Tyrannochthonius huaerensis, 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 huaerensis sp. nov.

Figs 2 , 6C, D

Type material.

Holotype male: China, Sichuan Province, Luzhou City, Gulin County, Shipping Town, Xiangding Village, Huaer Cave, 28°02.22'N, 106°01.43'E, 760 m a.s.l., 3 November 2019, Yun-Chun Li leg., in MCWNU (Ar-Ps-SC-0052). Paratypes: 4 males, 2 females, collected with the holotype, in MCWNU (Ar-Ps-SC-0001).

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 very small; rallum composed of eight blades; tergites I-VI with four setae; chelal finger without intercalary teeth; coxae II with 12 terminally indented coxal spines on each side; chelal hand dorsal surface with chemosensory setae; apex of coxa I with long and rounded anteromedial process, near the apex without setae; movable finger retrolateral margins weakly curved between st and sb trichobothria; fixed chelal finger with 23 or 24 teeth, movable chelal finger with 14 or 15 macrodenticles and 7-9 vestigial teeth. Pedipalpal femur (♂) 8.92-8.95 ×, (♀) 8.54-8.59 × longer than broad, length (♂) 1.16-1.19 mm, (♀) 1.11-1.17 mm; chela (♂) 7.00-7.07 ×, (♀) 8.67-8.69 × longer than deep, length (♂) 1.61-1.64 mm, (♀) 1.56-1.58 mm; ratio movable chelal finger/chelal hand (♂) 1.56-1.59 ×, (♀) 1.52-1.55 ×.

Etymology.

Latinized adjective, derived from the type locality, namely Huaer Cave.

Description.

Adult male (Fig. 6C ).

Carapace, chelicera, pedipalps, and tergites I-VI reddish brown, remaining parts yellowish brown (Fig. 6C ).

Carapace (Fig. 2A ): 1.11-1.13 × longer than broad, no eyes or eyespots; epistome very small, triangular; 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 without setae (Fig. 2D ); coxae II with 12 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. 2B ): 2.31-2.33 × 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 12 or 13 teeth, distal one largest, decreasing in size proximally; movable finger with 13 or 14 teeth; galea absent. Serrula exterior with 20-22 blades. Rallum composed of eight blades (Fig. 2C ), 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. 2E-G ): all setae acuminate. Trochanter 1.25-1.30 ×, femur 8.92-8.95 ×, patella 2.75-2.78 × longer than broad and with one lyrifissure. Femur 2.64-2.70 × longer than patella. Chela 7.00-7.07 ×, hand 2.74-2.76 × longer than deep; movable chelal finger 1.56-1.59 × longer than hand. Chelal hand dorsal surface with a single row of seven chemosensory setae between esb and ib / isb trichobothria; distal paraxial seta of hand not enlarged. Fingers straight in dorsal view (Fig. 2G ). Fixed finger with 23 or 24 teeth, middle ones larger than those at both ends; movable finger with 14 or 15 macrodenticles, base of finger with 7-9 very low, vestigial teeth (Fig. 2F ). Venom apparatus absent. Movable finger retrolateral margins weakly curved between st and sb trichobothria. 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: 4: 3: 3: 4: 4: 2: 0; sternal chaetotaxy (IV-XII): 10: 10: 9: 9: 9: 11: 8: 0: 2. Anterior genital operculum with ten setae, genital opening slit-like, with 14 or 15 marginal setae on each side (Fig. 2H ). Legs: leg I: trochanter 1.58-1.59 ×, femur 8.25-8.30 × longer than deep and 2.00-2.04 × longer than patella; patella 4.71-4.75 ×, tibia 4.14-4.18 ×, tarsus 11.17-11.20 × longer than deep. Leg IV: trochanter 1.15-1.18 ×, femoropatella 3.33-3.39 ×, tibia 6.70-6.72 × longer than deep, basitarsus 3.75-3.79 × longer than deep, with a basal tactile seta (TS = 0.21-0.22), telotarsus 12.67-12.70 × longer than deep and 2.53-2.55 × longer than basitarsus, with a tactile seta near base (TS = 0.19-0.20). Arolia on legs I and IV shorter than claws.

Adult female (Fig. 6D ).

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

Carapace: slightly longer than broad (1.08-1.10 ×). Chelicera: 2.27-2.29 × longer than broad. Pedipalp: trochanter 1.81-1.84 × longer than broad, femur 8.54-8.59 × longer than broad, patella 2.87-2.89 × longer than broad, femur 2.58-2.60 × longer than patella. Chela 8.67-8.69 × longer than deep, hand 3.44-3.47 × longer than deep; movable finger 1.52-1.55 × longer than hand. Opisthosoma: tergal chaetotaxy (I-XII): 4: 4: 4: 4: 4: 4: 4: 4: 5: 4: 2: 0; sternal chaetotaxy (IV-XII): 10: 9: 9: 8: 10: 10: 8: 0: 2. Anterior genital operculum with 10 + 6 setae on posterior margin (Fig. 2I ).

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

Males (females in parentheses): body length 1.89-1.95 (1.87-1.99). Carapace 0.59-0.60/0.53-0.54 (0.53-0.55/0.49-0.51). Pedipalp: trochanter 0.20-0.22/0.16-0.18 (0.29-0.30/0.16-0.17), femur 1.16-1.19/0.13-0.15 (1.11-1.17/0.13-0.15), patella 0.44-0.45/0.16-0.17 (0.43-0.44/0.15-0.16), hand 0.63-0.65/0.23-0.25 (0.62-0.65/0.18-0.20), length of movable chelal finger 0.98-0.99 (0.94-0.97), chela 1.61-1.64/0.23-0.25 (1.56-1.58/0.18-0.20). Chelicera: 0.60-0.61/0.26-0.28 (0.59-0.60/0.26-0.27). Leg I: trochanter 0.19-0.20/0.12-0.14 (0.19-0.21/0.12-0.14), femur 0.66-0.69/0.08-0.09 (0.57-0.59/0.08-0.09), patella 0.33-0.35/0.07-0.08 (0.30-0.32/0.07-0.08), tibia 0.29-0.30/0.07-0.08 (0.29-0.30/0.06-0.07), tarsus 0.67-0.69/0.06-0.07 (0.65-0.67/0.05-0.06). Leg IV: trochanter 0.23-0.25/0.20-0.21 (0.17-0.19/0.14-0.16), femoropatella 0.90-0.92/0.27-0.29 (0.83-0.86/0.25-0.27), tibia 0.67-0.69/0.10-0.11 (0.62-0.64/0.10-0.11), basitarsus 0.30-0.32/0.08-0.09 (0.27-0.29/0.08-0.09), telotarsus 0.76-0.79/0.06-0.07 (0.70-0.74/0.05-0.06).

Distribution.

China (Sichuan).

Figures

Figure 2. Tyrannochthonius huaerensis sp. nov., holotype male (A-H) and paratype female (I) A carapace B right chelicera C rallum of left chelicera D process of left coxa I, ventral view E palp (minus chela) F chela, retrolateral view G chela, dorsal view H male genital area I female genital area. Scale bars: 0.20 mm.

Figure 6. A, B Tyrannochthonius dongjiensis sp. nov., dorsal views A holotype male B paratype female C, D T. huaerensis sp. nov., dorsal views C holotype male D paratype female. Scale bar: 1.00 mm (A-D).