Diplocephalus mirabilis Eskov 1988
Creators: name: Song, Yanjing
name: Li, Shuqiang
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Diplocephalus
Diplocephalus mirabilis

description: Diplocephalus mirabilis Eskov, 1988 (Figs 6-8)
Diplocephalus mirabilis Eskov, 1988: 18, figs 18-24 (type locality: Magadan Area, Russia).
MATERIAL EXAMINED. — Russia. Russia Far East, Aborigen field station, Sibit-Tyellakh River Basin, Upper Kolyma River, summer 1986, coll. Yura M. Marusik, det. Yura M. Marusik, 2 ♀♀, 2 ♂♂ (IBPN).
China. Jilin Province, Mt Changbaishan, 42.03°N, 127.98°E, 11.VIII.1985, 6 ♀♀, 3 ♂♂ (JLU).
DISTRIBUTION. — Russia, China (Jilin) (Song et al. 1999; Platnick 2008) (Fig. 12).
DESCRIPTION
Male
Total length 1.53. Carapace 0.76 long, 0.61 wide, dull yellow, slightly swollen, bearing shallow postocular sulci; with hairs densely distributed in the ocular area and on the clypeus (Fig. 7A). Abdomen grey yellow. Clypeus 0.16 high. AME diameter 0.03, ALE 0.04, PME 0.03, PLE 0.04, AME interdistance 0.75 times their diameter, AME-ALE interdistance 1.00 times ALE diameter, PME interdistance 2.20 times their diameter, PME-PLE interdistance 1.33 times PLE diameter.Sternum 0.40 long, 0.42 wide. Coxa IV interdistance 1.20 times their width. Chelicerae with 6 promarginal teeth, 5 retromarginal teeth (Fig. 6D).Tibia I 5.46 times longer than deep. Tm I 0.43, Tm IV absent. Dorsal spines on tibia of leg IV: 2-2-1-1; dorsal spine on patella of leg IV: 1-1-1-1. Leg measurements: I: 1.89 (0.55, 0.21, 0.44, 0.35, 0.34); II: 1.74 (0.51, 0.19, 0.39, 0.34, 0.30); III: 1.54 (0.43, 0.20, 0.33, 0.32, 0.28); IV: 2.03 (0.58, 0.21, 0.52, 0.42, 0.30).
Palp:tibia produced into a strongly curved, acerate prolateral apophysis whose base extended retrolaterally to form a triangular membrane; with 1 retrolateral and 1 prolateral trichobothrium (Fig. 6E). Paracymbium spiral, with terminal part hooked (Fig. 6B). Tegulum distal to subtegulum in unexpanded palp. Suprategulum produced into a dentiform marginal apophysis and a bifurcate distal apophysis modified with mini membrane distally (Fig. 7D). Somewhat rounded embolic membrane totally covered by embolic division (Fig. 7C). Anterior radical process crescent-shaped in retrolateral view (Fig. 6B), almost parallel with moderately long embolus (Fig. 6C). Tailpiece nearly straight and broad distally (Fig. 7B, C). Lamella characteristica is cupped distally to accommodate the distal end of the embolus (Fig. 6C).
Female
Total length 1.50. Carapace 0.69 long, 0.50 wide, similar to male in general appearance and coloration, but without cephalic sulci. Abdomen light grey. Clypeus 0.12 high. AME diameter 0.03, ALE 0.05, PME 0.09, PLE 0.09, AME interdistance 0.44 times their diameter, AME-ALE interdistance 0.63 times ALE diameter, PME interdistance 1.00 times their diameter, PME-PLE interdistance 0.50 times PLE diameter. Sternum 0.43 long, 0.40 wide. Coxa IV interdistance 1.00 times their width. Chelicerae with 6 promarginal teeth, 5 retromarginal teeth. Tibia I 4.57 times longer than deep. Tm I 0.47, Tm IV absent. Dorsal spines on tibia of leg IV: 2-2-1-1; dorsal spine on patella of leg IV: 1-1-1-1. Leg measurements: I: 1.80 (0.53, 0.20, 0.40, 0.36, 0.31); II: 1.64 (0.48, 0.18, 0.34, 0.33, 0.30); III: 1.46 (0.41, 0.19, 0.29, 0.31, 0.26); IV: 1.92 (0.58, 0.18, 0.48, 0.41, 0.28).
Epigynum seems to be unique among the congeners by the presence of unciform apophyses holding more or less perpendicular to the surface of the axis of the body (Fig. 7E, H). Dorsal plate small, totally covered by the ventral plate in ventral view (Fig. 7 F-H). Copulatory openings may be at the anterior end of the fissure (Fig. 7H). Copulatory ducts enclosed in a sclerotized capsule (Fig. 8A, B). Two extra linguiform extensions exposed after the tegument of epigynum was removed (Fig. 8A, B). A deep groove presented at the outer margin of each extension (Fig. 8A). Ducts were also observed along the outer margins of the grooves, but it is difficult to confirm what they really are at present (Fig. 8A). Maybe they are parts of the copulatory ducts. Fertilization ducts thin, moderately long, mesally oriented (Fig. 8A). Spermathecae reniform and separated by a distance of their length (Fig. 8B). The path of copulatory ducts is shown in Figure 8A.
REMARKS
Based on the shape of moderately long embolus and male palpal tibial apophysis, D. mirabilis displays certain affinities with Eurasian species, Diplocephalus bifurcatus Tanasevitch, 1989 (Turkmenistan), Diplocephalus connatus Bertkau, 1889 (Palearctic), Diplocephalus dentatus Tullgren, 1955 (Northern, Central Europe to Ukraine), Diplocephalus graecus (O. P.-Cambridge, 1872) (Southern, Central Europe, North Africa), Diplocephalus helleri (L. Koch, 1869) (Europe), Diplocephalus hungaricus Kulczyn’ski, 1915 (Hungary), Diplocephalus latifrons (O. P.-Cambridge, 1863) (Europe, Russia), Diplocephalus protuberans (O. P.-Cambridge, 1875) (Europe), Diplocephalus sphagnicola Eskov, 1988 (Russia, Canada) and Diplocephalus subrostratus (O. P.-Cambridge, 1873) (Holarctic) and African species, Diplocephalus algericus Bosmans, 1996 (Algeria), but differs by the presence of large cradle-shaped lamella characteristica of male palp. Furthermore, females of D. mirabilis can be separated from all the worldwide known congeners by the presence of unciform apophyses of epigynum.
5 ♂♂ and 8 ♀♀ were measured.Total length varies from 1.47-1.67 in males, 1.45-1.56 in females. Carapace length is 0.70-0.78 in males, 0.67-0.69 in females; width 0.59-0.61 in males, 0.48-0.50 in females. The shape of post-ocular sulci is variable. Specimens collected form Russia show deep postocular sulci, but specimens from China appear less deep or only strongly pigmented.
description: Published as part of Song, Yanjing & Li, Shuqiang, 2010, The spider genera Araeoncus Simon, 1884 and Diplocephalus Bertkau, 1883 (Arachnida, Araneae, Linyphiidae) of China, pp. 117-137 in Zoosystema 32 (1) on pages 128-132, DOI: 10.5252/z2010n1a6, http://zenodo.org/record/4520640