Ischnothyreus Simon 1893
Creators: name: Richard, Miguel
name: Graber, Werner
name: Kropf, Christian
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Oonopidae
Ischnothyreus

description: Genus Ischnothyreus Simon, 1893
Type species Ischnothyreus peltifer (Simon) 1891
Diagnosis. Ischnothyreus synapomorphies: Males possess heavily sclerotized “burnt” palps (e. g. Figs. 1 D–G) which are associated with an elaborate internal skeletomuscular system in the anterior part of the elevated carapace (Dumitrescu and Georgescu 1983). These endoskeletal elements are visible through the carapace cuticle and appear as egg-shaped patches that are somewhat darker than the rest of the carapace (e. g. Figs. 31 E, 32C). The resting position of the male palps is characteristic, as they are held twisted retrolaterally, lying flat at the sides of the endites and sternum (e. g Figs. 1 D–G). Male palps of Ischnothyreus show a fusion of cymbium and bulb but with a visible seam (se, Fig. IC). Males of most species of Ischnothyreus possess conspicuous processes on the base of the cheliceral fang (p, e. g. Figs. 19 C, D). Females of Ischnothyreus show an elongated, asymmetrically curved and highly sclerotized convoluted duct (winding tube) in their genital area underneath the centre of the postepigastric scutum (wt, e. g. Fig. 15 E) (Burger 2010). The winding tube is laterally flanked by two apodemes (a, e. g. Fig. 15 E) in most species of Ischnothyreus. Females also show very diverse and species-specific modifications of the postepigastric scutum (e. g. nsp Fig. 16 G). The postepigastric scutum bears a row or field of pores (po, e. g. Fig. 16 F) connected to the winding tube (Burger 2010).
General morphology of the male pedipalp:
Male pedipalps of Ischnothyreus show several conspicious features: Besides the fusion of cymbium and bulb there is also a partial fusion of trochanter, femur and patella (pfj, Figs. IC, D). The trochanter is strongly modified, with ventral projections (tvp, Figs. IC, D). The bulb shows one or two protuberances on the ventral side (vp, Fig. ID) and a retrolateral lobe distally close to the embolic region (rl, Fig. ID) (e. g. Kranz-Baltensperger 2011, Saaristo 2001). The embolic opening is often on the prolateral side (eo, Fig. IC) and there are often lesssclerotized processes in the embolic region (ssa, Figs. IC, D). Three trichobothria are situated on the dorsal side of the tibia (t, Figs IA, B). Three strings of unknown function (str, Figs. IE, F) pass through the segments of male pedipalps from the endite to the bulb.
Description of the genus Ischnothyreus: see e. g. Edward and Harvey 2014.
FIGURE I. Ischnothyreus male left pedipalp: 1, 3, prolateral view; 2, 4, retrolateral view; 5, bulb, lateral view; 6, femurtrochanter. eo, embolic opening; pfj, partially fused joints; rl, retrolateral lobe; se, seam; ssa, slightly sclerotized appendage; str, strings; t, trichobothria; tvp, trochanter ventral projection; vp, ventral protuberance.
description: Published as part of Richard, Miguel, Graber, Werner & Kropf, Christian, 2016, The goblin spider genus Ischnothyreus (Araneae, Oonopidae) in Java and Sumatra, pp. 1-99 in Zootaxa 4151 (1) on pages 5-6, DOI: 10.11646/zootaxa.4151.1.1, http://zenodo.org/record/262273