Tyrannochthonius harveyi, Gao & Zhang & Chen, 2020

Gao, Zhizhong, Zhang, Feng & Chen, Huiming, 2020, Two new cave-dwelling species of Tyrannochthonius Chamberlin 1929 (Pseudoscorpiones: Chthoniidae) from the Guizhou karst, China, Zootaxa 4853 (4), pp. 572-580 : 573-576

Tyrannochthonius harveyi sp. nov.

Figs 1–3

urn:lsid:zoobank.org:act:D3AC481B-5A65-497F-A2DA-355F2B84D905

Type material. Holotype male (Ps.- MHBU-GZ11022201 ): China, Guizhou Province, Guiyang City, Huaxi District, Yutang Cave , dark zone, [26°25′015′′N, 106°393’058′′], elev. 1139 m, Temperature: 11°C, Humidity: 90%, 22 February 2011, Huiming Chen & Zuwei Zha leg. Paratype: one female (Ps.- MHBU-GZ11022202 ), same data as for holotype .

Etymology. The specific epithet is a patronym in honor of Dr. Mark S. Harvey, for the support he has granted over the past years in studying the Chinese pseudoscorpion fauna.

Diagnosis. Moderately-sized troglomorphic species (Body length 1.37–1.56); carapace without eyes or eyespots, anterior margin smooth, both anterior margin and posterior margin with 4 setae respectively, epistome rounded and inconspicuous; tergites I–III with 2 setae; chelal fixed finger without intercalary teeth, teeth on movable finger small, retrorse and continuous serrated; without chemosensory setae on dorsum of chelal hand.

Description. Adult male ( Fig. 1A ).

Colour: Generally pale yellow, chelicera, pedipalps and tergites slightly darker, soft parts pale.

Chelicera ( Figs 2C , 3B ): Five setae on hand, all setae acuminate; movable finger with one medial seta; fixed finger with 22 teeth and movable finger with 34 retrorse continuous small teeth; galea completely reduced; rallum ( Fig. 3D ) with 6 blades, the distal one longest, all blades long and bipinnate.

Pedipalp ( Figs 2A , 3 E–H): All setae acuminate; femur 6.29, patella 2.13, chela 7.50, hand 2.18 times longer than deep; movable finger 2.29 times longer than hand, without large basal apodeme, only slightly sclerotized section is present. Femur and dorsal hand without tactile setae. Fixed chelal finger and hand with 8 trichobothria, movable chelal finger with 4 trichobothria: 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 near to tip of fixed finger, very close to chelal teeth; dt situated distal to et; sb situated halfway between b and st; b and t situated subdistally, t situated at same level as est; b situated basal to est. Microsetae (chemosensory setae) absent on hand and both palpal fingers. Sensilla absent. Chelal teeth ( Fig. 3H ) homodentate: fixed finger with 20–21 large, erect, well-spaced teeth, without intercalary teeth; movable finger with numerous small, retrorse and continuous serrated teeth.

Cephalothorax ( Figs. 2B , 3A ): Carapace 1.04 times longer than broad; anterior margin smooth; lateral margins constricted posteriorly; without any traces of eyes; epistome rounded and inconspicuous; with 18 setae arranged 4: 4: 4: 2: 4; without furrows, preocular setae missing. Chaetotaxy of coxae: 4: 4: 4: 5; manducatory process with two acuminate distal setae, anterior seta less than 1/3 length of medial seta; coxae II with 8 terminally indented coxal spines on each side, set as an oblique row; intercoxal tubercle absent; without sub-oral seta.

Abdomen: Pleural membrane papillostriate. Tergites and sternites undivided; setae uniseriate and acuminate. Tergal chaetotaxy (I–XI): 2: 2: 2: 4: 4: 4: 4: 4: 4: 4: 4. Sternal chaetotaxy V–XI: 4: 6: 6: 6: 6: 6: 2 (longer setae). Anterior genital operculum with 11 setae plus 8 setae on posterior margin.

Legs ( Figs 3 I–J): Typical of the genus. Femur + patella of leg IV 3.23 times longer than deep; arolium slightly shorter than the claws, not divided; claws simple.

Measurements: (length/breadth or depth in mm, ratios in parentheses). Male holotype: Body length 1.37. Pedipalps: trochanter 0.24/0.14 (1.71), femur 0.88/0.14 (6.29), patella 0.32/0.15 (2.13), chela 1.20/0.16 (7.50), hand length 0.35/0.16 (2.18), movable finger length 0.80. Carapace 0.51/0.49 (1.04). Leg I: trochanter 0.16/0.12 (1.33), femur 1.33/0.07 (6.71), patella 0.25/0.06 (4.17), tibia 0.22/0.05 (4.40), tarsus 0.48/0.05 (9.60). Leg IV: trochanter 0.20/0.13 (1.54), femur + patella 0.71/0.22 (3.23), tibia 0.50/0.09 (5.56), basitarsus 0.22/0.07 (3.14), telotarsus 0.52/0.05 (10.40).

Female paratype: Mostly same as males, Anterior genital operculum with 9 setae plus 6 setae on posterior margin. Body length 1.56. Pedipalps: trochanter 0.28/0.14 (2.00), femur 0.87/0.15 (5.80), patella 0.36/0.16 (2.25), chela 1.30/0.18 (7.22), hand length 0.40/0.18 (2.22), movable finger length 0.83. Carapace 0.54/0.54 (1.00). Leg I: trochanter 0.17/0.12 (1.42), femur 0.44/0.07 (6.29), patella 0.20/0.07 (2.86), tibia 0.24/0.05 (4.80), tarsus 0.47/0.05 (9.40). Leg IV: trochanter 0.27/0.15 (1.80), femur + patella 0.73/0.23 (3.17), tibia 0.49/0.10 (4.90), basitarsus 0.23/0.08 (2.88), telotarsus 0.51/0.05 (10.20).

Remarks. Of the Chinesese species, Tyrannochthonius harveyi sp. n. is most similar to T. ganshuanensis in having only two setae on tergites I-III, but differs from the latter by the different setae number on anterior and posterior margin of carapace ( T. harveyi with 4 and 4 setae on anterior and posterior margin respectively, T. ganshuanensis with 6 and 2 setae, respectively), the shape of epistome (rounded and inconspicuous in T. harveyi , long and thin in T. ganshuanensis ), the stouter pedipalps (femur 6.29 vs. 6.60 times longer than broad), and the shape of teeth on pedipalpal movable finger (small, retrorse and continuously serrated, without intercalary teeth in T. harveyi , while well-spaced and with intercalary teeth in T. ganshuanensis ) ( Mahnert, 2009).

Figures

FIGURE 1. Tyrannochthonius harveyi sp. nov., A. holotype male, habitus, dorsal view; B. paratype female, habitus, dorsal view.

FIGURE 2. Tyrannochthonius harveyi sp. nov., holotype male (A–D), paratype female (E): A. Chelal fingers (lateral view); B. Carapace (dorsal view); C. Left chelicerae (dorsal view); D. Male genital area (ventral view); E. Female genital area (ventral view). Scale bars: 0.1 mm.

FIGURE 3. Tyrannochthonius harveyi sp. nov., holotype male: A. Carapace (dorsal view); B. Left chelicerae (dorsal view); C. Coxal spines of coxae II (ventral view); D. Rallum; E. Finger tips of chela (lateral view); F. Left pedipalp (minus chela, dorsal view); G. Left chela (lateral view); H. Chelal fingers (lateral view, showing the teeth); I. Leg I (lateral view); J. Leg IV (lateral view).. Scale bars: 0.10 mm (C–E); 0.25 mm (A–B, F–J).