Ischnothyreus bauri Richard

Richard, Miguel, Graber, Werner & Kropf, Christian, 2016, The goblin spider genus Ischnothyreus (Araneae, Oonopidae) in Java and Sumatra, Zootaxa 4151 (1), pp. 1-99 : 11-15

Ischnothyreus bauri Richard , sp. nov.

( Figs. 4–6 )

Type material. Holotype: male (PBI_OON00052400), JAVA: E . Java, Mt. Ljen , 600m, July 8, 1979, coll. Deeleman, NNM Leiden.

Etymology. The species epithet is dedicated to Hannes Baur, a NMBE entomologist and specialist of Hymenoptera and Orthoptera.

Diagnosis. Males of I. bauri sp. nov. can easily be distinguished from all other Ischnothyreus species by the huge protruded clypeus, which separates the ALE from the anterior edge of the chelicerae by approximately twice their diameter in lateral view ( Figs. 4 D–G), by the modified chelicerae which are strongly sclerotized on the prolateral side of the paturon and the fang which is thickened from the base almost to the tip (tf, Figs. 6 A–C).The paturon of the fang bears a conspicuous notch proximally on the prolateral side and has two characteristic denticles (n, d, Figs. 6 A–C). The palpal bulb is characteristically shaped with its big retrolateral lobe and the short and blunt tip with the less sclerotized appendage (rl, lsa, Figs. 5 E, F). The bulb has two ventral protuberances which are small and pointed ( Figs. 5 A, B, E, F).

Description. Male: (PBI_OON00052400). Total length 1.70; carapace length: 0.83; carapace width: 0.64; abdomen length; 0.80.

CEPHALOTHORAX: Carapace yellow, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view, anteriorly narrowed to between 0.5 and 0.75 times its maximum width, surface of elevated portion of pars cephalica smooth, sides smooth; lateral margin straight, smooth. Clypeus very large, protruding, more than twice the diameter of ALE in frontal view. margin unmodified, curved downwards in front view, sloping forward in lateral view, high, ALE separated from edge of carapace by more than their diameter. Eyes six, well developed, ALE largest, all eyes oval; posterior eye row procurved from both above and front; ALE touching, ALE-PLE touching, PME touching for less than half their length, PLE-PME touching. Sternum as long as wide, yellow, uniform, with radial furrows between coxae I–II, II–III, III–IV, furrow smooth, surface smooth, microsculpture absent, lateral margin without infra-coxal grooves, distance between coxae approximately equal, extensions of precoxal triangles present, lateral margins unmodified; setae dark, needle-like, evenly scattered, originating from surface. Mouthparts: Chelicerae, endites and labium yellow. Chelicerae straight, cheliceral fang strongly thickened on proximal 2/3, resembling a flamingo beak in shape; directed medially, tip unmodified; setae dark, needle-like, evenly scattered, paturon and paturon base prolaterally strongly sclerotized with notch and two characteristic denticles. Fang strongly thickened (n, d, tf, Figs. 6 A–C).

Labium elongated hexagon, not fused to sternum, anterior margin not indented at middle, same as sternum in sclerotization; with setae. Endites distally not excavated, anteromedian tip with one strong, tooth-like projection, much more heavily sclerotized than sternum.

ABDOMEN: ovoid, pointed posteriorly; dorsum soft portions white, without color pattern. Posterior spiracles not connected by groove, scutum not extending far dorsal of pedicel. Dorsal scutum weakly sclerotized, yellow, without color pattern, covering less than 1/2 of abdomen, between 1/4 and 1/2 abdomen width, not fused to epigastric scutum, middle surface smooth, sides smooth. Epigastric scutum weakly sclerotized, surrounding pedicel, not protruding, small lateral sclerites absent. Postepigastric scutum weakly sclerotized, yellow, short, only around epigastric furrow, not fused to epigastric scutum, anterior margin unmodified. Dorsum setae present, dark, needle-like. Spinneret scutum with fringe of needle-like setae.

LEGS: yellow, without color pattern; patella plus tibia I shorter than carapace, tibia I unmodified. Leg spination: femora: I p0-1-1; II p0-0-1; tibiae: I, II p2-2-0; r2-2-0; metatarsi: I, II p1-1-0; r1-1-0. GENITALIA: Epigastric region with sperm pore large, oval, situated at level of anterior spiracles, unmodified. Bulb with double ventral protuberances, retrolateral lobe large. Tip of bulb short, blunt, with distal less-sclerotized appendage (rl, lsa, Figs. 5 A, B, E, F).

Female: Unknown.

Distribution. Only known from Mt. Ljen in eastern Java.

Figures

FIGURE 4. Ischnothyreus bauri sp. nov. Male: A, habitus, dorsal view; B, habitus, lateral view; C, habitus, ventral view; D, carapace, dorsal view; E, carapace, lateral view; F, carapace, frontal view; G, sternum, ventral view. Scale bar: A = 1 mm.

FIGURE 5. Ischnothyreus bauri sp. nov. Male: A, E, left bulbus and cymbium, prolateral view; B, F, left bulbus and cymbium, retrolatral view; C, left embolus, prolateral view; D, left embolus, retrolateral view. lsa, less sclerotized appendage; rl, retrolateral lobe. Scale bars: A, E = 0.1 mm.

FIGURE 6. Ischnothyreus bauri sp. nov. Male: A, chelicerae, posterior view; B, right chelicera, posterior view; C, right chelicera, anterior view. d, denticles; n, notch; tf, thickened fang. Scale bars: A = 0.2 mm; B = 0.1 mm.