Distribution of Odontobatrachus spp. in the western Upper Guinea forest zone (country code: GN = Guinea, SL = Sierra Leone, LR = Liberia, CI = Côte d’Ivoire). The map shows forest cover (Arino et al. 2012; green shading) and elevation (increasing from light to dark grey). The arrow indicates the restricted type locality of O. natator. Colour code reads as follows: blue = O. natator, red = O. ziama sp. n., yellow = O. smithi sp. n., green = O. fouta sp. n., orange = O. arndti sp. n.

Scatter plot of the first and second axis of the principal component analyses for absolute values of morphological measurements in males (a) and females (c), and respective ratios in males (b) and females (d). For PCA loadings see Tables 3 and 4. Lines are drawn to indicate the centroid of points for each species. For colour code see Fig. 1.

Male syntype of Odontobatrachus natator (BMNH 1947.2.30.68) in ventral and dorsal view (top from left to right, scale bar: 10 mm); head in lateral view, details of pedal webbing, details of hand (bottom left to right, scale bar: 5 mm).

Odontobatrachus natator in life: a) female ZMB 78303, Ziama Forest, Guinea; b) male ZMB 78214, N’Zérékoré Region, Guinea; c) Gola Rainforest National Park, Sierra Leone; d) Freetown Area (type locality of Petropedetes natator Boulenger, 1905), Sierra Leone; e) ZMB 80504, Nimba County, Liberia; f) colouration of male femoral glands hardly visible (male shown in d); g) colouration distinctly contrasted against the femur (male shown in e).

Male holotype of Odontobatrachus ziama sp. n. (ZMB 78300) in ventral and dorsal view (top from left to right, scale bar: 10 mm); head in lateral view, details of pedal webbing, details of hand (bottom left to right, scale bar: 5 mm).

Odontobatrachus ziama sp. n. in life: a) female paratype ZFMK 95465 Ziama Forest, Guinea; b) female paratype MHNG 2731.46, from Ziama Forest, Guinea; c) female ZMB 78267, Kankan Region, Guinea; d) female ZMB 78263, Kankan Region, Guinea; e) ventral view of ZFMK 95465; f) colouration of femoral glands in male ZMB 78269. Mind the variation in shape of snout in lateral view from rounded (b) to pointed (d) and the variation in shape of dorsal ridges ranging from sub-elliptical (a, b), elongated (c) to conic (d).

Male holotype of Odontobatrachus smithi sp. n. (ZMB 78310) in ventral and dorsal view (top from left to right, scale bar: 10 mm); head in lateral view, details of pedal webbing, details of hand (bottom left to right, scale bar: 5 mm).

Odontobatrachus smithi sp. n. in life: a) male ZMB 78307, Kindia Region, Guinea; b) female paratype MHNG 2731.47, Fouta Djallon: Pita, Hörè Binti, Guinea); c) colouration of femoral glands in ZMB 78307; d) ventral view of female paratype MHNG 2731.47.

Male holotype of Odontobatrachus fouta sp. n. (ZMB 78314) in ventral and dorsal view (top from left to right, scale bar: 10 mm); head in lateral view, details of pedal webbing, details of hand (bottom left to right, scale bar: 5 mm).

Odontobatrachus fouta sp. n. in life: a) female paratype ZMB 78315, Fouta Djallon: Labé, Sala, Guinea; b) male holotype ZMB 78314, Fouta Djallon: Labé, Sala, Guinea; c) male Dalaba\Chute de Ditinn, Guinea; d) colouration of femoral glands in the male holotype ZMB 78314.

Male holotype of Odontobatrachus arndti sp. n. (ZMB 78355) in ventral and dorsal view (top from left to right, scale bar: 10 mm); head in lateral view, details of pedal webbing, details of hand (bottom left to right, scale bar: 5 mm).

Odontobatrachus arndti sp. n. in life: a) and c) Nimba Mts, Guinea; b) Mt. Sangbé, Côte d’Ivoire. Non vouchered specimens. Note parasitic mites (minuscule red dots) close to the cloaca in (c).

Spectrogram and oscillogram of two calls of Odontobatrachus arndti sp. n. from Nimba Mts., Guinea with a dominant frequency of app. 2800-3400 Hz, a fundamental frequency of app. 1400-1700 Hz and 22 notes showing decreasing pause duration between notes (a) and 5 notes with constant pauses between notes (b).