Platylampona, PLATNICK, 2004

PLATNICK, NORMAN I., 2004, On a Third Group of Flattened Ground Spiders from Australia (Araneae, Lamponidae), American Museum Novitates 3462 (1), pp. 1-8 : 4-6

Platylampona , new genus

TYPE SPECIES: Platylampona mazeppa , new species .

ETYMOLOGY: The generic name refers to the general appearance of these flattened lamponids, and is feminine in gender.

DIAGNOSIS: In the existing key to lamponine genera ( Platnick, 2000: 14), specimens of Platylampona will key out to Lamponova Platnick because the ventral surface of metatarsi and tarsi I and II does have a divided (if weak) scopula, the sternal surface is smooth with circular punctations rather than rugose, and the female epigynum lacks an anterior hood (males of Lamponova remain unknown). The greatly flattened habitus (figs. 1–3) and sinuous lateral margins of the carapace (fig. 1) immediately separate the genus from Lamponova and all other lamponids. In having the chilum fused to the anterior margin of the carapace, producing a medial prolongation of that margin, Platylampona specimens resemble those of Lamponega and Lamponicta ; they can be distinguished from the former by the flattened (rather than greatly elevated) sternum and from the latter by the presence of a retrolateral tibial apophysis on the male palp and the absence of a posterior spermathecal bulb in females. As indicated above, specimens might be confused with either trochanteriids (but lack a distal ring on the anterior lateral spinnerets) or hemicloeine gnaphosids (but have small, rather than enlarged, piriform gland spigots on the anterior lateral spinnerets).

DESCRIPTION: Small spiders, total length 2.9–3.8. Carapace dark red, greatly flattened, tuberculate, coated with long setae originating from bases of tubercles, tubercles protruding from sinuous lateral margin (fig. 1); thoracic groove short, almost obsolete. Eight eyes in two rows, eyes large, subequal in size; anterior medians circular, dark, other eyes light, laterals oval, posterior medians irregularly rectangular, flattened; from above, both eye rows slightly procurved, from front, anterior row slightly procurved, posterior row strongly procurved; anterior medians separated by almost their diameter, slightly closer to anterior laterals; posterior medians separated by almost their diameter, separated by more than their diameter from posterior laterals; anterior and posterior laterals separated by more than their diameter; median ocular quadrangle about as wide in front as in back, slightly longer than wide. Chelicerae, sternum, and mouthparts dark red; chilum apparently fused to carapace, which is prolonged at midline; second, short, posterior chilum (extremely narrow sclerite separating bases of chelicerae posteriorly) present; chelicerae with deeply excavated ridge opposite carapace margin, followed distally by distinct lateral boss and large median boss occupying most of paturon width, promargin with series of short setae originating in line along base of fang, with long, thick, modified seta originating closest to fang; promargin with teeth obsolete, represented by fused ridge, retromargin without teeth; cheliceral gland openings not scanned. Labium elongated, truncate anteriorly and posteriorly, distinctly depressed medially; anterior surface not scanned. Endites obliquely depressed, with sharply demarcated, deep groove along margin near labium; serrula long, with single row of teeth; anterior surface not scanned. Sternum flattened, with inclined sides, fused to epimeric sclerites so that coxae originate from foramina completely enclosed by sclerotized cuticle (except between legs III and IV of females, where the fusion is not entire, with tiny strip of unsclerotized cuticle remaining between sternum and epimeric sclerite); surface smooth, with circular punctations. Epimeric sclerites not fused with carapace. Pedicel elongated, composed of two small, flat dorsal sclerites and rounded sclerite covering venter and sides, rounded sclerite with slight median longitudinal keel, without anterior protrusion extending toward sternum.

Anterior edge of abdomen in males with rectangular dorsal scutum extending to almost half of abdominal length; dorsal scutum anteriorly separated from epigastric scutum only by narrow strip of unsclerotized cuticle; females without dorsal scutum; cuticle with long dark setae; epigastric scutum accompanied posterolaterally by pair of oval, deeply invaginated sclerites bearing clearly elevated anterior rim; anterior edge of oval sclerites fitting under epigastric scutum; sclerites of male expanded into rectangular plates occupying about one­third of postepigastric portion of abdominal venter; colulus represented by transverse row of setae posterior of tiny transverse sclerite presumably marking position of small posterior spiracle. Anterior lateral spinnerets tubular, separated by roughly their diameter, cuticle representing distal, second spinneret segment restricted to semicircle surrounding major ampullate gland spigots (piriform gland spigots surrounded only by soft cuticle, apparently only one or two present); posterior median spinnerets small, tubular, without anteriorly expanded tips; posterior lateral spinnerets two­segmented, spigots unscanned.

Legs spineless, laterigrade; most surfaces with long, dark setae; anterior coxae with protuberant posterolateral corners; coxae tuberculate, coxae IV much longer than others; trochanters unnotched; anterior metatarsi and tarsi with weak but distinct, divided scopulae composed of short, thickened, bent setae; posterior metatarsi with thick, dark, distal preening brushes (stronger on leg III than IV); posterior tarsi with weak, entire scopulae; tarsi with two finely dentate claws, claw tufts composed of lateral pads of closely appressed setae; trichobothria present on tibiae, metatarsi, and tarsi, in 2–3 irregular rows, bases unscanned; tarsal organ unscanned. Female palpal tarsus without spines, with tiny claw.

Male palp with retrolateral tibial apophysis accompanied by strong macroseta, cymbial surface with retrobasal excavation opposite retrolateral tibial apophysis; tegulum expand­ ed, extending beyond posterior rim of tarsus; embolus laterally situated, inset into membranous conductor; median apophysis absent. Epigynum with v­shaped median septum; spermathecae on short stalks.

Platylampona mazeppa , new species

Figures 1–8

TYPE: Male holotype taken by pyrethrum sampling of gidgee (an indigenous group of Acacia species ) trunks at an elevation of 240 m at the north end of Mazeppa National Park , 22 ° 14 ̍ S, 147 ° 15 ̍ E, Queensland (Mar. 27, 2001; G. Monteith), deposited in QMB ( S55138 ) .

ETYMOLOGY: The specific name is a noun in apposition taken from the type locality.

DIAGNOSIS: With the characters of the genus and genitalia as in figures 4–8.

MALE (holotype): Total length 2.9. Dorsal and postepigastric abdominal scuta light orange, unsclerotized portion of abdominal dorsum mottled gray, venter unmarked; legs light orange, unmarked, anteriors darkest. Palpal femur with distinct ventral enlargement at about one­third its length; patella dorsoventrally flattened, laterally widened; tibia short, retrolateral portion about as long as retrolateral tibial apophysis, dorsally and prolaterally prolonged, with one or two thick macrosetae on prolongation; palpal tegulum enlarged, protruding ventrally beyond base of cymbium, embolus situated prolaterally, apically extended into fine point (figs. 4–6).

FEMALE (from type locality): Total length 3.8. Coloration as in male (but without abdominal scuta). Epigynum with anterior margins and median septum forming m­shaped ridge, openings apparently at anterolateral corners of median septum; spermathecae oval, on short stalks (figs. 7, 8).

VARIATION: The male palpal tibia can have either one strong dorsal macroseta (as shown in figs. 4, 6) or two, but the distinction does not seem to be taxonomically significant, as the number can differ on the left and right palps of a single specimen.

OTHER MATERIAL EXAMINED: AUSTRA­ LIA: New South Wales: Atholwood Loop Road, 500 m N of road at point opposite Retford Springs, Severn State Forest , 29 ° 04 ̍ 28 ̎ S, 151 ° 00 ̍ 53 ̎ E, Nov. 22–Dec. 13, 2001, pitfall (L. Wilkie, H. Smith, AMS KS81891 ), 13; 16 km S Texas (Queensland), 29 ° 00 ̍ S, 151 ° 09 ̍ E, Nov. 24, 1983 (D. Rentz, M. Harvey, ANIC), 2♀ . Queensland: 3 km NW Langlo Crossing , 26 ° 07 ̍ S, 145 ° 39 ̍ E, May 4, 2001, pyrethrum, gidgee (G. Monteith, QMB), 1♀ ; S end, Mazeppa National Park , 22 ° 16 ̍ S, 147 ° 16 ̍ E, Dec. 18, 2000 – Mar. 26, 2001, elev. 240 m, flight intercept trap, brigalow (D. Cook, G. Monteith, QMB), 1♀ ; site 3, Mazeppa National Park, 22 ° 16 ̍ S, 147 ° 17 ̍ E, Mar. 27, 2001, elev. 240 m, pyrethrum, gidgee trunks (G. Monteith, QMB S55141 ), 13; on road 7 km NNE Mount Bluffkin , 22 ° 36 ̍ S, 149 ° 14 ̍ E, June 2, 2002, elev. 160 m, pyrethrum, brigalow (G. Monteith, QMB S52782 ), 13; 5 km SW Mount Robert, 21 ° 24 ̍ S, 148 ° 27 ̍ E, Mar. 26, 2001, elev. 300 m, pyrethrum, tree trunks and logs, brigalow (G. Monteith, QMB S55136 ), 13 .

DISTRIBUTION: Known only from central and southern Queensland and northeastern New South Wales.

Figures

Figs. 1–3. Platylampona mazeppa, new species, male. 1. Dorsal view. 2. Ventral view. 3. Lateral view of cephalothorax and abdomen.

Figs. 4–8. Platylampona mazeppa, new species. 4. Left male palp, prolateral view. 5. Same, ventral view. 6. Same, retrolateral view. 7. Epigynum, ventral view. 8. Same, dorsal view.