Lagynochthonius sanhuaensis, Sun & Guo & Zhang, 2024

Sun, Jianzhou, Guo, Xiangbo & Zhang, Feng, 2024, Five new epigean Lagynochthonius species (Pseudoscorpiones, Chthoniidae) from southern China, ZooKeys 1198, pp. 101-134 : 101

Lagynochthonius sanhuaensis sp. nov.

Figs 18 , 19 , 20 , 21 Chinese name: 三花拉伪蝎

Type material.

Holotype ♂ (Ps.-MHBU-GZ2022070201): China, Guizhou Province, Tongren City, Yinjiang County, 500 m near Sanhua Mountain, under topsoil and in the leaf litter layer [27°53′40.73″N, 108°32′46.16″E], 818 m a.s.l., 7 July 2022, Yanmeng Hou, Lu Zhang, Nana Zhan, Jianzhou Sun & Long Lin leg. Paratypes: 2 ♂ (Ps.-MHBU-GZ2022070203 & GZ2022070205) and 2 ♀ (Ps.-MHBU-GZ2022070202 & GZ2022070204), all with the same data as the holotype.

Etymology.

Named after the Sanhua Mountain, near the type locality. A noun in apposition.

Diagnosis.

(♂♀). Moderately sized epigean species; carapace with four eyes, anterior margin smooth and epistome hump-shaped; tergites I-IV each with four setae. Rallum with seven blades. Pedipalps slender, chela 6.80-7.89 (♂), 5.31-5.40 (♀) × as long as broad; femur 6.50-6.63 (♂), 5.70-6.00 (♀) × as long as broad; chelal fingers without intercalary teeth, fixed chelal finger with a modified accessory tooth (td) on prolateral-retrolateral face; chemosensory setae (sc) present on dorsum of chelal hand; sensilla present.

Description.

Males (holotype and paratypes) (Figs 18A , 19A-F , 20 , 21 ).

Color generally pale yellow, chelicerae, carapace, pedipalps and tergites slightly darker.

Cephalothorax (Figs 19D , 20A ): carapace nearly subquadrate, 0.92-0.97 × as long as broad, weakly constricted basally; posterior region with squamous sculpturing laterally, other area smooth, without furrows; anterior margin smooth, without serrate; epistome small and hump-shaped; four eyes, anterior pair of eyes well-developed, posterior pair with flat lenses; with 18 setae arranged s4s: 4: 4: 2: 2, most setae heavy, long and gently curved, anterolateral setae much shorter than others; with two pairs of lyrifissures, first pair situated middle to the setae of ocular row, second pair situated lateral to the sole pair of setae of posterior row. Manducatory process with two acuminate distal setae, anterior seta less than 1/2 length of medial seta; apex of coxa I with a rounded anteromedial process; coxae II with 9-11 terminally indented coxal spines on each side, set as an oblique and arc row, central spines slightly longer than the others (Fig. 20D ); intercoxal tubercle absent; Chaetotaxy of coxae: P 3, I 3, II 4, III 5, IV 5.

Chelicera (Figs 19C , 20B ): almost as long as carapace, 1.81-1.93 × as long as broad; five setae and three lyrifissures (including an exterior condylar lyrifissure, an exterior lyrifissure and extra lyrifissure (near sub basal setae)) present on hand, all setae acuminate, ventrobasal setae shorter than others; movable finger with one medial seta. Cheliceral palm has moderate wrinkle on both ventral and dorsal sides. Both fingers well provided with teeth, fixed finger with 14-18 teeth, distal one largest; movable finger with 16-18 retrorse contiguous small teeth; galea completely vestigial (Fig. 20B ). Serrula exterior with 19-20 and serrula interior with 10-12 blades. Rallum with seven blades, the distal one longest and recumbent basally, with fine barbules and slightly set apart from the other blades, latter tightly grouped and with long pinnae, some of which are subdivided (Fig. 20C ).

Pedipalp (Figs 19A, B, E , 20E , 21A, B ): trochanter 1.88-2.14, femur 6.50-6.75, patella 2.22-2.50, chela 6.80-7.89, hand 3.20-3.67 × as long as broad; femur 2.57-2.65 × as long as patella; movable chelal finger 1.15-1.19 × as long as hand and 0.53-0.56 × as long as chela. Setae generally long and acuminate. Chelal palm gradually constricted towards fingers, apodeme complex of movable chelal finger strongly sclerotized. Fixed chelal finger and hand with eight trichobothria, movable chelal finger with four trichobothria, ib and isb situated close together, submedially on dorsum of chelal hand; eb, esb and ist at base of fixed chelal finger; esb and eb at almost the same level and ist slightly distal to esb; it slightly distal to est, situated subdistally; et slightly near to tip of fixed chelal finger, very close to chelal teeth; dx situated distal to et; sb slightly closer to st than to b; b and t situated subdistally, t situated at the same level as it and distal to b; est situated distal to b and close to it (Figs 19A , 21A ). Fixed chelal finger with sensilla af1-2 close together, near tip; movable chelal finger with four sensilla: am1-2 near tip, p2 slightly distad of sb, p1 proximad of sb and very close to chelal teeth (Fig. 21A ). Microsetae (chemosensory setae) present on dorsum of chelal hand (Figs 19B , 21B ). Both chelal fingers with a row of teeth, spaced regularly along the margin, teeth smaller distally and proximally: fixed finger with 18 or 19 well-spaced, pointed teeth, and a modified accessory tooth on prolateral-retrolateral face (td, slightly distal to dx); movable finger with six well-spaced, pointed teeth, plus 8-10 vestigial, rounded and contiguous basal teeth.

Opisthosoma: generally typical, pleural membrane finely granulated. All tergites and sternites undivided; setae uniseriate and acuminate. Tergal chaetotaxy I-XII: 4: 4: 4: 4: 4: 4-6: 4-6: 5-6: 6: 4: T2T: 0. Sternal chaetotaxy IV-XII: 10-12: 10-11: 11-13: 9-13: 10-12: 10-12: 9: -: 2. Genital region: sternite II with ten setae scattered on median area, genital opening slit-like, sternite III with 16-18 setae (Fig. 19F ).

Legs (Fig. 21C, D ): fine granulation present on anterodorsal faces of trochanter IV, femur I; scale-like texture display on anterodorsal faces of femoropatella IV. Leg I: femur 2.57-2.65 × as long as patella; tarsus 2.07-2.28 × as long as tibia. Leg IV: femoropatella 2.67-3.00 × as long as deep; tibia 4.43-5.33 × as long as deep; with basal tactile setae on both tarsal segments: basitarsus 2.50-3.50 × as long as deep (TS = 0.36-0.43), telotarsus 8.75-11.67 × as long as deep and 2.33-2.36 × as long as basitarsus (TS = 0.21-0.23). Setae of leg I (trochanter to tibia) 3-4: 7-8: 3-6: 6-9, setae of leg IV (trochanter to basitarsus) 2-3: 3-5: 5-6: 7-8: 5-7. Arolium not divided, slightly shorter than the simple claws.

Adult females (paratypes) (Figs 18B , 19G ). Mostly same as males; tergal chaetotaxy I-XII: 4: 4: 4: 4: 4-6: 6: 5-6: 6: 6: 4: T2T: 0; sternal chaetotaxy IV-XII: 12-13: 13-15: 11-13: 11-12: 12: 11: 9-10: -: 2. Genital region: sternite II with ten setae scattered on median area, sternite III with a row of 10-12 setae.

Dimensions (length/breadth or, in the case of the legs, length/depth in mm; ratios in parentheses). Males: body length 1.30-1.36. Pedipalps: trochanter 0.15/0.07-0.08 (1.88-2.14), femur 0.52-0.54/0.08 (6.50-6.63), patella 0.20-0.21/0.08-0.09 (2.22-2.50), chela 0.68-0.73/0.09-0.10 (6.80-7.89), hand 0.32-0.34/0.09-0.10 (3.20-3.67), movable chelal finger length 0.38-0.41. Chelicera 0.29-0.30/0.15-0.16 (1.81-1.93), movable finger length 0.18-0.19. Carapace 0.32-0.36/0.35-0.37 (0.91-0.97). Leg I: trochanter 0.09-0.11/0.08-0.09 (1.00-1.22), femur 0.27-0.28/0.05 (5.40-5.60), patella 0.13-0.15/0.05-0.06 (2.33-3.00), tibia 0.14-0.15/0.04-0.05 (2.80-3.75), tarsus 0.30-0.32/0.03 (10.00-10.67). Leg IV: trochanter 0.13-0.16/0.10-0.11 (1.30-1.45), femoropatella 0.46-0.48/0.16-0.18 (2.67-3.00), tibia 0.31-0.32/0.06-0.07 (4.43-5.33), basitarsus 0.14-0.15/0.04-0.06 (2.50-3.50), telotarsus 0.33-0.35/0.03-0.04 (8.75-11.67).

Females: body length 1.61-1.71. Pedipalps: trochanter 0.15-0.19/0.08-0.09 (1.67-2.38), femur 0.57-0.60/0.10 (5.70-6.00), patella 0.25-0.26/0.11 (2.27-2.36), chela 0.81-0.85/0.15-0.16 (5.2), hand 0.39-0.41/0.15-0.16 (2.75), movable chelal finger length 0.43-0.45. Chelicera 0.34-0.37/0.19-0.21 (1.76-1.79), movable finger length 0.22-0.23. Carapace 0.35-0.36/0.34-0.37 (0.82-0.88). Leg I: trochanter 0.09-0.13/0.09 (1.33-1.44), femur 0.30-0.32/0.06-0.08 (3.75-5.33), patella 0.17-0.18/0.05-0.06 (2.83-3.60), tibia 0.16-0.17/0.04-0.05 (3.20-4.25), tarsus 0.34-0.35/0.04 (8.50-8.75). Leg IV: trochanter 0.15-0.19/0.10-0.12 (1.50-1.58), femoropatella 0.49-0.54/0.21 (2.33-2.57), tibia 0.35-0.36/0.07 (5.00-5.14), basitarsus 0.15-0.16/0.06-0.07 (2.29-2.50), telotarsus 0.36-0.38/0.03-0.04 (9.50-12.00).

Remarks.

Lagynochthonius sanhuaensis sp. nov. most closely resembles L. niger in the absence of intercalary teeth and the presence of four setae on tergites I and II, but differs from it in several characters. First, the new species has a shorter (0.68-0.73 mm compared to 0.75-0.93 mm in L. niger ) and thinner chela (6.80-7.89 × as long as broad compared to 5.17-6.25 × as long as broad in L. niger ) in males. Second, the shape of the epistome is hump-shaped in L. sanhuaensis sp. nov., whereas it is triangular in L. niger . Third, the rallum has seven blades in L. sanhuaensis sp. nov., whereas it has eight blades in L. niger ( Hu and Zhang 2012a).

Distribution.

China (Guizhou Province).

Figures

Figure 18. Lagynochthonius sanhuaensis sp. nov. A holotype male (dorsal view) B paratype female (dorsal view).

Figure 19. Lagynochthonius sanhuaensis sp. nov., holotype male (A-F) paratype female (G): A left chela (lateral view) B left chela (dorsal view) C left chelicera (dorsal view) D carapace (dorsal view) E left pedipalp (minus chela, dorsal view) F male genital area (ventral view) G female genital area (ventral view).

Figure 20. Lagynochthonius sanhuaensis sp. nov., holotype male A carapace (dorsal view) B left chelicera (dorsal view), with details of teeth C rallum D coxal spines on coxae II (ventral view) E left pedipalp (minus chela, dorsal view).

Figure 21. Lagynochthonius sanhuaensis sp. nov., holotype male A left chela (lateral view), with details of teeth and trichobothrial pattern B left chela (dorsal view) C leg I (lateral view) D leg IV (lateral view). Abbreviations: for the chelal trichobothria: b = basal; sb = sub-basal; st = subterminal; t = terminal; ib = interior basal; isb = interior sub-basal; ist = interior sub-terminal; it = interior terminal; eb = exterior basal; esb = exterior sub-basal; est = exterior sub-terminal; et = exterior terminal. For other abbreviations: af, apical sensilla of fixed chelal finger, am, apical sensilla of movable chelal finger; dx, duplex trichobothria; p 1 - 2, proximal sensilla of movable chelal finger; td, modified tooth.