Raveniola Zonstein, 1987

Raveniola Zonstein, 1987: 1014 .

Raveniola – Zonstein & Marusik 2012: 74. — Li & Zonstein 2015: 3.

Type species

Brachythele virgata Simon, 1891, by original designation.

Emended diagnosis

Raveniola and Sinopesa share two (sometimes three) retroventral megaspines located sequentially on tibia I in males (the unique position among male nemesiids) and the paired spermathecae in females, each carrying two individual receptacular heads; within these taxa the PMS are reduced in size (lost entirely in some species) and the maxillary serrula and preening combs are absent. Raveniola is currently known to differ from Sinopesa by a noticeably longer and denser leg scopula (vs a short and rare scopula in Sinopesa), and by a developed leg and carapace setation. The male palpal organ is moderate in size in Raveniola but appears to be enlarged (with respect to the entire male palp) in Sinopesa .

Morphological peculiarities of Western Asian congeners

HABITUS (Figs 43–58). The studied spiders are mostly small or medium-sized nemesiids with a carapace length of 2–10 mm.

PROSOMA. Carapace broad-oval and hirsute, with cephalic part slightly to noticeably higher than thoracic part. Eye tubercle predominantly low in males and females (best developed in Raveniola hyrcanica). Cheliceral mound and rastellum absent (see Fig. 1). In males chelicerae with a small, softened, pale area probably corresponding to a vestigial or poorly-developed intercheliceral male tumescence and located in the well-developed cavity on the ventral cheliceral surface (Figs 59–60). Sternal sigilla medium-sized to small, broad-oval, submarginal (see Figs 62–64). Maxillae with few to numerous maxillary cuspules confined to probasal edge. Serrula absent, but cuticle near the anterior maxillary edge has remnants of scales (Figs 2–3).

STRUCTURES OF LEGS I–IV. Male tibia and metatarsus I as shown in Figs 129–144. Leg scopula varies from dense and moderately long to thin and short; distal on metatarsi I–II, generally entire on tarsus I, mostly divided on tarsus II; females also with entire scopula on palpal tarsus. Tarsal organ low, domed, with weak to sharp concentric ridges (Figs 7–12). Trichobothrial bases corrugiform (Figs 13–18). Female palp with tarsal claw dentate on promargin (Fig. 19). Paired tarsal claws of legs I–IV biserially dentate, unpaired claw always present, moderately small and bare (Figs 20–24).

MALE PALP. Tibia of moderate to short length, spinose. Cymbium moderately short, with or without spines (Figs 149–160). Male palpal bulb pyriform, inserted submedially. Embolus short to moderately long, tapering or spiraled, with or without keels and ridges (Figs 4, 171–197).

SPERMATHECAE. Two wide or narrow spermathecae, each with two receptacles (Figs 198–212).

SPINNERETS. Two pairs of spinnerets (PMS always present). PMS small but with a few fully functional spigots confined to the apex (Figs 25–30). PLS with spigots confined to ventral surface of segments (Figs 33–36) and with apical segment triangular to digitiform (Figs 31–32, 65–67).

Species included

Raveniola currently comprises 37 species, including the new species described here; 16 of them occur in Western Asia: R. adjarica sp. nov., R. anadolu sp. nov., R. arthuri Kunt & Yağmur, 2010, R. birecikensis sp. nov., R. dunini sp. nov., R. hyrcanica Dunin, 1988, R. marusiki sp. nov., R. mazandaranica Marusik, Zamani & Mirshamsi, 2014, R. micropa (Ausserer, 1871), R. nana sp. nov., R. niedermeyeri (Brignoli, 1972), R. pontica (Spassky, 1937), R. sinani sp. nov., R. turcica sp. nov., R. vonwicki Zonstein, 2000 and R. zaitzevi (Charitonov, 1948) .

Species grouping

To enhance identifications, the species treated here are assigned to three species groups.These assignments are preliminary, because males and females in some species are unknown, and they are not based on a phylogenetic grouping, though some of the groups may indeed reflect phylogenetic relationships. The similarity in external morphology in all females of Western Asian Raveniola necessitates their assignment both throughout the species and the species groups being entirely based on the structure of the spermathecae.

Distribution and ecology

Within Western Asia, representatives of Raveniola are distributed from the western part of Anatolia (Turkey: Bursa) through the Caucasus mountain region to the Alborz and Khorasan Mts, Iran. All species with known habitats were found in different types of piedmont and mountainous deciduous broad-leaved forests, and at least some of them may inhabit the higher coniferous forest belt ( R. adjarica sp. nov.) or even subalpine grasslands ( R. pontica); some species (like R. dunini sp. nov.) are also found in the open forest biotopes at low altitudes. In most species, females use cavities under rocks to build primitive burrow-like dwellings lacking any silk-lining. However, females of R. hyrcanica, unlike other congeners, dig very simple open burrows, also without silk-lining, in the forest floor.

Key to the Western Asian species groups of Raveniola

Males

1. Palpal tibia subcylindrical, without bare preapical area, low mound and sensilla (as in Figs 171– 188) …………………………………………………………………………………………………2

– Palpal tibia dilated subapically, bearing retrolateral hump and bare retroventral-distal area with low mound and sensilla (as in Figs 189–197) ………………………………… niedermeyeri group

2. Embolus always keeled; embolic keel laterally directed (Figs 171–179) ……… hyrcanica group

– Embolus with or without keel; embolic keel, if present, running parallel to embolus (Figs 180– 188) ………………………………………………………………………………… micropa group

Females

1. Bases of spermathecae relatively narrow or moderately wide (Figs 204–212) …………………2

– Bases of spermathecae very wide (Figs 198–203) ……………………………… hyrcanica group

2. Bases of spermathecae always moderately wide; median and lateral receptacles subequal in shape and size (Figs 204–207) …………………………………………………………… micropa group

– Bases of spermathecae generally relatively narrow (Figs 210–212); median and lateral receptacles different in shape and size (Figs 208–209) ………………………………… niedermeyeri group