Spinotrachelas, Haddad, 2006

Haddad, Charles R., 2006, Spinotrachelas, a new genus of tracheline sac spiders from South Africa (Araneae: Corinnidae), African Invertebrates 47, pp. 85-93 : 87

Spinotrachelas gen. n.

Etymology:This genus takes its name from the spiny legs and its superficial resemblance to the genus Trachelas . Gender masculine.

Type species: Spinotrachelas capensis sp. n.

Diagnosis: Spinotrachelas superficially resembles Trachelas and the Asian genus Utivarachna Kishida, 1940 in its general appearance ( Fig. 1 ), but can be distinguished from all tracheline genera by the presence of strong prolateral spines on the femora and patellae and paired spines on the tibiae of the first pairs of legs of both males and females, in addition to metatarsal and tarsal cusps ( Figs 2–7 ). These leg spines are evident in all instars. Males have a large number of short, peg-like cusps on the metatarsi and tarsi of legs I and II, while the females lack cusps on all leg segments except the tarsi of leg I. Spinotrachelas are black in colour and have pale yellow bands on the legs. The abdominal scutum covers the entire abdominal dorsum in males, but is absent in females.

Description: Small spiders, <5mm in size, black in colour; AER procurved, AME <ALE; AME closer to ALE than to each other; PER strongly recurved, PME> PLE; PME closer to each other than to PLE; carapace broadly oval, slightly narrowed laterally behind eye region, straight posteriorly; widest at midpoint; legs I and II longer and more strongly built than legs III and IV; legs with bands on tibiae; legs I and II with long spines prolaterally on femora and patellae, and paired ventrolateral spines on the tibiae; metatarsi and tarsi of males with two rows of strongly developed, peg-like cusps, present only on tarsus I of females; leg formula 1243; abdomen oval, tapering posteriorly, black with median paired transverse yellow markings ( Fig. 1 ); male with complete dorsal scutum, absent in females; inframamillary sclerite absent.

Figures

Fig. 1. General habitus of male Spinotrachelas capensis sp. n. Scale bar = 1 mm.

Figs 2–13. Spinotrachelas capensis sp. n., male: (2) leg I, indicating the presence of tibial spines (TS), and cusps (CU) on metatarsi; (3) leg I, indicating prolateral femoral spine (FS), prolateral patellar spine (PS) and paired tibial spines (TS); (4) metatarsus I, cusp arrangement, ventral view; (5) proximal cusp, enlarged; (6) metatarsus II, lateral view; (7) proximal cusp, enlarged; (8) dorsal view of carapace, showing carapace depression (CD); (9) mouthparts, showing cheliceral keel (CK) and serrula (SER) on endites; (10) serrula, enlarged; (11) spinnerets; (12) distal end of tarsus II, indicating tarsal claws (TC); (13) dorsal view of cymbium, indicating modified distal pair of setae.