Sarax yunnan

Biology. All specimens were collected from the crevices of large rocks in the dry stream channel (Fig. 1 A). One female was observed carrying ca. 10 – 15 juveniles on its opisthosoma during the survey in October 2024 (Fig. 1 B).

Description. Male (Holotype; Figs 3 A – B, E – G, J – O, 5 A – B, G, I – J, 6 A, C, 7 A – C, G – H, 8 A, 9 A, C). Carapace. Carapace flat, much wider than long, areas between ocular triads and sulci have dense small granules (Fig. 3 A). Six anterior setae, frontal process triangular (Fig. 3 O). All eyes and median ocular tubercle (MOT) well developed, MOT bristleless; lateral ocular triad (LOT) pale, slightly separated from carapace margin, LOT and nearby area bristleless, without curved carina between ocular triads and carapace margin, lateral ocular triad well separated from carapace margin (Fig. 3 O). Sternum. All sternites (tritosternum, tetrasternum and pentasternum) sclerotized and bearing setae. Tritosternum elongated and oriented anteriorly, with its apex extending beyond base of pedipalpal coxae. Tetrasternum relatively short and small, with two pairs of setae on top area and some smaller setae sparsely near base; pentasternum shortest, with two pairs of setae, setae of posterior pair obviously smaller (Fig. 3 L). Opisthosoma. Ventral sclerites slightly lighter than other area of opisthosoma (Fig. 3 B). Ventral sacs and ventral sac covers well developed (Figs 9 A, C). Gonopod. As wide as long, widest at distal third (Fig. 7 A); LoL 2 digitiform, tilted 45 ° towards the axis (Figs 7 B, C); LaM not obvious; LoD short, basal part weakly sclerotized, with sparse denticles (Figs 7 C, H); PI long and triangular, tapering from broad base to sharp apex, with sparse denticles at base (Figs 7 B, G); fistula with sparse ventral denticles, ventral side sclerotized, gradually transitioning to membranous as turns towards dorsal side (Figs 7 A – C, G – H). Chelicera. Basal segment with four retromarginal teeth, proximal one largest, distal one bifid; with one short promarginal projection. Claw with 5 – 6 denticles, retrolateral and prolateral surfaces of claw with row of setae basally to medially, respectively. Bifid tooth on basal segment with dorsal cusp larger than ventral cusp, tip of dorsal cusp further bifid (Figs 3 K, 5 J). Pedipalp. Obviously longer than those in females. Inner margin of coxae bears short and dense setae, extending to semicircular carina. Coxa with many setae on the ventral surface. Trochanter with many rufous setae on antero-dorsal side. One ventral spine, ventral apophysis large and prominently pointed (Figs 6 A, C). Femur with three dorsal spines (Figs 3 E, 5 B) and four ventral spines (Figs 3 G, 5 A); one prominent setiferous tubercle between dorsal spine III and proximal margin; one short spine between ventral spine III and proximal margin, two-thirds length of spine III. Patella with four dorsal spines in primary series, prominent setiferous tubercle distal to spine I (Figs 3 E, 5 B); three ventral spines, two setiferous tubercles between spine I and distal margin (Figs 3 G, 5 A). Tibia with two spines on the dorsal and ventral side, respectively; one setiferous tubercle near the base of proximal ventral spine. Tarsus with two subequal small nail-like dorsal spines; cleaning organ with 27 – 30 setae in ventral row (Fig. 3 F). Legs. Reddish-brown, with slightly darkened indistinct wide annuli. Tibia of leg I with 30 articles. Tarsus I with 46 articles, proximal articles slightly longer than subsequent articles (Fig. 8 A). Basitibia IV divided into four pseudo-articles. All walking legs with pulvilli (Figs 3 J, M, 5 G). Trichobothria of distitibia IV (Figs 3 N, 5 I): sc and sf series each with six and four trichobothria; bt situated medially on dorsal part of basal pseudo-article, bc relatively close to stf; distances between bf, sbf and stf subequal, stf located at ca. 2 / 3 position from proximal to distal end of distitibia IV; the arrangement of tf, tm, and tc constitutes a triangular configuration, a pattern frequently encountered in whip spiders. Measurement. see Table 4. Female (paratype, MHBU-AMB- 2024 - 1004) (Figs 3 C – D, H – I, 5 C – D, 9 B, D, F, H). Body features mostly like those in males. Genitalia. Genital operculum with triangular extensions (TEG, Fig. 9 D). Gonopod almost conical, like finger, distal opening large and obvious, tilted ca. 45 ° towards the axis (Figs 9 F, H). Pedipalp. Obviously shorter than in males (Figs 3 H – I, 5 C – D). Femur with three dorsal spines, four ventral spines, proximal second spine longest. Patella with four dorsal spines, three ventral spines; distal 2 / 3 of ventral side with four setiferous tubercles. Tibia with two large dorsal spines, basal part of each spine with many rufous setae; with two ventral spines, distal one longer. Tarsus is like the male. Measurement. see Table 4. Variability. Distal one (in holotype) or two (in MHBU-AMB- 2024 - 1002) teeth of cheliceral basal segment bifid distally. Count of articles of tibia I ranging from 25 to 30 (n = 3); count of articles of tarsus I ranging from 37 to 46 (n = 3). Distitibia IV with (MHBU-AMB- 2024 - 1003) or without (other specimens) nbc next to the bc. For detailed variation of measurements, see Table 4.

Figures 1, 3, 5 A – D, G, I – J, 6 A, C, 7 A – C, G – H, 8 A, 9 A – D, F – H. Chinese name: 云南aeDze

Diagnosis. Sarax yunnan sp. nov. can be distinguished from S. seychellarum by the presence of ventral sacs (vs. absent in S. seychellarum, see Miranda et al. 2021 b: 228), the presence of 25 to 30 articles in tibia of leg I (vs. 21 in S. seychellarum), the presence of 37 to 46 articles on tarsus I (vs. 37 in S. seychellarum), and the presence of five to six cheliceral claw teeth (vs. eight in S. seychellarum). S. yunnan sp. nov. can be distinguished from S. sinensis by the presence of five to six teeth on mesal part of cheliceral claw (vs. eight in S. sinensis), the distinct ventral sac covers (VSC) (vs. VSC are not obvious in S. sinensis) (Figs 9 A – E), the presence of three large dorsal spines on pedipalp femur (vs. four in S. sinensis), the presence of 25 to 30 articles in leg I tibia (vs. 20 to 21 in S. sinensis), the presence of 37 to 46 articles on tarsus I (vs. 35 in S. sinensis) (Fig. 8), and the presence of four pseudo-articles on basitibia IV (vs. three in S. sinensis).

Distribution. Known only from the type locality (Fig. 10).

Etymology. The specific epithet is derived from the type locality; noun in apposition.

Type material. Holotype ♂ (MHBU-AMB- 2024 - 1001), CHINA: Yunnan Province, Yingjiang County, Nabang Township, 7 – 11 October 2024, leg. K. Yu, Y. Ni and Y. Xu. Paratypes. 2 ♂ 7 ♀ 2 j (MHBU-AMB- 2024 - 1002 ~ 1012), same data as holotype.