Cybaeodamus malkini sp. nov.

urn:lsid:zoobank.org:act: 354DEC2C-0C56-420C-86FE-A4EC45163812

Figs 14–17

Diagnosis

The male of this species resembles that of C. tocantins by sharing the group of strong macrosetae at the posterior tip of the sternum and the retromargin of the fourth coxae (Fig. 14C, I vs Lise et al. 2009: fig. 61), and by the shape of the RTA (Figs 16C, E, 17C vs Lise et al. 2009: fig. 65). These characteristics differentiate these species from all other congeners. However, C. malkini sp. nov. differs from C. tocantins by the shape of its tegular sclerites (Figs 16B, D, 17A–B, D–E vs Lise et al. 2009: fig. 63), and by the absence of a ventral process on both the coxae and femur of leg III (see Lise et al. 2009: fig. 62).

Remark

In the diagnosis of C. tocantins by Lise et al. (2009), a ventral process on femur IV is mistakenly mentioned. However, the description and the fig. 62 refer to a ventral process on both the coxae and femur of leg III, which should align with the observed morphology.

Etymology

The specific name is a patronym in honour of Borys Malkin a dedicated naturalist and collector of the holotype.

Material examined

Holotype BRAZIL • ♂; Mato Grosso, Santa Terezinha, Barra do Tapirapé; 10°28′14.9″ S, 50°30′22.7″ W; 11–30 Dec. 1960; B. Malkin leg.; AMNH.

Description

Male holotype (Figs 14–17)

BODY MEASUREMENTS. Total length 4.83; carapace 2.65 long, 1.78 wide, narrowed to 1.15 in front, 0.92 high.

COLOUR IN ETHANOL (Fig. 14A–B, D–E). Carapace, cephalic area yellowish brown, cephalic groove dark brown, thoracic area medium brown with transverse pale stripes, half as long as carapace width, crossing middle of dark brown fovea; chelicerae, labium and endites medium brown, distally paler; sternum medium brown, paler towards centre; legs and palps pale yellow, with femora darker, medium brown; abdomen and spinnerets entirely pale cream.

CARAPACE (Fig. 14A, D–E). Oval, with marked constriction at palp trochanter level; profile slightly doomed, with slight depression at level of fovea, highest point posterior to fovea.

EYE (Fig. 14F). Sizes and interdistances: AME: 0.09; ALE: 0.11; PME: 0.10: PLE: 0.11; AME–AME: 0.03; AME–ALE: 0.04; AME–PME: 0.05; AME–PLE: 0.06; ALE–ALE: 0.16; ALE–PLE: 0.03; ALE– PME: 0.15; PME–PME: 0.04; PME–PLE: 0.08. MOQ: frontal width 0.21, posterior width 0.24, length 0.24.

CLYPEUS (Fig. 14E–F). 0.11 high, provided with few thick setae. Chilum not visible. Chelicerae (Fig. 14G) 0.76 long, densely covered with setae, promargin with two teeth, retromargin without.

STERNUM (Fig. 14B–C, I). Elongate oval, 1.28 long, 0.92 wide, lateral margins sinuous, cover of setae denser laterally, posteriorly with group of long, thick macrosetae.

LEGS (Fig. 14A–E, I). Femora ventrally with long bristles, denser on hind legs; coxae IV inflated basoretrolaterally, touching each other, with retrolateral longitudinal brush of long, thick macrosetae (Fig. 14I). Leg formula 4132 (Table 4). Leg spination as in Fig. 15.

ABDOMEN (Fig. 14A–C). Ovoid, venter medially with dense, oval patch of small, thick, spine-shaped setae (Fig. 14H).

PALP (Figs 16–17). Femur 1.10 long; tibia ventrally with group of long, curved setae; RTA provided with two prongs: superior one with prolateral side concave, with distal part slightly curved down, blunt tip, three times as long, inferior one (VP) with slightly sharper tip; cymbium ovoid, prolaterally with five strong spines and subapically with two ventral spines, with stout probasal flange (PCF) and slender retrolateral flange (RCF); tegulum complex with two narrow prongs pointing forward: one straight (TA), cylindrical with blunt tip, obliquely situated in the middle (Fig. 16A), other one (MA) retroanteriorly placed, slightly longer and sickle-shaped with sharp tip (Fig. 16B); subtegulum (St) emerging prolaterally as strongly sclerotized knob; conductor (C) large, folded; embolus (E) originating proanteriorly, above prolateral subtegular knob, simple, slender, emerging straight retrolaterad, then apically slightly curved, base with small boss prolaterally.

Female

Unknown.

Distribution

The species is known only from the type locality in Brazil (Fig. 18).