Lagynochthonius zhaoae, Sun, Guo & Zhang, 2024

SUN, JIANZHOU, GUO, XIANGBO & ZHANG, FENG, 2024, A review of the genus Lagynochthonius Beier, 1951 (Pseudoscorpiones, Chthoniidae) from China, Megataxa 12 (2), pp. 177-250 : 243-248

Lagynochthonius zhaoae sp. nov.

Chinese name. ẾƂȗ伪Dz

Figs 54–58

Typematerial. Holotype ♀ (Ps.- MHBU-GX2023113001 ): China, Guangxi Zhuang Autonomous Region, Guilin City, Xingan County, cave without name (Unnamed Cave 8) [25.581534°N, 110.62378374°E], 229 m a.s.l., 30 November 2023, Jiaqi Zhao, Songtao Shi, Tao Zheng & Jianzhou Sun leg.

Etymology. This species is named for Jiaqi Zhao, who participated in field work and collected some of the specimens.

Diagnosis. (♀). small sized hypogean species; galea slightly bumped; carapace with two eyespots, anterior margin smooth and epistome small and triangular; tergites Ⅰ–ⅠⅠ each with two setae, tergites ⅠⅠⅠ–ⅠV each with four setae. Pedipalps slender, chela 5.78 times as long as broad; femur 6.82 times as long as broad; both chelal fingers without intercalary teeth and a modified accessory tooth (td) on prolateral-retrolateral face; chemosensory setae (sc) present on dorsum of chelal hand.

Description. Adult female ( Figs 54 , 55 , 56 , 57 ).

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

Cephalothorax ( Figs 55D , 56A ): carapace nearly subquadrate, 0.93 times as long as broad, weakly constricted basally; posterior region with squamous sculpturing laterally, other area smooth, without furrows; anterior margin smooth, without serrations; epistome strongly point, with two eyespots; with 18 setae arranged s4s: 4: 4: 2: 2, most setae heavy, long and gently curved, anterolateral setae much shorter than others; with three pairs of lyrifissures, first and second pair situated middle and flank to the setae of ocular row, third pair situated lateral to the sole pair of setae of posterior row. Manducatory process with two acuminate distal setae, anterior seta more than 1/2 length of medial seta; apex of coxa I with a rounded anteromedial process; coxae II with 11 terminally indented coxal spines on each side, set as an oblique and arc row, central spines slightly longer than the others ( Fig. 55D ); intercoxal tubercle absent; chaetotaxy of coxae: P 3, I 3, II 4, III 5, IV 5.

Chelicera ( Figs 55C , 56B ):almost as long as carapace, 1.86 times as long as broad; five setae and two lyrifissures (exterior condylar lyrifissure and exterior lyrifissure) present on hand, all setae acuminate, ventrobasal setae shorter than others; movable finger with one medial seta. Cheliceral hand with moderate wrinkle on both ventral and dorsal sides. Both fingers well provided with teeth, fixed finger with 13 teeth, distal one largest; movable finger with 10 retrorse contiguous small teeth; galea represented by a very slight bump on movable finger ( Fig. 56B ). Serrula exterior with 18 and serrula interior with 14 blades. Rallum with eight 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. 56C ).

Pedipalp ( Figs 55A–B, 55E , 56E , 57A–B ): trochanter 2.00, femur 6.82, patella 2.54, chela 5.783, hand 2.39 times as long as broad; femur 2.68 times as long as patella; movable chelal finger 1.44 times as long as hand and 0.60 times as long as chela. Setae generally long and acuminate. Chelal hand 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 slightly distal eb and ist slightly distal to esb; it slightly distal to est, situated subdistally; et slightly near to tip of fixed chelal finger, slightly close to chelal teeth; dx situated distal to et; sb slightly closer to st than to b; b and t situated subdistally, t slightly distal to it and distal to b; est situated distal to b and close to it ( Figs. 55A , 57A ). Microsetae (chemosensory setae) present on dorsum of chelal hand ( Figs. 55B , 57B ). Both chelal fingers with a row of teeth, spaced regularly along the margin, teeth smaller distally and proximally: fixed finger with 18 well-spaced, pointed teeth, and a modified accessory tooth on prolateral-retrolateral face (td, slightly distal to dx); movable finger with 8 well-spaced, pointed teeth, plus 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: 2: 2: 4: 4: 4: 5: 5: 7: 7: 4: T2T: 0. Sternal chaetotaxy IV– XII: 10: 10: 9: 9: 10: 9: 9: -: 2. Genital region: sternite II with 10 setae scattered on median area, sternite III with a row of 10 setae. ( Fig. 55F ).

Legs ( Fig. 57C–D ): fine granulation present on anterodorsal faces of femur IV and patella IV. Leg Ⅰ: femur 1.80 times as long as patella; tarsus 2.10 times as long as tibia. Leg IV: femoropatella 3.11 times as long as deep; tibia 4.88 times as long as deep; with basal tactile setae on both tarsal segments: basitarsus 3.00 times as long as deep (TS = 0.33), telotarsus 10.75 times as long as deep and 2.39 times as long as basitarsus (TS = 0.28). Setae of leg I (trochanter to tibia) 2: 7: 7: 10, setae of leg IV (trochanter to basitarsus) 2: 3: 6: 9: 10. Arolium not divided, slightly shorter than the simple claws.

Dimensions (length/breadth or, in the case of the legs, length/depth in mm; ratios in parentheses). Female: body length 1.47. Pedipalps: trochanter 0.22/0.11 (2.00), femur 0.75/0.11 (6.82), patella 0.28/0.11 (2.54), chela 1.04/0.18 (5.7), hand 0.43/0.18 (2.39), movable chelal finger length 0.62. Chelicera 0.39/0.21 (1.86), movable finger length 0.23. Carapace 0.41/0.44 (0.93). Leg I: trochanter 0.13/0.09 (1.82), femur 0.36/0.07 (5.14), patella 0.20/0.06 (3.33), tibia 0.20/0.05 (4.00), tarsus 0.42/0.04 (10.50). Leg IV: trochanter 0.19/0.11 (1.73), femoropatella 0.56/0.18 (3.11), tibia 0.39/0.08 (4.88), basitarsus 0.18/0.06 (3.00), telotarsus 0.43/0.04 (10.75).

Remarks. Lagynochthonius zhaoae sp. nov. closely resembles L. zhakouensis sp. nov. in the absence of intercalary teeth, the presence of two setae on tergites I–II, the presence of four setae on tergites III–IV, and the presence of two eyespots on the carapace, but differs in the following characters: thinner chela femur (6.82 (♀) times longer than broad vs 7.80 (♀) times longer than broad in L. zhakouensis sp. nov.) and small and triangular epistome (vs. epistome absent in L. zhakouensis sp. nov.).

Ecology. The specimen was collected under mud inside the cave.

Distribution. Known only from the type locality ( China, Guangxi Zhuang Autonomous Region).

Figures

FIGURE 54. Lagynochthonius zhaoae sp. nov., holotype female (dorsal view).

FIGURE 55. Lagynochthonius zhaoae sp. nov., holotype female: 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. Carapace (lateral view), indicate eyespot (red arrow); G. Female genital area (ventral view).

FIGURE 56. Lagynochthonius zhaoae sp. nov., holotype female: 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 57. Lagynochthonius zhaoae sp. nov., holotype female: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).

FIGURE 58. Unnamed Cave 8, Type locality of Lagynochthonius zhaoae sp. nov., A–B. Entrance; C. Inside the cave entrance; D. Areas where L. zhaoae sp. nov. specimens were collected.