Brachytarsophrys guilinensis Wu, Pan, Xiao, Chen, Yu & Wei, 2025, sp. nov.

Brachytarsophrys guilinensis sp. nov. Figs 5, 6, 7, 8, 11 Type material. Holotype • GXNU YU 000904, an adult male (Fig. 5), collected on 6 September 2024 by Guohua Yu, Yuanqiang Pan, and Wei Xiao from Wantian Township, Lingui District, Guilin City, Guangxi Zhuang Autonomous Region, China (25°31'53.54"N, 110°2'43.12"E, 289 m a. s. l; Fig. 1). Paratypes • GXNU YU 000903 and YU 000905 ‒ YU 000910, seven adult males, collected on 6 September 2024 by Guohua Yu, Yuanqiang Pan, and Wei Xiao from the type locality. Etymology. The species name guilinensis is derived from the type locality of this species, Guilin City, Guangxi Zhuang Autonomous Region, China. We suggest the English common name “ Guilin Short-legged Toad ” and the Chinese common name “ Guì Lín Duǎn Tuǐ Chán (桂林短腿蟾) ”. Diagnosis. Brachytarsophrys guilinensis sp. nov. could be distinguished from its congeners by the combination of the following morphological characters: (1) smaller body size (SVL 70.0‒ 81.9 mm in eight adult males); (2) head wider than long, head width nearly 1.5 times the length, and about half of the SVL; (3) tongue broad and round, feebly notched; (4) male with nuptial pad present on the dorsal surface of the first and second fingers; (5) hind limbs relatively short and robust, heels do not meet when legs positioned at right angle to body; (6) tibiotarsal articulation reaches the angle of mouth when the hind limbs are extended forward alongside the body; (7) absence of outer metatarsal tubercle, inner metatarsal tubercle oval and approximately equal to first toe; (8) fingers without webbing, toes have webbing but incomplete, webbing formula: I 1 - 2 II 1 - 2 III 1 ½ - 3 - IV 3 - - 1 ½ V; (9) lateral fringes on toes wide; (10) several warts on the outer side of the upper eyelid, with one being relatively larger. Description of holotype. Adult male; body robust, SVL 74.6 mm; head enormous, extremely wide and flat, about 1.5 times as broad as long, and nearly one-half as broad as the SVL; snout short, rounded in dorsal view, slightly protruding beyond margin of lower jaw in ventral view, sloping in profile; canthus rostralis distinct; loreal region sloping, slightly concave; nostrils oval, much closer to eye than to snout tip; interorbital distance (11.0 mm) significantly wider than the width of upper eyelid, and wider than internasal distance (7.4 mm); occipital region slightly uplifted, forming two oval bulges and a longitudinal concave groove along the middle line across occiput; a distinct transverse groove behind the head; pupil oval, vertical; tympanum hidden; choanae large, circular, partly concealed by the maxillary shelves; vomerine teeth present in two series, touching inner front edges of choanae, separated by distance larger than length of each series; tongue broad and round, feebly notched posteriorly; an internal single subgular vocal sac with a vocal sac opening at each corner of mouth. Forelimbs short and robust; relative length of fingers I = II <IV <III; tips of fingers round, feebly dilated; no lateral fringes and webbing between fingers; nuptial pad on dorsal surface of the first and second fingers; inner metacarpal tubercle large, oval; outer metacarpal tubercle inconspicuous (Fig. 6 A). Hindlimbs relatively short and robust; heels do not meet when legs positioned at right angle to body; tibiotarsal articulation reaching angle of mouth when hind limbs are extended forward alongside the body; tips of toes round, moderately dilated; relative length of toes I <II <V <III <IV; toes have webbing but incomplete, webbing formula: I 1 - 2 II 1 - 2 III 1 ½ - 3 - IV 3 - - 1 ½ V; lateral fringes on toes wide; subarticular tubercle absent; inner metatarsal tubercle distinct, oval, approximately equal to first toe; outer metatarsal tubercle absent (Fig. 6 B). Dorsal and lateral skin rough, covered with some slightly larger black glandular warts and small granules (Fig. 6 C); several warts on the outer side of the upper eyelid, with one being relatively larger; ventral skin smooth, with some white granules scattered on abdomen and ventral sides of the limbs; pectoral glands distinct, light yellow, with one on each side near axilla; femoral glands smaller than pectoral glands, white, with one on each side of rear of thigh. Coloration of holotype in life. Iris red; dorsal surface yellow-brown, scattered with yellow patches (Fig. 5 A); black stripe between eyes, patch to back of stripe black; tympanic region brown; dorsal glandular warts black; limbs dorsal sides with multiple black stripes; ventral surface dark brown, scattered with yellow patches and white granules; ventral sides of limbs with white granules; pectoral gland light yellow; femoral gland white. Coloration of holotype in preservative. Dorsal skin dark grey, scattered with grey-white patches; interocular stripe black, patch to back of stripe black; limbs dorsal stripes black (Fig. 5 B); ventral patches grey-white; abdomen and limbs ventral granules white; pectoral gland white (Fig. 5 C); femoral gland white. Sexual dimorphism. Adult males have a nuptial pad on the dorsal surface of the first and second fingers. Additionally, males have an internal single subgular vocal sac with a vocal sac opening at each corner of the mouth. Variation. Coloration of three paratypes (GXNU YU 000906, GXNU YU 000908, and GXNU YU 000909) is similar to holotype, paratype GXNU YU 000907 has a lighter coloration, three paratypes (GXNU YU 000903, GXNU YU 000905, and GXNU YU 000910) have a brown coloration (Fig. 7). Most paratypes share same characteristic as the holotype, having a broad black stripe between the eyes, whereas GXNU YU 000903 and GXNU YU 000910 lack this stripe (Fig. 7). The femoral glands are distinct in the holotype and most paratypes, but they are indistinct in GXNU YU 000906 (Fig. 8). Advertisement call. The call description is based on recording of an individual calling in a stream, with the ambient air temperature at 20 ° C. Each call consisted of 9 to 18 (mean 13.5 ± 6.4; n = 2) notes, with a dominant frequency of 1507‒1550 Hz (mean 1528.5 ± 30.4; n = 2). Call duration was 3856.5‒7895.7 ms (mean 5876.1 ± 2856.2; n = 2). Call interval was 72.7s. Each note had a duration of 164.9–224.9 ms (mean 199.7 ± 17.2; n = 27), and the intervals between notes were 183.3–439.9 ms (mean 254.4 ± 59.6; n = 25). Distinct amplitude variations within each note showed an overall trend of increasing and then decreasing in intensity (Fig. 9). Distribution and ecology. The new species is currently only known from Wantian Township, Lingui District, Guilin City, Guangxi Zhuang Autonomous Region, China. The species inhabits a stream within a subtropical evergreen broad-leaved forest. The water in the stream is shallow (Fig. 10). During early September, male individuals were discovered on or beneath rocks (Fig. 11), and advertisement calls were heard, indicating that the new species is in breeding season. Comparisons. The new species can be distinguished from Brachytarsophrys popei by the shallow notching at the posterior end of the tongue (vs. deep notching), distinct canthus rostralis (vs. indistinct canthus rostralis), iris red (vs. iris brownish), head width about 1.5 times head length (vs. head width about 1.2 times head length), first finger equal in length to second (vs. first finger longer than second), inner metatarsal tubercle approximately equal to first toe (vs. inner metatarsal tubercle longer than first toe), and webbing formula I 1 - 2 II 1 - 2 III 1 ½ - 3 - IV 3 - - 1 ½ V (vs. I 1 ½ - 2 II 1 ½ - 3 III 2 ½ - 3 ⅔ IV 3 ⅔ - 2 V) (Zhao et al. 2014; Li et al. 2020). Furthermore, the PCA analysis suggested that the new species also differs from B. popei by a series of morphometric characters associated with head and limbs, such as shorter and narrower head, smaller eye diameter, shorter snout length, forearm length, and foot length. The new species can be distinguished from Brachytarsophrys orientalis by distinct canthus rostralis (vs. indistinct canthus rostralis), iris red (vs. iris brownish), head width about 1.5 times head length (vs. head width about 1.2 times head length), first finger equal in length to second (vs. first finger longer than second), and webbing formula I 1 - 2 II 1 - 2 III 1 ½ - 3 - IV 3 - - 1 ½ V (vs. I 1 ½ - 2 II 1 ½ - 3 III 2 ½ - 4 IV 4 - 2 V) (Li et al. 2020). Brachytarsophrys guilinensis sp. nov. can be distinguished from other known congeners by the following characteristics: smaller body size, SVL of adult males 70‒80 mm (vs. SVL of adult males 80‒90 mm in B. wenshanensis and SVL of adult males> 90 mm in B. carinense, B. intermedia, B. chuannanensis, B. feae, and B. platyparietus) (Boulenger 1889; Smith 1921; Taylor 1962; Rao and Yang 1997; Fei and Ye 2001; Fei et al. 2009; Li et al. 2020, 2022; He et al. 2024); head width about 1.5 times head length (vs. head width about 1.7 times head length in B. qiannanensis and head width about 1.2 times head length in B. platyparietus and B. wenshanensis) (Rao and Yang 1997; Fei et al. 2009; Li et al. 2020, 2022; He et al. 2024); male with nuptial pad on dorsal surface of the first and second fingers (vs. male with nuptial pad on dorsal surface of the first finger in B. qiannanensis, and male lacking nuptial pad in B. wenshanensis) (Li et al. 2022; He et al. 2024); tibiotarsal articulation reaching angle of mouth when hind limbs are extended forward alongside the body (vs. only reaching behind angle of the mouth in B. feae) (Boulenger 1887; Fei et al. 2009; Li et al. 2020); inner metatarsal tubercle approximately equal to first toe (vs. inner metatarsal tubercle longer than first toe in B. feae) (Boulenger 1887; Fei et al. 2009; Li et al. 2020); lateral fringes on toes wide (vs. lateral fringes on toes narrow in B. wenshanensis) (He et al. 2024). Moreover, the new species can be distinguished from B. chuannanensis, B. feae, B. platyparietus, B. qiannanensis, and B. wenshanensis by webbing formula I 1 - 2 II 1 - 2 III 1 ½ -