Afromygale pinnipalpis, Zonstein, 2020

Zonstein, Sergei L., 2020, On Afromygale, a new mygalomorph spider genus from East Africa (Araneae: Pycnothelidae), Israel Journal of Entomology (Oxford, England) 50 (1), pp. 131-146 : 139-143

Afromygale pinnipalpis n. sp.

( Figs 12–21)

LSID: urn:lsid:zoobank.org:act:7109E3DB­243C­4AB2­98EB­77A459624647 .

Etymology: The species name is a Latin adjective composed of nouns pinna (a fin) and palpus (a palp), thus meaning ‘fin­palped’. The specific epithet refers to a fin­shaped membranous embolic keel characteristic for this species.

Diagnosis: The new species differs from Afromygale rukanga n. sp. by a posteriorly broader sternum, as well as by a number of the male characters: by a relatively wide (broader than long) tegulum, an obtuse­ending embolic keel, and a shorter distal portion of the embolus (vs. a posteriorly narrower sternum, a narrower tegulum, an angularly ending keel, and a longer distal embolus; Figs 15, 19, 20 cf. Figs 6, 9, 10).

Description: Male (holotype). Total length 14.80.

Colour in alcohol: carapace and most part of palps and legs medium to dark ochre brown, with cephalic portion of carapace noticeably lighter than thoracic part; darkened eye tubercle brown; chelicerae dark brownish orange; labium, sternum, all coxae including maxillae, entire palp, and distal segments of legs I–IV pale yellowish brown; abdomen and spinnerets pale ochre brown, darker brown dorsal abdominal pattern, as in preceding species, formed by narrow dashed median stripe and several pairs of short lateral chevrons.

Cephalothorax dorsally and ventrally as in Figs 12 and 15, respectively. Carapace 6.61 long, 6.18 wide. Eye tubercle as in Fig. 13. Eye diameters and interdistances: AME 0.24 (0.32), ALE 0.32, PLE 0.25, PME 0.18, AME­AME 0.12 (0.04), AME­ ALE 0.07 (0.03), ALE­PLE 0.09, PLE­PME 0.03, PME­PME 0.61. Chelicerae, each carrying dense brush of partially broken setae on distal edge, as in Fig. 14. Cheliceral furrow with 7–8 promarginal teeth and about 30 mesobasal denticles arranged as in A. rukanga n. sp. Male intercheliceral tumescence and maxillary serrula indiscernible. Labium 0.81 long, 1.34 wide. Sternum 3.54 long, 3.02 wide.

Palp and leg structures. Tibia and metatarsus I as in Fig. 16; tarsus I as in Fig. 17. Spines (palpal patella and patella IV, palpal tibia, cymbium and tarsi I–IV aspinose): Palp: femur d0–1–1–1, pd1. Leg I: femur d1–1–1–1, pd0–1(0)–1, rd1(0)–1–0; patella p1; tibia p0–1–1, v2–2–1; metatarsus p0–1–0, v0–1–2. Leg II: femur d1–1–1–1, pd1–1–0, rd0–1–0; patella p0–1; tibia p0–1–1, v2–2–3; metatarsus p1–1–1, v2–2–2. Leg III: femur d1–1–1–1, pd1–1–0, rd0–1–0; patella p2(1)–2(1)–2; tibia d1–1, p1–1, r1–1, v2–2(1)–2; metatarsus d1–1–1, p1–1–1–1, r1–1–1, v2–1–2. Leg IV: femur d1–1–1–1, rd0–0–1; tibia p0–1–1, r1–1–1, v2–2–3(2); metatarsus d1–1–1, p1–1–1, r1–1–1, v2–1–0–1–3. Trichobothria: 2 rows of 7–8 each on tibiae I–IV (6–7 in each of two rows on palpal tibia), 10–12 on metatarsi, 12–15 on tarsi, 8–9 on cymbium. Scopula entire on tarsi I–III, absent on metatarsi I–IV and on tarsus IV. PTC I–II and III–IV with 7–9 and 6–8 teeth on each margin, respectively. Unpaired claw on tarsi I–IV very small, more reduced in size than in preceding species.

Leg measurements:

Palp I II III IV

Femur 4.48 5.91 5.52 4.69 6.60

Patella 2.19 2.74 2.49 2.14 2.76

Tibia 3.18 4.10 3.69 2.89 4.94

Metatarsus – 4.27 3.97 4.38 5.75

Tarsus 1.12 2.43 2.40 2.49 2.78

Total 10.97 19.45 18.07 16.59 22.83

Distal segments of pedipalp and copulatory organ as in Fig. 18. Embolus short, tapering and curved, carrying proximally longitudinal and semi­transparent membranous keel with obtuse distalmost edge ( Figs 19, 20).

Spinnerets ( Fig. 21). PMS: length 0.69, diameter 0.28. PLS: maximal diameter 0.68; length of basal, medial and apical segments 1.27, 0.67, 0.72; total length 2.66; apical segment triangular.

Female. Unknown.

Holotype: ♂ Tanzania: Arusha Region: surroundings of Arusha (“Ost­Afrika, Arüscha”, according to the original label), collector and collection date remain unknown, most probably the spider was collected during the German Ost­Afrika period, between 1890 and 1914 (SFM 3122). This specimen stored in alcohol for several decades was found to be somewhat bleached and contaminated by debris; the left legs are partially separated and kept together with the spider in the same vial: femur to tarsus I, metatarsus and tarsus II, tibia to metatarsus III, and tarsus IV.

Distribution: The species is known only from the type locality.

Ecology: Unknown.