Buresilia gumushanensis sp. nov.

(Figs. 1–7)

Type Material: Holotype: 1 ♂, TÜRKİYE, GümüŞhane Province, Tersun Mountain (40°18’0.6”N, 39°18’22”E), asl 1976 m, 19.VII.2022 – 16.X.2022, leg. K.Kurt & E. A. Yağmur. Paratypes. 3 ♂, same data as holotype.

Diagnosis: Eye mound trapezoid shaped, with 10–11 black-tipped denticles (Fig. 1). Legs I and III with slightly thicker, femur covered with microdenticles and setae (Fig. 4b). Pedipalp femur basally with conical apophysis, ventrally with setae, dorsally with setae and a few denticles, patella with dorsomedial apophysis and tibia with prolateral apophysis (Figs. 2, 3). Chelicera basal segment dorsally with denticles and setae, second segment with setae (Fig. 4a). Truncus penis basally widened triangular-shaped (Fig. 5). The differences between the newly described species and the other species of the genus Buresilia are given in the section on morphological remarks.

Etymology: The specific epithet is derived from the name of GümüŞhane Province in Turkey, where the type materials were collected, and the Latin suffix “- ensis ”.

Description: male (holotype). Body (Fig. 1): Habitus as presented in Fig. 1. Body nearly rectangular in dorsal view, length 3.2 mm, width 2.1 mm. Body dorsally not distinctly saddle-marked. In front of eye mound with 10–12 black denticles, posterior side with transverse rows of black denticles. Ozopores with 1–2 black denticles. Supracheliceral lamellae smooth, with two black-tipped spurs. Abdomen dorsally not distinctly saddle marked, with transverse rows of dark brown spots and irregularly spaced microdenticles and black setae.

Eye mound (Fig. 1): prominent (length 0.6 mm, width 0.6 mm, height 0.45) and located high, trapezoid shaped, with 10–11 black-tipped denticles in two rows.

Ventral side: Coxae ventrally, genital operculum and opisthosomal sternites with setae.

Chelicerae (Fig. 4a): Not enlarged. Basal segment dorsally with 6–8 black-tipped denticles and setae. Second segment of chelicerae with brown zebra-stripped pattern, with setae. Length of basal segment: 0.7 mm, second segment 1.19 mm.

Pedipalps (Figs. 2, 3): Femur basally with conical apophysis, ventro-basally with dense setae, dorsally covered with setae and a few denticles. Femur with a distomedial hump covered with setae. Patella dorsally and ventrally with setae, dorsomedially with finger-shaped apophysis covered with only setae. Tibia with prolateral apophysis covered with setae. Tarsus with setae and ventral microdenticles. Claw smooth. Length of pedipalp segments: femur 1.2, patella 0.6, tibia 0.7, tarsus 1.4; total length 3.9 mm.

Legs (Fig. 4b): Legs I and III slightly thicker. Femur covered with microdenticles and setae. Patella with black setae; distal margins of the patella covered with 2–3 denticles. Tibia dorsally with setae, ventrally with rows of black denticles and setae. Metatarsi with hairs; Tarsus only with bristle. Length of legs (in mm): I: 16.5 (fe: 3.24), II: 29.5 (fe: 6.0), III: 15.2 (fe: 3.51), IV:27 (fe: 5.3).

Genital morphology (Fig. 5): Truncus of penis basally very expanded, narrowed in middle and then roughly parallel sides to the glans penis. Glans penis stocky, ventrally enlarged, bag-shaped and dorsal not flat, slightly collapsed. Glans penis dorsally with one seta, ventrally with two setae. Stylus long. Truncus length: 1.70 mm; glans length: 0.4 mm.

Female: Unknown.

Colouration in ethanol: Prosoma with yellowish brown and dark brown patches. Abdominal tergites with yellowish brown and brown spots. Coxae dark brown, abdomen ventrally and genital operculum light yellowishgrey. Pedipalps: femur, patella and tibia dark brown, distal end of tarsus light yellowish brown. Chelicerae light to dark brown. Legs: femur dark brown, other parts of the leg light brown.

Morphological remarks. The new species is distinguished from the other three species of the genus Buresilia by the following characters: 1) Legs I: slightly thicker and covered with microdenticles and setae (extremely thickened and dense denticles in B. macrina; thickened and densely with microdenticules in B. nigerrima; slightly thickened and sparse with microdenticles in B. kibrisensis). 2) Chelicerae: basal segment dorsally covered with denticles and setae, distal segment only with setae (basal segment dorsally covered with densely denticles, distal segment apically with 8–10 microdenticles in B. macrina; basal segment dorsally with sparse denticles, distal segment apically with 1–2 microdenticle in B. nigerrima, basal segment dorsally with sparse denticles, distal segment only with setae B. kibrisensis. 3) Pedipalps: femur ventrally with dense setae, dorsally with setae and a few denticles (femur ventrally setae, dorsally with dense denticles; patella dorsally several denticles in B. macrina); femur ventrally setae, patella dorsally without denticles in B. nigerrima; femur ventrally setae, patella dorsally without denticles in B. kibrisensis. 4) Truncus penis: basally widened triangular-shaped (basally narrow triangular-shaped in B. macrina; basally nearly oval-shaped in B. nigerrima; rectangular-shaped in B. kibrisensis).

Molecular analysis. A total of 647 base pairs of COI genes were obtained for Buresilia gumushanensis sp. n. The Bayesian analysis generated a phylogenetic tree with high Bayesian posterior probabilities (BPP) values. The COI gene-based Bayesian tree topology indicates that the new species is on a different branch from other species in the Phalangiidae family, which is supported by the high BPP values (Fig. 6). In this study, the Kimura 2-parameter (K2P) method (Kimura 1980), which is the standard in DNA barcoding, was used to calculate the genetic distance between species (Tong et al. 2023). The K2P genetic distance indicates that Buresilia gumushanensis sp. nov. differs by 14–21% from similar species in the Phalangiidae family (Table 2).

Buresilia gumushanensis sp. nov. is morphologically distinct from other members of the genus. Additionally, the analysis performed on the entire COI gene region revealed high (BPP) and (K2P) values, indicating that the new species is located in a separate branch of the phylogenetic tree and is a new taxon, distinct from other Phalangiidae species.

Ecological data (Fig. 7): The type locality of the newly described species, Tersun Mountain, is characterised by a forest comprising Abies sp. species in the northern parts and Pinus sylvestris in the southern parts. Samples were collected from tree trunks and beneath the bark in areas with high moisture content and humidity.