Tetralycosa caudex sp. nov.

urn:lsid:zoobank.org:act: 5390F04B-FA2D-40FD-BA4C-78777A 071684

Figs 5 I–J; 8A–B; 9

Diagnosis

Tetralycosa caudex sp. nov. is very similar to T. arabanae (see ‘Diagnosis’ there).

Etymology

The specific epithet is a noun in apposition, from the Latin ‘ caudex ’, wooden stem, in reference to the type locality, Woodstock Station.

Type material

Holotype

AUSTRALIA: ♀, Western Australia, Woodstock Station, 21°37′00″ S, 119°01′24″ E, pitfall trap, site WS9, trap #3, 27 Mar. 1988, W.F. Humphreys leg. ( WAM T55570).

Other material examined

AUSTRALIA, Western Australia: 10 ♀♀, 1 ♀ with spiderlings, 23 juvs, Woodstock Station, 21°37′00″ S, 119°01′24″ E ( WAM T55576, T62493, T62497, T62611).

Description

Male

Unknown.

Female (based on holotype, WAM T55570)

MEASUREMENTS. ♀ holotype, WAM T53393: TL 7.80, CL 3.83, CW 2.28. Eyes: AME 0.20, ALE 0.16, PME 0.33, PLE 0.23. Row of eyes: AE 0.80, PME 0.74, PLE 0.97. Sternum length/width: 1.73/1.43.

Labium length/width: 0.57/0.53. AL 3.98, AW 3.00. Legs: Lengths of segments (femur + patella/tibia + metatarsus + tarsus = total length): Pedipalp 1.49+1.52+ – + 0.92 = 3.93, I 2.80+3.38+2.17+1.06 = 9.41, II 2.57+3.09+2.15+1.06 = 8.87, III 2.55+2.89+2.37+1.26 = 9.07, IV 3.20+4.35+3.03+1.54 = 12.12.

VARIATION. ♀ (range, mean ± SD): TL 5.85–9.00, 7.18 ± 1.07; CL 3.00–4.20, 3.56 ± 0.47; CW 2.25– 3.15, 2.70 ± 0.36; n = 8.

CARAPACE ( Fig. 5I). Dorsal line straight in lateral view; yellow-brown with lighter radial pattern; cephalic area slightly darker; indistinct grey pigmentation anteriorly of fovea, few white setae along carapace margins and laterally of PE; brown macrosetae in eye region and between eye region and fovea; six long bristles below AME, one long bristle between AME.

EYES. Row of AE slightly wider than row of PME; row of AE straight.

CHELICERAE. Brown; covered with brown setae and macrosetae. Two promarginal teeth, with the apical largest, three retromarginal teeth, with the basal smallest.

STERNUM ( Fig. 5J). Yellow-brown; covered with long brown setae.

LABIUM. Dark brown, basally darker; front end truncate and white.

ABDOMEN. Dorsally olive-brown with pairs of irregular lighter patches; indistinct brown lanceolate heart mark; mainly brown and fewer white setae, few brown macrosetae ( Fig. 5I). Venter yellow-brown with brown setae. Spinnerets yellow-brown ( Fig. 5J).

EPIGYNE. Ventral view ( Fig. 8A): median septum inverted T-shaped with rounded anterior curves; anterior margin continuous and nearly straight. Dorsal view ( Fig. 8B): large bulbous spermathecal heads; spermathecal stalks slim and attach posteriorly to spermathecae.

LEGS. Leg formula IV>I>III>II. Light brown, some grey pigmentation; basal two thirds of femora yellow-brown. Pedipalp with very long claw. Spination of leg I: femur: three dorsal, one apicoprolateral, two retrolateral; tibia: two ventral pairs, two prolateral; metatarsus: two ventral pairs, one prolateral, one apicoventral.

Remarks

Although the male of T. caudex sp. nov. is unknown, female somatic and genital morphology match the diagnosis of the genus and our phylogenetic analysis places it here. Some characters are unusual within the Tetralycosa; for example, T. caudex sp. nov. is the only species within the genus in which leg II is the shortest. In addition, the type and only locality of this species in northern Western Australia falls outside the general distribution of the genus ( Fig. 9).

Life history and habitat preferences

Only a limited number of female T. caudex sp. nov. have been found, some of them in granite with sand near a creek. Most records are from May, one female was found in March.

Distribution

Only known from the type locality, Woodstock Station in the Pilbara region of Western Australia ( Fig. 9).