in females), separated from each other by distance slightly less than or subequal to distance between eye and nostril (NN/EN 0.82–0.99 in males, 0.87–0.97 in females); eyes directed anterolaterally, moderately protruding, relatively small (ED/HL 0.25–0.32 in males, 0.26–0.29 in females), its diameter shorter than snout (ED/SL 0.60–0.69 in males, 0.59–0.69 in females); interorbital distance smaller to equalling upper eyelid width (IO/EW 0.64–1.03 in males, 0.72–0.90 in females) and smaller than internarial distance (IO/NN 0.55–0.74 in males, 0.57–0.72 in females); tympanum and its annulus distinctly visible, separated from eye by about one-fourth to one-third of its diameter (ET/TD 0.28–0.36 in males, 0.26–0.37 in females); tympanum diameter 0.75–0.88 (in males) and 0.77–0.89 (in females) of eye diameter; upper jaw with dentition; choanae small, rounded, located far anterolaterally at margins of roof of mouth; vomer teeth in two short rows, separated from each other by distance about three times length of individual row; tongue long and narrow, bilobed for about one-sixth of its length, free distally for one-third its length; median lingual process absent; vocal sac in males paired, lateral; external vocal sac aperture as a longitudinal, posteriorly orientated slit, situated dorsally of level of insertion of arms, parallel to mandibel and infratympanic fold, covered by narrow dermal flap on ventral edge of slit; internal vocal sac apertures rounded, situated close to corner of mouth.
Dorsal surfaces of head, trunk and limbs shagreened; dorsum with four or five longitudinal dermal ridges on each side, median one extending from interorbital region almost to vent, postpalpebral and external ones from level just behind posterior edge of upper eyelid to insertion of leg; laterodorsal ridge extending from level about one snout length posterior to tympanum to groin; in few specimens additional very short ridge present between median and postpalpebral ridge from about one snout length anterior to vent extending almost to vent; external ridge forming anterior part of supratympanic fold; posterior part of supratympanic fold less distinct, branching off from external dorsal ridge posterior to tympanum in wide angle and extending posterolaterally to insertion of arm; infratympanic fold thick and conspicuous, almost straight-lined, extending from ventral edge of eye to level of arm insertion, meeting with supratympanic fold; ventral side of limbs and body smooth except areolate postaxial side of thigh; distinct transverse fold between arms on ventral side.
Forelimbs moderately sturdy; hand relatively small (HND/SUL 0.21–0.27 in males, 0.22–0.26 in females); tips of fingers rounded, not enlarged into disks but slightly swollen volarly; transverse dorsal skin ridge separating ultimate from other phalanges on each finger; relative length of fingers: I ≤ II < IV < III; subarticular tubercles rounded, well developed, numbering one on Fingers I and II, two on Fingers III and IV; proximal tubercles on Fingers III and IV larger and more prominent than distal ones; finger webbing absent; thenar tubercle prominent, elongated and narrow, comparatively small, less than half as long as metacarpal of Finger I; inner palmar tubercle small, flat, less conspicuous, on proximal one-third to one-fourth of metacarpal region of Fingers II and III, rounded, flat; outer palmar tubercle on proximal half of metacarpal region of Finger IV, prominent, elongate and narrow; single supernumerary metacarpal tubercle between outer palmar tubercle and proximal subarticular tubercle of Finger IV, often indistinct; callous longitudinal ridges between subarticular tubercles on Fingers III and IV and between subarticular tubercles and finger tips on all fingers; nuptial pads in males covering almost entire dorsal surfaces of Fingers I and II and preaxial half of dorsal surface of Finger III.
Hindlimbs sturdy, long (LEG/SUL 1.71–1.97 in males, 1.76–1.96 in females); knee reaching just behind insertion of forelimbs and tibio-tarsal articulation reaching tip of snout when legs are adpressed forwardly to body; tibiofibula moderately long (TFL/SUL 0.50–0.60 in males, 0.54–0.60 in females), longer than thigh (TFL/THL 1.04–1.12 in males, 1.09–1.12 in females); heels overlapping each other when knees flexed and thighs held perpendicularly to median plane; two low longitudinalridges on plantar side of tarsus between heel and metatarsal tubercles; foot long, longer than tibiofibula (FOT/TFL 1.07–1.14 in males, 1.03–1.10 in females); relative length of toes: I < II < III < V < IV; toe tips rounded, not enlarged into disks but slightly swollen plantarly; transverse dorsal skin ridge separating ultimate from other phalanges on each toe; subarticular tubercles numbering one on Toes I and II, two on Toes III and V, and three on Toe IV; low callous ridges between subarticular tubercles, and between subarticular tubercles and toe tips; pedal webbing formula
Body moderately sturdy, widest at temporal region, slightly tapering to groin; head large (HL/SUL 0.35–0.41 in males, 0.35–0.40 in females; HW/SUL 0.31–0.36 in males, 0.30–0.34 in females), longer than wide (HL/HW 1.02–1.19 in males, 1.03–1.21 in females); snout moderately long (SL/HL 0.38–0.49 in males, 0.43–0.51 in females), pointed in dorsal view, rounded in profile, considerably projecting beyond lower jaw, longer than wide (SL/EE 1.21–1.27 in males, 1.11–1.61 in females); canthus rostralis distinct between eye and nostril, straight-lined; loreal region oblique, strongly concave; nostrils rounded, directed dorsolaterally; situated more or less half-way between tip of snout and eye (EN/NS 0.89–1.15 in males, 0.87–1.29 in females), separated from each other by distance subequal to or larger than distance between eye and nostril (NN/EN 0.96–1.15 in males, 0.96–1.11 in females); eye directed anterolaterally, moderately protruding, relatively small (ED/HL 0.24–0.30 in males, 0.25–0.29 in females), its diameter much shorter than snout (ED/SL 0.54–0.67 in males, 0.51–0.63 in females); interorbital distance subequal to upper eyelid width (IO/EW 0.80–1.09 in males, 0.81–1.10 in females) and smaller than internarial distance (IO/NN 0.65–0.74 in males, 0.60–0.82 in females); tympanum and its annulus distinctly visible, separated from eye by about one-fourth to two-fifths of its diameter (ET/TD 0.27–0.39 in males, 0.29–0.39 in females); tympanum diameter smaller than eye diameter (TD/ED 0.68–0.81 in males, 0.70–0.84 in females); upper jaw with dentition; choanae small, rounded, located far anterolaterally at margins of roof of mouth; vomer teeth in two short rows, separated from each other by distance about three times length of individual row; tongue long and narrow, bilobed for about one-fifth of its length, free distally for one-third its length; median lingual process absent; vocal sac in males paired, lateral; external vocal sac aperture as a longitudinal, posterolaterally orientated slit, inferior, terminating at level of ventral edge of insertion of arms; internal vocal sac apertures rounded, situated close to corner of mouth.
Dorsal surfaces of head, trunk and limbs finely shagreened; dorsum with four or five longitudinal dermal ridges on each side; median ridge extending from interorbital region almost to vent, postpalpebral and external ridges from posterior edge of upper eyelid to insertion of leg; laterodorsal ridge extending from level of insertion of arm to groin; sacral ridge extending from about one head length anterior to vent to vent, in some specimens absent; external ridge forming anterior part of supratympanic fold; posterior part of supratympanic fold less distinct, branching off from external dorsal ridge posterior to tympanum in wide angle and extending posterolaterally to insertion of arm; infratympanic fold thick and conspicuous, almost straight-lined, extending from ventral edge of eye to level of arm insertion, meeting with supratympanic fold; ventral side of limbs and body smooth except areolate postaxial side of thigh; distinct transverse fold between arms on ventral side; ventral side of trunk and head densely covered with more or less evenly scattered small, pointed tubercles in males.
Forelimbs moderately sturdy; hand relatively small (HND/SUL 0.22–0.26 in males, 0.22–0.24 in females); tips of fingers rounded, not enlarged into disks but slightly swollen volarly; transverse dorsal skin ridge separating ultimate from other phalanges on each finger; relative length of fingers: I ≤ II < IV < III; subarticular tubercles rounded, well developed, numbering one on Fingers I and II, two on Fingers III and IV, proximal tubercles on Fingers III and IV larger and more prominent than distal ones; finger webbing absent; thenar tubercle distinct, elongated, large, two-thirds length of metacarpal of Finger I; inner palmar tubercle on proximal third of metacarpal region of Fingers II and III, oval, flat; outer palmar tubercle on proximal half of metacarpal region of Finger IV, elongated, slightly more prominent than inner palmar tubercle; one supernumerary metacarpal tubercle between palmar or thenar tubercles and proximal subarticular tubercles on Fingers I, II, and IV, two on Finger III; callous longitudinal ridges between subarticular tubercles on Fingers III and IV and between subarticular tubercles and finger tips on all fingers; nuptial pads in males covering almost entire dorsal surfaces of Fingers I and II and preaxial half of dorsal side of Finger III.
Hindlimbs sturdy, very long (LEG/SUL 1.77–2.05 in males, 1.80–2.06 in females); knee reaching to insertion of forelimbs and tibio-tarsal articulation reaching slightly more than one snout length beyond tip of snout when legs adpressed forwardly to body; tibiofibula long (TFL/SUL 0.56–0.65 in males, 0.56–0.66 in females), longer than thigh (TFL/THL 1.08–1.18 in males, 1.05–1.26 in female); heels overlapping each other considerably when knees flexed and thighs held perpendicularly to median plane; two low longitudinal ridges on plantar side of tarsus between heel and metatarsal tubercles; foot slightly shorter than or equal in length to tibiofibula (FOT/TFL 0.94–1.01 in males, 0.92–1.01 in females); relative length of toes: I < II < III < V < IV; toe tips rounded, not enlarged into disks but slightly swollen plantarly; transverse dorsal skin ridge separating ultimate from other phalanges on each toe; subarticular tubercles numbering one on Toes I and II, two on Toes III and V, and three on Toe IV; low callous ridges between subarticular tubercles, and between subarticular tubercles and toe tips; pedal webbing formula
Body moderately sturdy, widest at temporal region, slightly tapering to groin; head large (HL/SUL 0.36–0.39 in males, 0.37 in females; HW/SUL 0.32–0.35 in males, 0.32 in female), longer than wide (HL/HW 1.06–1.23 in males, 1.16 in female); snout long (SL/HL 0.50–0.52 in males, 0.50 in female), pointed in dorsal view, rounded in profile, considerably projecting beyond lower jaw, much longer than wide (SL/EE 1.30–1.53 in males, 1.56 in female); canthus rostralis distinct between eye and nostril, straight-lined; loreal region oblique, strongly concave; nostrils rounded, directed dorsolaterally; situated more or less half-way between tip of snout and eye (EN/NS 0.91–1.03 in males, 0.97 in female), separated from each other by distance subequal to or shorter than distance between eye and nostril (NN/EN 0.82–0.94 in males, 0.89 in female); eyes directed anterolaterally, moderately protruding, relatively small (ED/HL 0.27–0.32 in males, 0.28 in female), its diameter much shorter than snout (ED/SL 0.55–0.63 in males, 0.56 in female); interorbital distance subequal to or larger than upper eyelid width (IO/EW 0.97–1.24 in males, 1.19 in female) and smaller or subequal to internarial distance (IO/NN 0.80–1.06 in males, 0.78 in female); tympanum and its annulus distinctly visible, separated from eye by about two-fifths to half of its diameter (ET/TD 0.36–0.47 in males, 0.41 in female); tympanum diameter smaller than eye diameter (TD/ED 0.70–0.83 in males, 0.77 in female); upper jaw with dentition; choanae small, rounded, located far anterolaterally at margins of roof of mouth; vomer teeth in two short rows, separated from each other by distance about two and half times length of individual row; tongue long and narrow, bilobed for about one-third of its length, free distally for one-third its length; median lingual process absent; vocal sac in males paired, lateral; external vocal sac aperture as a longitudinal, posterolaterally orientated slit, semi-inferior, terminating at level of centre of insertion of arms; internal vocal sac apertures rounded, situated close to corner of mouth.
Dorsal surfaces of head, trunk and limbs finely shagreened; dorsum with four longitudinal dermal ridges on each side; median ridge extending from dorsal side of snout between nostrils almost to vent; postpalpebral ridge extending from posterior portion of upper eyelid, external ridge from level of tympanum to insertion of leg; laterodorsal ridge extending from level of tympanum to groin; external ridge forming anterior part of supratympanic fold; posterior part of supratympanic fold less distinct, branching off from external dorsal ridge posterior to tympanum in wide angle and extending posterolaterally to insertion of arm; infratympanic fold thick and conspicuous, almost straight-lined, extending from ventral edge of eye to level of arm insertion, meeting with supratympanic fold; ventral side of limbs and body smooth except areolate postaxial side of thigh; distinct transverse fold between arms on ventral side; ventral side of trunk and head densely covered with more or less evenly scattered small, pointed, very small tubercles in males.
Forelimbs moderately sturdy; hand relatively small (HND/SUL 0.22–0.24 in males, 0.21 in female); tips of fingers rounded, not enlarged into disks but slightly swollen volarly; transverse dorsal skin ridge separating ultimate from other phalanges on each finger; relative length of fingers: II = IV ≤ I < III; subarticular tubercles rounded, well developed, numbering one on Fingers I and II, two on Fingers III and IV, proximal tubercles on Fingers III and IV larger and more prominent than distal ones; finger webbing absent; thenar tubercle distinct, elongated, large, half as long as metacarpal of Finger I; inner palmar tubercle on proximal third of metacarpal of Finger III, small, roundish, flat; outer palmar tubercle on proximal third of metacarpal of Finger IV, elongated, more prominent than inner palmar tubercle; one supernumerary metacarpal on Fingers I and IV, two on Finger II, and two to four on Finger III between palmar or thenar tubercles and proximal subarticular tubercles; callous longitudinal ridges between subarticular tubercles on Fingers III and IV and between subarticular tubercles and finger tips on all fingers; nuptial pads in males covering almost entire dorsal surfaces of metacarpal and proximal phalanx of Fingers I and II and preaxial halves of dorsal sides of metacarpal and [in Rwandan specimens but not in paratype and specimens from Kivu and Burundi] proximal portion of proximal phalanx of Finger III.
Hindlimbs sturdy, very long (LEG/SUL 1.84–2.04 in males, 1.87 in female); knee reaching to insertion of forelimbs and tibio-tarsal articulation reaching slightly more than one snout length beyond tip of snout when legs adpressed forwardly to body; tibiofibula long (TFL/SUL 0.59–0.66 in males, 0.62 in female), longer than thigh (TFL/THL 1.12–1.20 in males, 1.16 in female); heels overlapping each other considerably when knees flexed and thighs held perpendicularly to median body plane; two low longitudinal ridges on plantar side of tarsus between heel and metatarsal tubercles, postaxial one less distinct than preaxial one; foot shorter than or subequal in length to tibiofibula (FOT/TFL 0.94–1.03 in males, 1.07 in female); relative length of toes: I < II < III < V < IV; toe tips rounded, not enlarged into disks but slightly swollen plantarly; transverse dorsal skin ridge separating ultimate from other phalanges on each toe; subarticular tubercles numbering one on Toes I and II, two on Toes III and V, and three on Toe IV; low callous ridges between subarticular tubercles, and between subarticular tubercles and toe tips; pedal webbing formula