Pescennina Simon 1903
Creators: name: Platnick, Norman I.
name: Dupérré, Nadine
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Oonopidae
Pescennina

description: Pescennina Simon   
 Pescennina Simon, 1903a: 32 (type species by monotypy P. epularis Simon).   
 Marsupopaea Cooke, 1972: 91 (type species by original designation M. sturmi Cooke). NEW SYNONYMY.   
DIAGNOSIS: Males of this genus can easily be recognized by the terminally situated, distally coiled embolus (figs. 236, 237), which is strongly twisted at its base, makes a wide turn over the dorsal surface of the cymbium, and rests in the deeply excavated anterior portion of the sternum (figs. 3, 103, 232); females have distinctively coiled anterior ducts that apparently accommodate the embolar coils (figs. 14, 37) and a posterior receptaculum that is marked with circular ridges and protected by the posterior apodemes (figs. 15, 153).  
 DESCRIPTION: Total length of males 1.4–2.4, of females 1.5–2.6; carapace yellow-brown to brown, sometimes with dark markings, sternum and mouthparts yellow-brown to brown, sternum sometimes with dark markings; abdomen white, often with dorsal and lateral dark markings; legs usually yellow, some segments often patterned. Cephalothorax: Carapace usually elongate oval in dorsal view (figs. 98, 138), anteriorly narrowed to 0.49 times its maximum width or less (but ovoid and wider in front in P. cupida and P. orellana), pars cephalica slightly elevated in lateral view (figs. 99, 139), pars thoracica with angular posterolateral corners (figs. 101, 141), without depressions, posterolateral edge without pits, posterior margin not bulging below posterior rim, anterolateral corners with slightly sclerotized triangular projections, posterolateral surface without spikes, fovea absent, without radiating rows of pits; lateral margin straight, rebordered (figs. 102, 142), with sharply pointed denticles; plumose setae near posterior margin of pars thoracica absent; nonmarginal pars cephalica setae dark, needlelike, scattered; nonmarginal pars thoracica setae and marginal setae dark, needlelike. Clypeus margin slightly rebordered, straight in front view, sloping forward in lateral view, high (figs. 100, 140), ALE separated from edge of carapace by their radius or more, median projection absent; setae dark, needlelike. Chilum absent. Eyes six, well developed, ALE largest, ALE oval, PME usually circular (but squared in P. cupida and P. orellana, fig. 188), PLE oval; posterior eye row procurved from front, usually straight from above (but recurved in P. cupida and P. orellana, fig. 186); ALE separation variable, ALE-PLE separated by less than ALE radius, PME separated by less than their radius, PME-PLE separation variable. Sternum longer than wide, uniform, distinctly fused to carapace only in P. cupida and P. orellana, median concavity absent, without radial furrows between coxae I–II, II–III, III–IV, radial furrow opposite coxae III absent, without pits, microsculpture present everywhere, but front, sickle-shaped structures absent, anterior margin of males with large, deep, medially narrowed transverse groove (fig. 103), groove of females smaller, shallower (fig. 143); posterior margin extending posteriorly beyond anterior edges of coxae IV as single extension (fig. 103), anterior corner unmodified, lateral margin with infracoxal grooves bearing anterior and posterior openings (fig. 143), distance between coxae approximately equal, extensions of precoxal triangles absent, lateral margins with indented extensions between coxae, without posterior hump; hair tufts absent; setae sparse, dark, needlelike, densest laterally, originating from surface. Chelicerae straight (figs. 104, 105, 144, 145), anterior face unmodified; without teeth on either promargin or retromargin; fang without toothlike projections, directed medially, shape normal, without prominent basal process, tip unmodified; setae dark, needlelike, evenly scattered; paturon inner margin with short interdigitating setae, distal region abruptly narrowed, posterior surface unmodified, promargin unmodified, inner margin unmodified, laminate groove absent. Labium triangular, fused to sternum, anterior margin indented at middle (figs. 106, 146), same as sternum in sclerotization; with six or more setae on anterior margin, subdistal portion with unmodified setae. Endites distally not excavated, serrula present in single row (figs. 108, 109, 147, 148), anteromedian tip with stout projection in males (fig. 107), posteromedian part unmodified, same as sternum in sclerotization. Female palp (figs. 149, 150) without claw; spines absent; tarsus unmodified, patella without prolateral row of ridges, tibia with three trichobothria (fig. 151). Abdomen: Without long posterior extension, rounded posteriorly, interscutal membrane rows of small sclerotized platelets absent. Booklung covers large, ovoid, without setae, anterolateral edge unmodified. Posterior spiracles connected by groove. Pedicel with scutopedicel region unmodified, plumose hairs absent, matted setae on anterior ventral abdomen absent, cuticular outgrowths near pedicel absent. Pedicel tube of males medium, ribbed, scutum extending far dorsal of pedicel, of females short, not ribbed, not extending far dorsal of pedicel (figs. 137, 139). Ventral pedicel sclerite of males fused to sternum, usually separate in females (except in P. cupida and P. orellana), but sometimes separated from sternum by only tiny, inconspicuous sliver of unsclerotized cuticle or with no trace of that sliver visible (in presumably contracted specimens). Dorsal scutum absent in females but present in males, where strongly sclerotized, not fused to epigastric scutum, covering more than ¾ of abdominal length, smooth, without anterior denticles. Epigastric scutum surrounding pedicel, strongly sclerotized in males, weakly sclerotized, not extending as far above pedicel in females, not protruding, small lateral sclerites absent, without lateral joints in females. Postepigastric scutum of male strongly sclerotized, long, almost rectangular, occupying most of space between epigastric furrow and spinnerets, fused to epigastric scutum, but in females only weakly sclerotized, short, confined to epigastric area, not fused to epigastric scutum (fig. 152); in both sexes anterior margin unmodified, with short posteriorly directed lateral apodemes. Interscutal membrane with setae. Spinneret scutum present, incomplete ring, with fringe of long setae. Supraanal scutum absent. Dorsum setae dark, needlelike; epigastric area setae uniform, dark, needlelike; postepigastric area setae dark, needlelike. Dense patch of setae anterior to spinnerets absent. Colulus absent. Spinnerets (scanned only in P. arborea, figs. 110, 154); ALS with single major ampullate gland spigot and two piriform gland spigots in males (fig. 111), three in females (fig. 155); PMS with single spigot in males (fig. 112), four spigots in females (fig. 156); PLS with three spigots in males (fig. 113), five in females (fig. 157). Male epigastric region with sperm pore large, oval, rebordered, situated in front of anterior spiracles (fig. 124); furrow without Ω-shaped insertions, without setae. 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 absent, ventral scopula absent, metatarsi I and II mesoapical comb absent, metatarsi III and IV weak ventral scopula absent. Leg spines absent. Tarsal proclaws and retroclaws outer faces with few large teeth (figs. 118, 162), inner faces striated (fig. 163), with numerous small teeth, those on legs I–III with teeth of inner margin coalesced at tip (figs. 114–117, 158–161); inferior claws absent. Trichobothrial bases rounded, aperture internal texture not gratelike, hood covered by numerous low, closely spaced ridges (fig. 169). Tarsal organs of legs I, II, and palp apparently with three sensillae (figs. 119, 120, 123, 164, 165, 168), of legs III, IV with two sensillae (figs. 121, 122, 166, 167). Genitalia: Male palp of normal size, not strongly sclerotized, right and left palps symmetrical; trochanter normal size, unmodified; femur two or more times as long as trochanter, without posteriorly rounded lateral dilation, attached to patella basally (except in P. cupida); patella shorter than femur, not expanded (except in P. cupida, where larger than femur), without prolateral row of ridges, setae unmodified; tibia short, with three dorsal trichobothria (fig. 127); cymbium ovoid in dorsal view, completely fused with bulb, no seam visible, not extending beyond distal tip of bulb, plumose setae absent, without stout setae, without distal patch of setae; bulb 1–1.5 times as long as cymbium, stout, tapering apically; embolus light, prolateral excavation absent; typically with distal coils (figs. 125, 126, 128, 129), embolar base typically with elaborate prongs (figs. 130–136). Female genitalia with anterior looping or coiled ducts, often with transverse duct portion; posterior receptaculum surrounded by apodemes, surface with circular ridges (fig. 153).   
DISTRIBUTION: Northern Mexico to southern Brazil.  
 SYNONYMY: We hypothesize that the name Marsupopaea refers to the males of Pescennina.
description: Published as part of Platnick, Norman I. & Dupérré, Nadine, 2011, The Goblin Spider Genus Pescennina (Araneae, Oonopidae), pp. 1-64 in American Museum Novitates 2011 (3716) on pages 5-8, DOI: 10.1206/3712.2, http://zenodo.org/record/10108999