Shaanxinus anguilliformis Tanasevitch, 2006: 296

Lin, Shou-Wang, Lopardo, Lara, Haase, Martin & Uhl, Gabriele, 2019, Taxonomic revision of the dwarf spider genus Shaanxinus Tanasevitch, 2006 (Araneae, Linyphiidae, Erigoninae), with new species from Taiwan and Vietnam, Organisms Diversity & Evolution (New York, N. Y.) 19 (2), pp. 211-276 : 222-225

Shaanxinus anguilliformis Tanasevitch, 2006: 296 (transfer from Walckenaeria ).

Type material.> Holotype: ♂, 15.VI.1986 Zhangshiguan (38.0° N, 114.5° E), Shijiazhuang, Hebei Province, collected by Zhu, Mingsheng, not examined . Paratypes: 3♂ 6♀, same locality and date as holotype, not examined. Deposited in the Department of Cellular Biology , Norman Bethune University of Medical Science, Changchun, China .

Remarks. According to Shuqiang Li (Beijing, personal communication, 2017), all specimens of this species have been lost, along with all other spider specimens previously stored in the Department of Cellular Biology, Norman Bethune University of Medical Sciences, Changchun, China (now Norman Bethune Health Science Center of Jilin University). Consequently, the only available morphological reference for this species is the original description by Xia et al. (2001). For the purpose of interspecific comparison and diagnosis, the morphological content of the aforementioned article is rather incomplete and therefore this species was not included in our phylogenetic analysis. For example, there is no statement about male cheliceral mastidia, nor whether the clypeus is hirsute. One of the drawings, however, suggests a rather glabrous clypeus and clypeal groove (figs. 3–4 in Xia et al. 2001: 168). Unless the lack of setae is due to omission, this would be a substantial difference from all other cogenerics. Moreover, tibial chaetotaxy was also not stated. On the other hand, the drawings of the male palp (although with low resolution) suggest a similar cogeneric configuration of the ED. The embolus seems to be thicker than in all other species. The epigyne drawings in figs. 6–7 in Xia et al. (2001): 168 indicate copulatory openings situated anterior to spermathecae, and the dorsal plate seems to have a middle ridge or scape, which are significantly different from all other Shaanxinus species with known females. Several features indicate a close relationship between S. rufus and S. anguilliformis in comparison to other species. In both species, the legs II are much longer than the first pair. The species also share a similar shape of the PC tip. In addition, if the interpretation of the spermophore is correct (a dark band in retrolateral view of tegulum in fig. 2, Xia et al. 2001: 168), then the curvature is similar to that in S. rufus . The ARS is also not depicted, and it is here interpreted as absent. Absence of ARS also occurs in S. rufus . Despite difficulties impeding interspecific comparison, according to the shared features of S. anguilliformis with congenerics and lack of evidence indicating closer relationship with other taxa, this species remains in the current classification.

Description. See Xia et al. (2001)

Distribution. Hebei Province, China

Shaanxinus magniclypeus Lin sp. n.

Figs. 2a , 8 , 9 , 10 , 11 and 12

Material: see below, as listed for the two geographical populations.

Derivatio nominis. The specific name is derived from the Latin B magnus,^ meaning tall, and clypeus, referring to the especially tall clypeal region. The name is a noun in apposition.

Diagnosis. Males: Clypeus completely hirsute, central lower region not glabrous ( Figs. 9d and 11d ), a feature only shared with S. hirticephalus sp. n.; clypeal groove upper and lower margins not in contact, setae in groove short and thin, vertically oriented, which distinguishes this species from S. mingchihensis sp. n., S. makauyensis sp. n., S. curviductus sp. n., S. tsou sp. n., S. meifengensis sp. n., S. hehuanensis sp. n., S. lixiangae sp. n., S. seediq sp. n., and S. atayal sp. n.; PC tip simple, spoon-shaped; distal seta absent, mesal apophysis present, retrolateral apophysis absent ( Figs. 8a, c and 10a, c ), a combination of features only shared with S. tamdaoensis sp. n. Spermophore in retrolateral tegulum relatively weakly curved ( Figs. 8d and 10d ) (see generic description). Embolus short ( Figs. 8e and 10e ) (see generic description).

Females: general appearance of epigyne similar to S. shihchoensis sp. n. and S. shoukaensis sp. n., with dorsal and ventral plates not extended posteriorly; copulatory duct length shorter than these two species; shape of copulatory opening different from S. shihchoensis sp. n. by having less laterally extended dorsal plate; different from S. shoukaensis sp. n. because the latter has ventral plate extended ventrally over the dorsal plate at copulatory opening ( Figs. 8g, h and 10g, h ; see description and figures of S. shihchoensis sp. n. and S. shoukaensis sp. n.).

Remarks. Individuals collected from Hualien County and Pingtung County (Eastern population) showed morphological differences from those collected from Taipei City and New Taipei City (Northern population), and are described here separately.

Figures

Fig. 2 Palpal tibia of a Shaanxinus magniclypeus sp. n. and b S.hehuanensis sp. n., dorsal view

Fig. 8 Shaanxinus magniclypeus sp. n., Eastern population, a–e Male left palp, drawings and photos. a, d Retrolateral view. b Prolateral view. c Ventral view. e Apical view. f–h Epigyne, photo and drawings. f, h Ventral view, Bd^ dorsal plate, Bv^: ventral plate. g Dorsal view. Scale bars 0.10 mm

Fig. 9 Shaanxinus magniclypeus sp. n., Eastern population, photos. a–d Male habitus. e–h Female habitus. a, e Dorsal view. b, f Lateral view. c, g Ventral view. d, h Frontal view. Scale bars 1 mm

Fig. 10 Shaanxinus magniclypeus sp. n., Northern population, a–e Male left palp, drawings and photos. a, d Retrolateral view. b Prolateral view. c Ventral view. e Apical view. f–h Epigyne, photo and drawings. f, h Ventral view, Bd^ dorsal plate, Bv^ ventral plate. g Dorsal view. Scale bars 0.10 mm

Fig. 11 Shaanxinus magniclypeus sp. n., Northern population, photos. a–d Male habitus. e–h Female habitus. a, e Dorsal view. b, f Lateral view. c, g Ventral view. d, h Frontal view. Scale bars 1 mm

Fig. 12 Collecting sites of Shaanxinus in Taiwan. Two or more symbols next to each other represent sites where multiple species were collected; the location is at the center between symbols