Bidysderina, Platnick & Dupérré & Berniker & Bonaldo, 2013

Platnick, Norman I., Dupérré, Nadine, Berniker, Lily & Bonaldo, Alexandre B., 2013, The Goblin Spider Genera Prodysderina, Aschnaoonops, And Bidysderina (Araneae, Oonopidae), Bulletin of the American Museum of Natural History 2013 (373), pp. 1-102 : 89-91

Bidysderina , new genus

TYPE SPECIES: Bidysderina perdido , new species.

ETYMOLOGY: The generic name refers to the bipartite embolus and the similarities to the genus Dysderina , and is feminine in gender.

DIAGNOSIS: Members of this genus resemble those of Prodysderina and Aschnaoonops in sternal and spiracular characters, but can easily be distinguished by the deeply bifid embolar structure (figs. 627, 660), the distinctively modified tips of the male endites (fig. 595), and the small but distinct female genitalic atrium (figs. 622, 644). The almost fully bifid embolar structure suggests that, despite the sternal similarities to Prodysderina and Aschnaoonops , this genus may actually be more closely related to Dysderina and some undescribed genera, the members of which seem to have a fully separate embolus and conductor.

DESCRIPTION: Total length of male 1.6– 2.1, of females 2.3–3.1. Carapace, sternum, mouthparts, abdominal scuta, legs orangebrown, without pattern; abdomen soft portions white, without pattern. Cephalothorax: Carapace broadly oval in dorsal view (fig. 590), anteriorly narrowed to 0.49 times its maximum width or less, pars cephalica strongly elevated in lateral view (fig. 591), anterolateral corners with strongly sclerotized, triangular extension, pars thoracica with rounded posterolateral corners, without depressions or radiating rows of pits, posterolateral edge without pits, posterior margin not bulging below posterior rim, posterolateral surface without spikes; surface of elevated portion of pars cephalica granulate, sides granulate; fovea absent, lateral margin straight, rebordered, with blunt denticles not bearing setae (fig. 591); plumose setae near posterior margin of pars thoracica absent; marginal, nonmarginal pars cephalica, pars thoracica setae light, needlelike, scattered. Clypeus margin strongly rebordered, sinuous in front view, vertical in lateral view, high, ALE separated from edge of carapace by their radius or more, median projection present, formed by fused small, triangular chilum (fig. 592); setae light, needlelike. Eyes six, well developed, ALE largest, oval, PME squared, PLE oval; posterior eye row recurved from above, procurved from front; ALE separated by less or more than their radius, ALE-PLE separated by less than ALE radius, PME touching throughout most of their length, PLE-PME separated by less than PME radius. Sternum (fig. 600) wider than long, not fused to carapace, surface coarsely reticulate, microsculpture present everywhere but front, without transverse ridges or pits, median concavity and hair tufts absent, with radial furrows between coxae I–II, II–III, III–IV, furrows with rows of small pits, radial furrow opposite coxae III absent, sickle-shaped structures absent, anterior margin with continuous transverse groove, posterior margin not extending posteriorly of coxae IV but with posterior hump, anterior corners excavated, lateral margins with infracoxal grooves bearing anterior, posterior openings, distance between coxae approximately equal, extensions of precoxal triangles absent, lateral margins with bridges to coxae; setae sparse, dark, needlelike, densest laterally, originating from surface, posterior and lateral margins with conspicuous, tuberculate setal bases. Chelicerae slightly divergent, anterior face with slight swelling (fig. 593); teeth scanned only in male of B. perdido , usually with one large tooth on promargin, one smaller tooth on retromargin, but male of B. perdido with promarginal tooth enlarged into distinct lobe bearing numerous tiny projections on retrolateral surface (fig. 594); fangs without toothlike projections, directed medially, shape normal, without prominent basal process, tip unmodified; setae dark, needlelike, densest medially; paturon inner margin with scattered setae, distal region, posterior surface unmodified, promargin with row of flattened setae, inner margin unmodified, laminate groove absent. Labium (fig. 595) triangular, not fused to sternum, anterior margin not indented at middle, same as sternum in sclerotization; with six or more setae on anterior margin, subdistal portion with unmodified setae. Endites same as sternum in sclerotization, anterior portion modified in males with distally excavated, ventrally with small, sharply pointed, triangular apical projection, dorsally with larger, much more heavily sclerotized, triangular projection, dorsal projection directed ventrally, medially (fig. 595), posterior portion unmodified; serrula absent in males (scanned only in male of B. perdido , fig. 596), apparently present as single row of teeth in females (not scanned, uncertain); labrum with rounded projection. Female palp without claw or spines; patella without prolateral row of ridges, tarsus elongate. Abdomen: Ovoid, without long posterior extension, rounded posteriorly, interscutal membrane without rows of small sclerotized platelets. Booklung covers large, ovoid, without setae, anterolateral edge unmodified; posterior spiracles connected by groove, groove continued beyond spiracles almost to lateral edge of postepigastric scutum. Pedicel tube medium, ribbed, scutopedicel region unmodified, scutum extending far dorsal of pedicel, plumose hairs, matted setae on anterior ventral abdomen in pedicel area, cuticular outgrowths near pedicel all absent. Dorsal scutum strongly sclerotized, in males covering full length of abdomen, no soft tissue visible from above, not fused to epigastric scutum around midline, in females smaller, occupying more than half of abdomen width, fused to epigastric scutum; middle surface smooth, sides smooth, anterior half without projecting denticles. Epigastric scutum strongly sclerotized, surrounding pedicel, not protruding, small lateral sclerites absent, without lateral joints in females. Postepigastric scutum strongly sclerotized, in males covering nearly full length of abdomen, fused to epigastric scutum (in females much shorter, not fused to epigastric scutum); anterior margin unmodified, with short posteriorly directed lateral apodemes. Spinneret scutum present, incomplete ring, with fringe of long setae; supraanal scutum absent. Abdominal setae dark, needlelike, epigastric area setae not basally thickened; dense patch of setae anterior to spinnerets absent, interscutal membrane with setae. Colulus present, tiny, with pair of setae. Anterior lateral spinnerets bisegmented, basal segment without oblique membranous strip, posterior medians unisegmented, posterior laterals bisegmented (fig. 601); spigots scanned only in male of B. perdido , anterior laterals with single major ampullate gland spigot and four piriform gland spigots (fig. 602); posterior medians with four spigots (three with convex bases, presumably minor ampullate gland spigots, one with concave base, presumably aciniform gland spigot, fig. 603); posterior laterals with five spigots (four with convex bases, one with concave base, fig. 604). Legs: Femur IV not thickened, same size as femora I–III, patella plus tibia I shorter than carapace, tibia I unmodified, tibia IV specialized hairs on ventral apex, ventral scopula absent, metatarsi I, II mesoapical comb absent, metatarsi III, IV ventral scopula absent. Leg spines present on anterior femora, tibiae, metatarsi; femoral spines strong, tibial and metatarsal spines long, spines absent on posterior legs. Tarsi without inferior claw. Superior claws (scanned only in male of B. perdido ) with single row of five or six teeth set on inner margin, most distal tooth greatly elongated on leg IV (figs. 606–613). Trichobothrial base with numerous parallel ridges (fig. 614). Tarsal organs with three receptors on legs I, II (figs. 615, 616), two on legs III, IV, palps (figs. 617, 618, 619). Genitalia: Male epigastric region with sperm pore small, narrow, slitlike, situated between anterior and posterior spiracles, rebordered (fig. 605); furrow without Ω- shaped insertions, without specialized setae. Male palp of normal size, not strongly sclerotized, right and left palps symmetrical, proximal segments pale orange, cymbium, bulb yellow; embolus dark, without prolateral excavation; trochanter of normal size, unmodified; femur of normal size, two or more times as long as trochanter, without posteriorly rounded lateral dilation, attaching to patella basally; patella shorter than femur, not enlarged, without prolateral row of ridges, setae unmodified; tibia with three trichobothria (fig. 599); cymbium (figs. 597, 598) ovoid in dorsal view, completely fused with bulb, no seam visible, extending beyond distal tip of bulb, plumose setae, stout setae, distal patch of setae all absent; bulb shorter than cymbium, slender, elongated. Distal elements deeply bifid, with embolus situated retrolateral to conductor, conductor sometimes also bifid (fig. 639). Female genitalia externally with short, wide atrium (fig. 622), internally with pair of slight to pronounced protrusions situated near anterior spiracles (presumably serving as muscle attachments), sclerotized anterior genitalic process, often accompanied by transverse basal sclerite visible through cuticle of atrium (fig. 622).

DISTRIBUTION: Known only from Napo province, Ecuador.

KEY TO SPECIES

1. Males.......................... 2

– Females (unknown in B. cayambe )..... 6

2. Conductor bifid (as in figs. 637, 639)... 3

– Conductor entire.................. 5

3. Conductor long, only distal half bifid (figs. 670, 671)........................ cayambe

– Conductor shorter, bifid nearly to base... 4

4. Retrolateral prong of conductor relatively long, extending almost to embolus (fig. 649)........................ niarchos

– Retrolateral prong of conductor relatively short (fig. 638)................ bifida

5. Embolus relatively narrow (fig. 627).... perdido

– Embolus relatively wide (fig. 660)... wagra

6. Tip of anterior genitalic process greatly expanded (fig. 652)........... niarchos

– Tip of anterior genitalic process much smaller .......................... 7

7. Tip of anterior genitalic process relatively wide (fig. 641)................. bifida

– Tip of anterior genitalic process narrower (figs. 630, 663)................... 8

8. Stem of anterior genitalic process relatively short, wide (fig. 630)........... perdido

– Stem of anterior genitalic process relatively long, narrow (fig. 663)........... wagra