Allochthonius xuae, sp. nov.
Creators: name: Yun-Chun LI
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Pseudotyrannochthoniidae
Allochthonius
Allochthonius xuae

description: Allochthonius xuae sp. nov.
urn:lsid:zoobank.org:act: C70C86D8-8E61-4684-AEE2-DA6EBE7D5171
Figs 2, 4C–D
Diagnosis
Differs from the other members of the genus Allochthonius by the following combination of characters: cheliceral hand with 7 setae, fixed cheliceral finger with large subapical tooth, rallum with 11 blades (each with fine barbules, the basal-most blade shorter than the others); coxae I with 8 tridentate blades, each blade with a central spine terminally distinctly expanded as fan-shaped, all situated on a common tubercle. Pedipalpal femur (♂) 5.21 ×, (♀) 5.59–5.61 × as long as broad, length (♂) 0.99 mm, (♀) 1.23– 1.24 mm; chela (♂) 4.81 ×, (♀) 4.20–4.24 × as long as broad, length (♂) 1.49 mm, (♀) 1.72–1.78 mm; ratio movable chelal finger/chelal hand (♂) 1.63 ×, (♀) 1.63–1.65 ×.
Etymology
The specific epithet was given in honour of Mrs Juan Xu, the wife of the author.
Type material
Holotype CHINA • ♂; Guizhou Province, Dafang County, Wenge Town, Sanhe Village, Yelaoda Cave; 27º10.900′ N, 105º28.278′ E; 1438 m a.s.l.; 23 Apr. 2019; Yun-Chun Li leg.; MCWNU (Ar-Ps-GZ-0056).
Paratypes CHINA • 5 ♀♀; same collection data as for holotype; MCWNU (Ar-Ps-GZ-0012).
Description
Adult male
COLOURS. Chelicerae and pedipalps reddish brown, remaining parts brown; carapace, chelicerae and abdomen with dense round white spots.
CARAPACE (Fig. 2A). 0.87 × as long as broad, scarcely constricted posteriorly, with 4 well-developed eyes; epistome absent, space between median setae slightly recurved. Carapace surface with 5 lyrifissures, near anterior and posterior margins. With 26 setae arranged 10: 4: 6: 2: 4.
CHELICERA. Relatively broad. Cuticle of hand gently granulate to squamate. Hand with 7 setae and 3 lyrifissures, all setae acuminate, movable finger with 1 seta in medial position, galea absent. Fixed finger with 4 conspicuous teeth, including 1 large subapical tooth, distinctly larger than others; movable finger with 21–23 teeth (Fig. 2B). Serrula exterior with 23–24 lamellae; serrula interior with 19–20
lamellae. Rallum composed of 11 blades with fine barbules, the apical-most one with 3 small branches at bend and basal-most 1 distinctly shorter than others (Fig. 2D).
PEDIPALP (Fig. 2E–G). All setae acuminate. Trochanter 1.47 ×, femur 5.21 ×, patella 2.47 × as long as broad, femur 2.36 × as long as patella. Chela 4.81 ×, hand 1.81 × as long as broad; movable chelal finger 1.63 × as long as hand. Fixed finger with 20 acute teeth, which middle ones larger than that in both ends; movable finger with 16 teeth, tubercle between 8 and 9. Fixed chelal finger with 8 trichobothria and movable finger with 4, eb, esb, ib, isb, and ist located basally of fixed finger and 2 special sensory hairs (xs) near the fingertip; on movable finger, st subproximal and in medial position on finger, triplet sb, b, and t distomedial to distal, distance between sb and b distinctly longer than distance between b and t.
ABDOMEN. Tergal chaetotaxy (I–XII): 4: 5: 7: 7: 8: 11: 11: 12: 10: 8: 2: 0; sternal chaetotaxy (IV–XII): 17: 16: 15: 16: 16: 12: 12: 0: 2. Manducatory process with 2 setae. Pedipalpal coxa with 3 setae, coxa I 5–6, II 5, III 7, IV 7 setae; intercoxal tubercle present with 2 setae. Coxal blades only present on coxa I, with spray of 8 clavate blades (Fig. 2C). Anterior genital operculum with 8 setae, without lyrifissures; genital opening with 14 setae on the right side, and 12 on the left (Fig. 2H).
LEGS. Leg I: trochanter 1.16 × as long as deep, femur 5.09 × as long as deep and 1.60 × as long as patella, patella 3.50 × as long as deep, tibia 4.57 × as long as deep, tarsus 9.43 × as long as deep. Leg IV: trochanter 0.90 × as long as deep, femur+patella 3.28 × as long as deep, femur shorter than patella, tibia 4.86 × as long as deep, metatarsus 3.67 × as long as deep, tarsus 11.33 × as long as deep. Metatarsus with 1 tactile seta (sub-basal, TS = 0.28), tarsus with 2 tactile setae (sub-basal, TS = 0.29; subterminal, TS = 0.20). Arolia shorter than claws, latter slender and smooth.
Adult female
Mostly the same as the holotype.
CARAPACE. 0.83–0.87 × as long as broad.
PEDIPALP. Trochanter 1.43–1.44 × as long as broad, femur 5.59–5.61 × as long as broad, patella 2.23– 2.25 × as long as broad, femur 2.51–2.54 × as long as patella. Chela 4.20–4.24 × as long as broad, hand 1.59–1.62 × as long as broad; movable finger 1.63–1.65 × as long as hand.
ABDOMEN. Tergal chaetotaxy (I–XII): 4: 5: 7: 9: 11: 11: 10: 14: 11: 10: 2: 0; sternal chaetotaxy (IV–XII): 18: 18: 16: 15: 16: 14: 12: 0: 2. Genital opening slit-like, anterior genital operculum with 17 setae, with 2 lyrifissures (Fig. 2I).
DIMENSIONS (length/width or, in the case of the legs, length/depth in mm). Male (females in parentheses): body length 2.92 (3.70–3.77). Carapace 0.52/0.60 (0.58–0.61/0.70–0.72). Pedipalp: trochanter 0.22/0.15 (0.30–0.32/0.21–0.23), femur 0.99/0.19 (1.23–1.24/0.22–0.23), patella 0.42/0.17 (0.49–0.51/0.22–0.23), hand 0.56/0.31 (0.65–0.67/0.41–0.44), length of movable chelal finger 0.91 (1.06–1.10), chela 1.49/0.31 (1.72–1.78/0.41–0.44). Leg I: trochanter 0.22/0.19 (0.20–0.22/0.16–0.18), femur 0.56/0.11 (0.64– 0.67/0.13–0.14), patella 0.35/0.10 (0.41–0.44/0.12–0.13), tibia 0.32/0.07 (0.39–0.41/0.09–0.10), tarsus 0.66/0.07 (0.73–0.75/0.08–0.09). Leg IV: trochanter 0.19/0.21 (0.32–0.34/0.25–0.26), femur+patella 0.82/0.25 (0.91–0.95/0.31–0.33), tibia 0.68/0.14 (0.76–0.79/0.17–0.19), metatarsus 0.33/0.09 (0.37– 0.39/0.11–0.12), tarsus 0.68/0.06 (0. 69–0.70/0.08–0.09).
Distribution
China (Guizhou).
Habitat
The cave was about 20–200 m high, the length was unknown, and the width was about 50– 200 m. The new species were collected from under wet, dimly lit rubble about 100 m from the cave entrance. The surrounding herbs were abundant, and some spiders, millipedes and Carabidae were also collected.
description: Published as part of Yun-Chun LI, 2023, Three new species of pseudoscorpions (Arachnida: Pseudoscorpiones: Pseudotyrannochthoniidae) from caves in Yunnan and Guizhou Provinces, China, pp. 48-64 in European Journal of Taxonomy 861 on pages 53-56, DOI: 10.5852/ejt.2023.861.2065, http://zenodo.org/record/7729666