Morebilus blackdown, PLATNICK, 2002

PLATNICK, NORMAN I., 2002, A Revision Of The Australasian Ground Spiders Of The Families Ammoxenidae, Cithaeronidae, Gallieniellidae, And Trochanteriidae (Araneae: Gnaphosoidea), Bulletin of the American Museum of Natural History 2002 (271), pp. 1-1 : 1-

publication ID

https://doi.org/ 10.1206/0003-0090(2002)271<0001:AROTAG>2.0.CO;2

persistent identifier

https://treatment.plazi.org/id/03EAE52A-FF32-A6CF-8247-21ECD8AF48BF

treatment provided by

Felipe

scientific name

Morebilus blackdown
status

sp. nov.

Morebilus blackdown , new species Figures 395, 396 View Figs ; Map 31 View Map 31

TYPE: Female holotype from Blackdown Tableland , SW Rockhampton, 23 ° 48 ̍ S, 149 ° 08 ̍ E, Queensland (Oct. 5–6, 1982; A. Rozefelds), deposited in QMB ( S28485 View Materials ) .

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

DIAGNOSIS: Females resemble those of M. tambo , but have a posteriorly widened epigynal atrium containing a distinct, longitudinal septum (fig. 395).

MALE: Unknown.

FEMALE: Total length 11. Coloration as in M. tambo . Leg spination: tibiae II v3­2­2; metatarsi II v2­1p­0. Epigynum with pair of semicircular lateral margins and long, narrow atrium extending almost to posterior edge of structure, atrium divided by elevated septum (fig. 395); spermathecae anteriorly soft, inflated, with anterolaterally directed heads (fig. 396).

OTHER MATERIAL EXAMINED: None.

DISTRIBUTION: Known only from mid­eastern Queensland (map 31).

Longrita , new genus

TYPE SPECIES: Hemicloea insidiosa Simon.

ETYMOLOGY: The generic name is an arbitrary combination of letters, considered feminine in gender.

DIAGNOSIS: Members of this genus resemble those of Morebilus in having smooth tarsal claws and a distinct (if somewhat less pronounced) anterior lip on the sternum, but can easily be distinguished by their bizarre genitalia. Males have the retrolateral tibial apophysis enormously elongated, extending almost to the tip of the palpal cymbium (fig. 408). Females show a presumably concomitant elongation of the epigynum, with an anterior hood situated just behind the pedicel, and separated from the remainder of the epigynum by easily extensible cuticle (fig. 409).

DESCRIPTION: Large spiders, total length of males 9–17, of females 10–20. Carapace flattened, without tubercles, with rebordered lateral margins, evenly coated with scattered, dark, stiff, erect setae; few longer, erect, dark setae present (pair at rear of pars cephalica, one opposite each coxa, few at each anterolateral corner and few crossing at midline of clypeus); thoracic groove long, Y­shaped, indistinct, wider anteriorly than posteriorly; cephalic groove pronounced, accompanied by three additional intercoxal grooves on each side. Eight eyes in two rows, anterior medians largest, circular, dark, posterior medians smallest, circular, lenses slightly flattened but canoe­shaped tapetum apparently still present, laterals subequal, almost as large as anterior medians, oval; from above, anterior eye row slightly procurved, posterior row slightly recurved, from front, both eye rows almost straight; anterior medians separated by more than their diameter, by almost twice their diameter from anterior laterals; posterior medians separated by about five times their diameter, about as far from posterior laterals; anterior and posterior laterals separated by more than their diameter; median ocular quadrangle much wider in back than in front or than long. Chelicerae porrect, divergent, with distinct oblique groove just below clypeus; anterior surface with stiff setae along inner margins; chilum very wide, triangular, unipartite but with small area of unsclerotized cuticle along ventral one­third of midline area, accompanied by second, elongated, posterior chilum (narrow, I­shaped sclerite separating bases of chelicerae posteriorly); chelicerae with distinct lateral boss, promargin with series of long setae originating in line along base of fang, those nearest base of fang unmodified; promargin with three teeth, proximal tooth smaller than others, distalmost tooth widely separated from other two, retromargin with two widely separated teeth; presumptive cheliceral gland openings on distinct mound, surrounded by concentric ridges, situated proximal to basal retromarginal tooth. Labium rectangular, flat, posterior one­quarter narrowed, anterior margin rounded at sides. Endites long, divergent, with oblique depression restricted to their median edge; serrula absent (fig. 156), long, oval, sieve plate conspicuous under light microscopy; anteromedian edges and apex bearing wide patch of long, stiff, dark setae. Sternum flat, with rebordered, slightly depressed lateral margins, expanded anteriorly into inclined lip, with distinct but rounded extensions to coxae, extensions between coxae represented by three pairs of small triangular sclerites separated from sternal margin by unsclerotized cuticle, additional, much larger pair of triangular sclerites situated opposite lateral edges of sternal lip; surface smooth, with few long setae, posterior margin weakly rebordered, separating coxae IV. One weakly sclerotized epimeric sclerite on each side, not extending between coxae, not fused to cara­ pace. Pedicel composed of two dorsal sclerites (anterior sclerite with deep posterior invagination receiving beak­shaped anterior extension of posterior sclerite) and weak, inverted v­shaped ventral sclerite with anteriorly expanded head not reaching posterior tip of sternum.

Abdomen without dorsal or anterior scutum; cuticle with weak, recumbent setae; epigastric scutum weakly sclerotized, with wellmarked booklung openings at sides but without postepigastric sclerites, booklung covers strongly ridged; colulus represented only by scattered setae situated near narrow posterior spiracle. Six spinnerets (figs. 401–406), anterior laterals short, conical, separated by about their diameter at base, with two articles, distal article with one or two major ampullate gland spigots and numerous small, unmodified piriform gland spigots; posterior medians of males triangular, of females bipartite, anterior portion with one or two large minor ampullate gland spigots and few tiny aciniform gland spigots, enlarged posterior portion with two parallel rows, each row with about seven large cylindrical gland spigots; posterior laterals with two articles, those of females with two large cylindrical gland spigots.

Legs laterigrade, formula 2134, most surfaces with long setae; coxae and trochanters without dorsal tubercles, fourth trochanters not elongated; anterior coxae without protuberant posterolateral corners; trochanters very slightly notched, producing sharp point at ventralmost edge; anterior metatarsi and tarsi with undivided scopula composed of short, straight setae; posterior metatarsi with distal preening brushes composed of row of long, thick setae; tarsi with two long, smooth claws bearing no ventral teeth, strong claw tufts composed of two large pads of narrow setae; tarsi without cuticular cracks, extremely short; morphologically dorsal surface with modified proximal margin consisting of patch of unsclerotized cuticle followed by strong cuticular ridge, that ridge opposing distinct distal extensions situated at distal edge of metatarsi; trichobothria present, in three rows on tarsi, two on metatarsi and tibiae. Female palpal femur with strong dorsal spines, distal segments with weaker but longer spines; female palpal tarsus with long claw bearing several tiny ventral teeth, without ventral scopula. Typical leg spination pattern (counts refer to morphological surfaces, only surfaces bearing spines listed): femora I–IV d1­1­1; tibiae: I, II v3­2­2; III, IV v1p­1p­0; metatarsi: I, II v2­1p­0; III v1p­ 0­0.

Male palpal tibia with large basal retrolateral protuberance, retrolateral apophysis enormously elongated, extending to or near tip of cymbium; cymbium with thick distal scopula; cymbial surface distinctly invaginated opposite retrolateral tibial apophysis, along most of its length; tegulum small, embolar base elongated, protruding prolaterally, embolus greatly widened, complex, extending across middle of bipartite median apophysis, prolateral flange of median apophysis bearing retrolaterally directed projection, retrolateral flange reduced to narrow projection, embolus accompanied distally by membranous conductor. External epigynum greatly elongated, with distinct anterior hood situated at level of pedicel, separated from remainder of epigynum by extensible cuticle; pair of c­shaped tubes frequently extend into atrium (may be blind ducts, derived from male palp, or products of secretory glands).

SPECIES GROUPS: Two informal species groups can be recognized. The insidiosus group comprises four species with a bifid retrolateral apophysis tip and strong lateral epigynal margins outlining a v­shaped atrium: L. insidiosa , L. grasspatch , L. zuytdorp , and L. findal . The arcoona group comprises the remaining five species, which have a transversely striated epigynum: L. arcoona , L. whaleback , L. rastellata , L. millewa , and L. yuinmery .

QMB

Queensland Museum, Brisbane

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Trochanteriidae

Genus

Morebilus

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