Crossopriza tiwi Huber 2022, sp. nov.

Crossopriza tiwi sp. nov.

urn:lsid:zoobank.org:act: 740EB862-E768-4F8A-8E25-84A54D43403E

Figs 352, 393–395, 433–449

Diagnosis

Distinguished from known congeners by details of male palp (Figs 437, 440; procursus tip with short ventral sclerite and wide dorsal membranous element; distal bulbal sclerite with distinctive set of prolateral teeth and ridges); from the similar C. sahtan sp. nov. also by male chelicerae (Figs 438– 439; distal apophyses wider apart relative to width of chelicerae; proximal frontal processes much less distinct) and by shape of epigynum (Fig. 446; longer, anteriorly evenly curved).

Etymology

The species name refers to the type locality; noun in apposition.

Type material

Holotype OMAN – Ash Sharqiyah South • ♂; Wadi Tiwi; 22.801° N, 59.240° E; 60 m a.s.l.; 22 Mar. 2017; B.A. Huber leg.; ZFMK Ar 22401.

Other material examined

OMAN – Ash Sharqiyah South • 10 ♂♂, 7 ♀♀; same collection data as for holotype; ZFMK Ar 22402, Ar 22403 • 1 ♂, 3 ♀♀, 1 juv. (in pure ethanol); same collection data as for holotype; ZFMK Om 26 • 1 ♂; 8 km NNW of Wadd; 22.6136° N, 59.2919° E; 430 m a.s.l.; 18 Feb. 2018; B.A. Huber leg.; ZFMK Ar 22404 • 1 juv. (in pure ethanol); same collection data as for preceding; ZFMK Om 119 • 1 ♀; between Sur and Al Kamil; 22.463° N, 59.387° E; 90 m a.s.l.; 23 Mar. 2017; B.A. Huber leg.; in wadi; ZFMK Ar 22405 • 7 ♂♂, 6 ♀♀; between Sur and Al Kamil; 22.4646° N, 59.3881° E; 95 m a.s.l.; 18 Feb. 2018; B.A. Huber leg.; palm garden; ZFMK Ar 22406, Ar 22407 • 3 ♀♀, 2 juvs (in pure ethanol); same collection data as for preceding; ZFMK Om 117. – Ash Sharqiyah North • 3 ♀♀; Wadi Bani Khalid, outside of Mukal (Moqal) Cave; 22.624° N, 59.097° E; 700 m a.s.l.; 23 Mar. 2017; B.A. Huber leg.; ZFMK Ar 22408.

Description

Male (holotype)

MEASUREMENTS. Total length 4.1, carapace width 1.7. Distance PME–PME 75 µm; diameter PME 130 × 150 µm; distance PME–ALE 30 µm; diameter AME 100 µm; distance AME–AME 20 µm. Leg 1: 49.7 (14.9 + 0.7 + 12.9 + 18.5 + 2.7), tibia 2: 9.1, tibia 3: 6.5, tibia 4: 7.7; tibia 1 L/d: 65; femora 1–4 diameters: 0.31, 0.25, 0.22, 0.24.

COLOR (in ethanol). Carapace ochre-yellow, anteriorly in median pit light brown; sternum dark brown with black radial marks; legs ochre-yellow, without darker rings, with black lines on femora and (few) on tibiae; abdomen pale gray, with some dark marks dorsally and posteriorly above spinnerets; ventrally with distinct black pattern, with three parallel longitudinal marks behind gonopore.

BODY. Habitus as in Figs 393–394. Ocular area slightly raised. Deep thoracic pit and pair of furrows diverging from pit toward posterior margin. Clypeus unmodified, only rim slightly more sclerotized than in female. Sternum wider than long (1.2/0.8), unmodified. Abdomen slightly elongated, dorsoposteriorly angular.

CHELICERAE. As in Figs 438–439, with pair of latero-distal apophyses provided with one large modified cone-shaped hair each; distance between tips of modified hairs: 360 µm; lateral stridulatory ridges clearly visible in dissecting microscope.

PALPS. As in Figs 433–435; coxa with rounded retrolateral hump; trochanter barely modified; femur distally strongly widened, with rounded ventral protrusion, proximally with prolateral stridulatory pick, with indistinct retrolateral transversal line, without retrolateral proximal process; femur-patella joints shifted toward prolateral side; tibia-tarsus joints slightly shifted toward retrolateral side; tarsus without macrotrichia; procursus straight, with prolateral proximal hump set with many long hairs, long dorsal hairs not or only weakly curved, procursus tip (Figs 436–437) with strong ventral sclerite and further distinctive membranous and sclerotized elements; genital bulb (Figs 440–442) with simple basal sclerite connected to distal (main) sclerite, sperm duct opening at basis of distal sclerite; distal sclerite with sharp retrolateral ridge and distinctive set of prolateral apophyses and ridges.

LEGS. Femur 1 with single row of ~40 ventral spines; without curved hairs; few vertical hairs; retrolateral trichobothrium of tibia 1 at 3.5%; prolateral trichobothrium absent on tibia 1, present on other leg tibiae; tarsi with indistinct platelets rather than regular pseudosegments.

Male (variation)

Tibia 1 in 16 males (incl. holotype): 9.9–13.1 (mean 11.3). Smaller males with fewer spines on femur 1 (~10–20). Abdomen often also with white marks. Ventral parallel marks on abdomen variably fused or separate.

Female

In general similar to male (Fig. 395) but without spines on legs, with small and poorly visible stridulatory files on chelicerae, and with stridulatory organ consisting of pair of weakly sclerotized but distinct processes posteriorly on carapace and pair of distinct light brown plates anteriorly on abdomen. Tibia 1 in 17 females: 7.1–11.7 (mean 9.8). Epigynum as in Figs 445–446, main epigynal plate semicircular to triangular, weakly protruding, only posteriorly laterally heavily sclerotized; with pair of shallow furrows ~390 µm apart; internal sclerotized arcs visible in uncleared specimens; posterior plate short but wide. Internal genitalia (Figs 443–444, 447–449) with large oval pore plates converging anteriorly, dorsal arc strong but simple, ventral arc with median modification of unknown function.

Natural history

This species was often very abundant, both in villages (in and on abandoned buildings; in fairly exposed webs at the basis of banana and other plants) and in natural environments (under rocks, in small cavities). At Mukal Cave, it was only found outside the cave, while the cave itself was occupied by C. moqal sp. nov. Between Sur and Al Kamil, the species was abundant in a palm garden surrounded by large rocks; while large specimens were mostly restricted to the rocks, smaller specimens were also found on the palms, even among leaves of young palms, at least up to 1.5 m above the ground.

Distribution

Known from several localities in the Eastern Hajars of NE Oman (Fig. 352).