Tyrannochthonius huilongshanensis, Li, 2022

Li, Yun-Chun, 2022, Five new troglobitic species of Tyrannochthonius (Arachnida, Pseudoscorpiones, Chthoniidae) from the Yunnan, Guizhou and Sichuan Provinces, China, ZooKeys 1131, pp. 173-195 : 173

Tyrannochthonius huilongshanensis sp. nov.

Figs 3 , 7A, B

Type material.

Holotype male: China, Yunnan Province, Dali City, Nanjian County, Xiaowan Town, Huilongshan Village, Banpoyan Cave, 24°56.01'N, 100°18.87'E, 1990 m a.s.l., 23 August 2018, Yun-Chun Li leg., in MCWNU (Ar-Ps-YN-0079). Paratypes: 2 males, 7 females, collected with the holotype, in MCWNU (Ar-Ps-YN-0012).

Diagnosis.

Troglobiont habitus. This new species is distinguished from other members of the genus Tyrannochthonius by the following combination of characters: carapace without eyes or eyespots, anterior margin with four- setae; epistome present; tergites I-V with four setae; coxae II with eight terminally indented coxal spines on each side; apex of coxa I with long and rounded anteromedial process, near the apex with a seta; chelal hand dorsal surface with chemosensory setae; fixed chelal finger with 28 teeth and 16 or 17 intercalary teeth, movable chelal finger with 15 or 16 macrodenticles, 12 or 13 intercalary teeth and 5-7 vestigial teeth. Pedipalpal femur (♂) 4.87-4.90 ×, (♀) 5.33-5.37 × longer than broad, length (♂) 0.73-0.76 mm, (♀) 0.80-0.83 mm; chela (♂) 5.61-5.66 ×, (♀) 6.37-6.40 × longer than deep, length (♂) 1.01-1.09 mm, (♀) 1.21-1.25 mm; ratio movable chelal finger/chelal hand (♂) 1.75-1.80 ×, (♀) 1.80-1.83 ×.

Etymology.

Latinized adjective, derived from the village of Huilongshan, which is near the type locality.

Description.

Adult male (Fig. 7A ).

Chelicera reddish brown, remaining parts yellowish brown (Fig. 7A ).

Carapace (Fig. 3A ): 1.02-1.06 × longer than broad, no eyes or eyespots; epistome small, triangular, with two setae flanking base; carapace surface smooth, lateral margins distinctly constricted posteriorly. With 18 setae arranged 4: 6: 4: 2: 2, anterolateral setae much shorter than others. Coxae: manducatory process pointed, with two distal setae, one long and the other slightly shorter. Pedipalpal coxa with three setae, coxa I 3, II 4, III 5, IV 5; intercoxal tubercle absent. Apex of coxa I with long and rounded anteromedial process, near the apex with a seta; coxae II with eight terminally indented coxal spines on each side, set as an oblique row, longer spines present in the middle of the row, becoming shorter distally and proximally and incised for ~ ½ their length. Chelicera (Fig. 3B ): 2.25-2.29 × longer than broad, hand with five setae and one lyrifissure dorsally, movable finger with one submedial seta. Cheliceral hand with moderate hispid granulation dorsally. Fixed finger with eight or nine teeth, distal one largest, decreasing in size proximally; movable finger with 7-9 teeth; galea absent. Serrula exterior with 19-21 blades. Rallum composed of eight blades (Fig. 3C ), distal blade weakly recumbent basally, with fine barbules and set apart from the other blades, the latter tightly grouped and with long pinnae. Pedipalp (Fig. 3D-F ): all setae acuminate. Trochanter 1.60-1.61 ×, femur 4.87-4.90 ×, patella 1.61-1.64 × longer than broad and with one lyrifissure. Femur 2.52-2.55 × longer than patella. Chela 5.61-5.66 ×, hand 2.00-2.10 × longer than deep; movable chelal finger 1.75-1.80 × longer than hand. Chelal hand dorsal surface with a single row of five chemosensory setae between esb and ib / isb trichobothria; distal paraxial seta of hand not enlarged. Fingers straight in dorsal view (Fig. 3F ). Fixed finger with 28 teeth and 16 or 17 intercalary teeth, middle ones larger than those at both ends; movable finger with 15 or 16 macrodenticles and 12 or 13 intercalary teeth, base of finger with 5-7 very low, vestigial teeth (Fig. 3E ). Venom apparatus absent. Fixed chelal finger with eight trichobothria and movable finger with four, ib and isb situated close together, submedially on dorsum of chelal hand; eb, esb, and ist forming a straight oblique row at base of fixed chelal finger; it slightly distal to est, situated subdistally; et slightly nearer to tip of fixed finger; dx situated distal to et; sb near to st; b and t situated subdistally, t situated at same level as it. Opisthosoma: tergites and sternites undivided; setae uniseriate and acuminate. Tergal chaetotaxy (I-XII): 4: 4: 4: 4: 4: 6: 6: 6: 6: 4: 2: 0; sternal chaetotaxy (IV-XII): 8: 10: 6: 6: 6: 7: 7: 0: 2. Anterior genital operculum with ten setae, genital opening slit-like, with 11 or 12 marginal setae on each side (Fig. 3G ). Legs: leg I: trochanter 1.68-1.70 ×, femur 6.50-6.58 × longer than deep and 1.56-1.59 × longer than patella; patella 4.17-4.20 ×, tibia 4.00-4.06 ×, tarsus 8.40-8.47 × longer than deep. Leg IV: trochanter 1.00-1.07 ×, femoropatella 2.59-2.63 ×, tibia 4.40-4.47 × longer than deep, basitarsus 2.71-2.74 × longer than deep, with a basal tactile seta (TS = 0.15-0.17), telotarsus 9.60-9.66 × longer than deep and 2.53-2.55 × longer than basitarsus, with a tactile seta near base (TS = 0.15-0.16). Arolia on legs I and IV shorter than claws.

Adult female (Fig. 7B ).

Mostly the same as the holotype with the differences listed below.

Carapace: slightly longer than broad (0.90-0.99 ×). Chelicera: 2.13-2.17 × longer than broad. Pedipalp: trochanter 1.86-1.88 × longer than broad, femur 5.33-5.37 × longer than broad, patella 1.94-1.98 × longer than broad, femur 2.58-2.59 × longer than patella. Chela 6.37-6.40 × longer than deep, hand 2.11-2.15 × longer than deep; movable finger 1.80-1.83 × longer than hand. Opisthosoma: tergal chaetotaxy (I-XII): 4: 4: 4: 4: 5: 6: 6: 6: 5: 4: 2: 0; sternal chaetotaxy (IV-XII): 12: 10: 7: 8: 7: 7: 6: 0: 2. Anterior genital operculum with 10 + 17 setae on posterior margin (Fig. 3H ).

Dimensions (mm, length/width or, in the case of the legs, chela, and chelal hand, length/depth).

Males (females in parentheses): body length 1.68-1.75 (1.89-1.95). Carapace 0.44-0.46/0.43-0.44 (0.45-0.49/0.50-0.51). Pedipalp: trochanter 0.24-0.26/0.15-0.17 (0.26-0.28/0.14-0.16), femur 0.73-0.76/0.15-0.17 (0.80-0.83/0.15-0.17), patella 0.29-0.31/0.18-0.19 (0.31-0.33/0.16-0.17), hand 0.36-0.40/0.18-0.20 (0.40-0.44/0.19-0.20), length of movable chelal finger 0.63-0.67 (0.72-0.76), chela 1.01-1.09/0.18-0.20 (1.21-1.25/0.19-0.20). Chelicera: 0.45-0.47/0.20-0.22 (0.51-0.54/0.24-0.26). Leg I: trochanter 0.17-0.19/0.10-0.11 (0.16-0.18/0.14-0.15), femur 0.39-0.42/0.06-0.07 (0.45-0.46/0.08-0.09), patella 0.25-0.27/0.06-0.07 (0.28-0.30/0.07-0.08), tibia 0.20-0.22/0.05-0.06 (0.22-0.25/0.06-0.07), tarsus 0.42-0.45/0.05-0.06 (0.49-0.53/0.05-0.06). Leg IV: trochanter 0.16-0.17/0.16-0.17 (0.21-0.22/0.15-0.17), femoropatella 0.57-0.59/0.22-0.24 (0.54-0.57/0.20-0.22), tibia 0.44-0.46/0.10-0.11 (0.43-0.46/0.11-0.12), basitarsus 0.19-0.21/0.07-0.08 (0.21-0.23/0.08-0.09), telotarsus 0.48-0.50/0.05-0.06 (0.50-0.54/0.05-0.06).

Distribution.

China (Sichuan).

Figures

Figure 3. Tyrannochthonius huilongshanensis sp. nov., holotype male (A-G) and paratype female (H) A carapace B right chelicera C rallum of left chelicera D palp (minus chela) E chela, retrolateral view F chela, dorsal view G male genital area H female genital area. Scale bars: 0.20 mm.

Figure 7. A, B Tyrannochthonius huilongshanensis sp. nov., dorsal views A holotype male B paratype female C, D T. xinzhaiensis sp. nov., dorsal views C holotype male D paratype female. Scale bar: 1.00 mm (A-D).