Eusimonia dentapicalis Fan, Zhang & Zhang, 2024, sp. nov.
Creators: name: Fan, Wenlong
name: Zhang, Chao
name: Zhang, Feng
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Solifugae
Karschiidae
Eusimonia
Eusimonia dentapicalis

description: Eusimonia dentapicalis sp. nov.
Figures 1, 8–11, 16H, I, 17B. Table 1, 2.
Type Material. Holotype ♂ (MHBU-Sol-GS2023070401), CHINA: Gansu Province, Jinta County, Jinta Town, 39.7921°N, 99.0911°E, ca 1280m elev., 4.VII.2023, leg. Wenlong Fan.
Paratypes: 7♀♀ (MHBU-Sol-GS2023070402–09), same data as holotype; 1♂ 1♀ (MHBU-Sol-GS2023050701– 02), 1♂ 2♀ (SWUC-Sol-GS2023050701–03), CHINA: Gansu Province, Linze County, Pingchuan Town, Tangwan Village, 39.4500°N, 100.2667°E, ca 1240m elev., 7.Ⅴ.2023, leg. Jiliang Liu; 1♂ 2♀♀ (MHBU-Sol-GS2023060801– 03), CHINA: Gansu Province, Linze County, Dongxiaokouzi, 39.4000°N, 100.1833°E, ca 1320 m elev., 8.VI.2023, leg. Jiliang Liu; 2♀♀ (SWUC-Sol-GS2023030701–02), Gansu Province, Linze County, Pingchuan Town, 39.4019°N, 100.1215°E, ca 1350m elev., 3.VII.2023, leg. Wenlong Fan.
Other material. 5 juveniles (MHBU-Sol-GS2023070410-15), CHINA: Gansu Province, Jinta County, Jinta Town, 39.7921°N, 99.0911°E, ca 1280m elev., 4.VII.2023, leg. Wenlong Fan; 4 juveniles (MHBU-SolGS2023060804–07), CHINA: Gansu Province, Linze County, Dongxiaokouzi, 39.4000°N, 100.1833°E, ca 1320 m elev., 8.VI.2023, leg. Jiliang Liu.
Etymology. The specific name is derived from a combination of the Latin words “ apical ” and “ dentata ”, meaning terminal tooth, referring to the presence of subterminal (MST) teeth on cheliceral fixed finger.
Diagnosis. Males of Eusimonia dentapicalis sp. nov. differ from other Eusimonia species except E. turkestana by having a triangular-shaped dorsal secondary flagellum (Figs 9C, 17B) and the absence of spines on pedipalpal tarsus (Figs 16H, I). E. dentapicalis sp. nov. differs from E. turkestana by the dorsal secondary flagellum overall shape wider and the tubelike ventral primary flagellum blunt at the apex (Figs 9C, 17B), by having weaker spiniform setae on the anterior edge of the propeltidium (Fig. 9D), by a shorter, curved hornlike process (extending not further than the FSD tooth, where it extends nearly to the FD in E. turkestana) and the absence of tooth on hornlike process (Fig. 9C); by the presence of 4–5 tiny subterminal (FST) teeth on fixed finger mucron in all males examined (Fig. 9C), and by the longer ctenidia on sternite III than E. turkestana (ctenidia in E. dentapicalis extend past the distal border of the sternite III, but ctenidia in E. turkestana not extend past) (Figs 9E, 11E). Females differ from other Eusimonia species by the presence of tiny FST on the cheliceral fixed finger, the (Figs 10A, 11G), genital operculum triangular in shape with clear demarcation between the plates, genital operculum distally widened and genital opening visible between plates (Fig 10E, 11I).
Description. Male. Holotype (MHBU-Sol-GS2023070401).
Measurements. Total body length 13.21, CH 1.22, CL 4.74, CW 1.13, PL 1.92, PW 2.86, A/CP 6.01, CL/ CH 3.87. Pedipalp 13.38 (3.19, 3.45, 3.28, 1.21), leg Ⅰ 10.19 (2.05, 2.73, 1.89, 0.82, 0.05), leg II 9.92 (1.80, 2.67, 1.22, 0.84, 0.84), leg III 11.85 (2.40, 3.18, 1.50, 0.68, 0.73), leg IV 16.42 (3.43, 3.19, 3.73, 0.63, 1.04).
Coloration. In 75% ethanol-preserved specimens (Figs 8A, B). Prosoma general background yellow, and opisthosoma’s general background yellow-green. Propeltidium yellow with brown on either side of ocular tubercle, densely covered with short yellowish-brown setae and sparsely with long tawny setae; ocular tubercle black (Fig. 9D). Opisthosoma densely covered with yellowish-brown setae dorsally, abdominal tergites and sclerites dark yellow-green. Chelicera yellow, covered with long brownish setae; each terminal tooth of fixed finger and movable finger reddish (Figs. 9A, B), pedipalps and legs yellowish-brown except coxa and trochanter, covered with brownish setae. Malleoli white.
Propeltidium. Wider than long (Fig. 9D), with a dense pubescence of thin, short, anteriorly directed fine setae; median eyes separated by less than one diameter; propeltidium lobe without eyespot. Anterior, posterior, and lateral edges with several long, curved spiniform setae perpendicular to the surface of the propeltidium. Ocular tubercle with a row of proximal spiniform setae, four short and two long middle distal spiniform setae. On each side of ocular tubercle, propeltidium with longer spiniform setae (Fig. 9D).
Chelicerae. Fixed finger with median teeth series comprising well-developed primary teeth (FP, FM and FD), FD tooth size lesser, while FM and FP similar in size (Figs 9A–C, 11A, B); moreover, median teeth series comprising all secondary teeth (2 FSD and 2 FSM); secondary teeth overall size smaller than primary teeth, distal FSD and FSM smaller than proximal FSD and FSM (Fig. 9C). Retrofondal teeth series uninterrupted with five teeth (1 RFP, 1 RFM, 3 RFA), and profondal teeth series consisting of five teeth (2 PFSP, 1 PFP, 1 PFSM, 1 PFM) (Fig. 9C). Fixed finger asetose area sinuous, with ventral margin predominantly linear in lateral aspect; prodorsal carina not sharp, not elevated in lateral aspect (Figs 9A–C). Cheliceral fixed finger hornlike process slightly curved without teeth (Fig. 9C), mucron with four tiny subterminal (FST) teeth, and apex (FT tooth) curved, hook-shaped (Fig. 9C). Movable finger with median teeth series comprising well-developed MP and MM primary teeth, the former of which larger, and two MSM secondary tooth smaller than MM (i.e., MP> MM> MSM), movable finger one MSM teeth close to MP, another one close to MM, MSM upright and triangular-shaped; movable finger without subproximal (MSP) or subterminal (MST) teeth; movable finger mucron moderately long, with obvious prolateral flange in front of the MM tooth. Retrolateral and dorsal surfaces with abundant retrolateral manus (rlm) and retrolateral finger (rlf) setae, of different sizes,, which are predominantly straight and rigid; some of these setae arranged in bilaterally symmetrical patterns, as some principal retrolateral finger (principal rlf) setae that more flexible than others (Figs 9A, 11A); prolateral surface with array of setal types (Figs 9B, 11B), as follows: proventral distal (pvd) setae consisting of row of strong setae, starting at level of the flagellum and ending near level of PFM tooth; proventral subdistal (pvsd) setae arranged in rather disorganized pattern, pvsd comb not markedly differentiated; carpet-like field of bristle-like promedial (pm) setae broad. Stridulatory plate longer than high, occupying most of the prolateral surface of manus, above stridulatory plate two prodorsal proximal (pdp) setae existing; stridulatory apparatus not obvious. Distal limit of the prolateral setose area of movable finger reaching midpoint between MSM and MM teeth; movable finger prodorsal (mpd) setal series consisting of spinous setae arranged in a rather staggered row, adjacent to abundant non-plumose setae of the movable finger promedial (mpm) and proventral (mpv) setal series (Figs 9B, 11B). Flagellum typical of Eusimonia, bear two distinct, membranous or weakly sclerotized, sessile flagella: a broad, thin, dorsal secondary flagellum and a tubelike ventral primary flagellum (Figs 9A–C, 11A, B, 17B); flagellum without flagellar complex subspiniform to spiniform (fcs) setae; membranous dorsal flagellum (secondary flagellum) with a slight central depression (Figs 9C, 17B).
Opisthosoma. The entire surface covered with almost adpressed fine setae, and numerous long, curved, bifurcate setae, and tergites with abundant setae. Sternite III with 4+5 coarse and spiny ctenidia extend past the distal border of the sternite III (Figs 9E, 11E), sternite IV with a row of 15 long and thin peg-like ctenidia, almost reach to the distal edge of the sternite Ⅴ (Figs 9F, 11F).
Pedipalps. Entirely covered with short fine setae and long, thick setae. Tarsus without spines; posterior half of metatarsus thickens inward, resembling a hump, with six quite strong, distally diminishing, forward-inclined spines which thicker and flattened at distal ends (Figs 11C, D, 16H, I).
Legs. Covered with abundant short and a few long setae, similar to those on pedipalps. Leg I with two small claws but without spine-like setae. Tibiae II, III, and IV with a pair of distal spine-like setae ventrally; tibiae II and III with a single dorsal spine-like setae. Metatarsi II and III with a series of three dorsal spine-like setae, a pair of distal spine-like setae ventrally, and some paired short, thick, spine-shaped bristles over their entire ventral surface; metatarsus IV also with these paired bristles over its entire ventral surface and two distal spine-like setae ventrally.
Female. Paratype female (MHBU-Sol-GS2023070402).
Measurements. Total body length 12.72, CH 1.35, CL 4.30, CW 1.10, PL 1.89, PW 2.50, A/CP 4.07, CL/ CH 3.20. Pedipalp 11.13 (3.00, 2.76, 2.78, 1.00), leg Ⅰ 7.08 (1.37, 1.76, 1.49, 0.61, 0.04), leg II 7.95 (1.39, 1.29, 2.10, 0.66, 0.58), leg III 10.95 (2.03, 2.75, 2.24, 0.74, 0.66), leg IV 14.84 (3.11, 3.26, 3.03, 0.81, 0.77).
Coloration. In 95% ethanol-preserved specimens (Figs 8C, D). Coloration as in the male.
Propeltidium. Mostly the same as male, but female ocular tubercle spiniform setae on each side of ocular tubercle not as strong as in male (Fig. 10D).
Chelicera. Fixed finger with median teeth series comprising well-developed primary teeth (FP, FM and FD), FD tooth size smaller, while FM and FP similar in size (Figs 10A–C, 11G, H); moreover, median teeth series comprising all secondary teeth (2FSD and 2 FSM); secondary teeth overall size smaller than primary teeth, distal FSD and FSM smaller than proximal FSD and FSM. Retrofondal teeth series uninterrupted with seven teeth (3RFSP, 1RFP, 1RFM, 2RFA); profondal teeth series consisting of three teeth (1PFP, 1PFSM, 1PFM) (Fig. 10C). Fondal teeth graded as II, IV, III, V, I, VI, VII retrolaterally; I, II, III prolaterally (Fig. 10C). Fixed finger mucron with two tiny subterminal (FST) teeth. Movable finger with median teeth series comprising well-developed MP and MM primary teeth, the former of which larger, and four MSM, four MST and three MSP secondary teeth that smaller than MM (i.e., MP> MM> MSM> MSP> MST), movable finger MSM teeth located MM and MP center, MST teeth located MM front, and MSP located MP after; all secondary teeth upright and triangular-shaped (Figs 10A, B, 11G, H). Cheliceral setose areas and stridulatory plate mostly like male, but female proventral distal (pvd) setae only consist of row of plumose setae (Figs 10B, 11H).
Opisthosoma. The entire surface covered with almost adpressed fine setae and numerous long, curved, bifurcate setae. Genital operculum with clear demarcation between the plates, distal border widened, resembling a triangle shape. Genital opening visible between plates. (Figs 10E, 11I). 14 short needle-like ctenidia on sternite IV extending 3/4 the length of the following sternite (Figs 10F, 11J).
Pedipalps. Entirely covered with short fine setae and long, thick setae and without spines.
Legs. Same as in the male.
Distribution and habitat. E. dentapicalis sp. nov. is known from the northwest part of Gansu Province, China (Fig. 1). Habitat: desert (Figs 2C–E). E. dentapicalis sp. nov. also live in clayey, stony or sandy loam deserts at low altitudes.
Collection method. During the night using an ultra-violet lamp. Under ultraviolet light, Solifugae reflect a faint blue glow, making it easy to spot and catch. Given their nocturnal habits, we also collect specimens using pitfall traps.
Variability. Males. Total length 11.32–16.64. Body coloration light yellow to yellow. Chelicerae with manus yellowish to brown. The number of cheliceral fixed finger fondal teeth 9–11 (profondal teeth 4–5; retrofondal teeth 5–6), FST 4–5. The number of ctenidia on sternite IV 12–15. Females. Total length 12.32–15.39. Variability of body coloration as in males. The number of cheliceral fixed finger fondal teeth 10–11 (profondal teeth 3–5; retrofondal teeth 6–7). FST 2–4, MST 4–5, MSP 3–4. The number of ctenidia on sternite IV 13–15.
Remark. Based on the comparison of genetic distances, with a genetic distance of 0.15% (Table 2) between male and female collected from same locations, we believe that they are same species.
description: Published as part of Fan, Wenlong, Zhang, Chao & Zhang, Feng, 2024, First report of the family Karschiidae (Arachnida, Solifugae) from Gansu Province, China, with description of two new species, pp. 369-394 in Zootaxa 5492 (3) on pages 379-385, DOI: 10.11646/zootaxa.5492.3.5, http://zenodo.org/record/13234925