Metashinobius Wei & Liu, 2025

Cheng, Yufan, Liu, Jie & Wei, Mian, 2025, Metashinobius gen. nov., the second Asian genus with uncleared subfamily placement of Trechaleidae (Araneae, Lycosoidea) from southwest China, with the description of a new species, Biodiversity Data Journal 13, pp. e 153601-e 153601 : e153601-

Metashinobius Wei & Liu gen. nov.

Metashinobius hikariae Wei & Liu . Type species.

Description

Male small-sized (total length approximately 5.00). In dorsal view, carapace pear-shaped, anterior eye row slightly recurved, ALE subequal to AME; posterior eye row recurved, posterior eyes larger than anterior eyes and anterior eye row wider than posterior median eye row. Secondary eyes with grate-shaped tapetum. Cheliceral promargin with 3 teeth, retromargin with 4 teeth, with the third one smaller than the others. Leg formula: 1423. Trochanters notched. Sternum heart-shaped. Colulus present. Colour in alcohol: carapace blackish-green, with a large central pattern and dark margin, four stripes present behind each posterior eyes; cephalic groove and radial furrow black; fovea distinct, longitudinal. Legs yellow-brown, femurs, patellae and the distal tip of tibiae with dark patterns, metatarsi and tarsi brownish-red. Each paired tarsal claw with 12 teeth, unpaired claw with one tooth. For leg spination, see in species description. Abdomen with dark patterns. Male palp same as for the species.

Females unknown.

Diagnosis

The new genus resembles Shinobius Yaginuma, 1991 and can be distinguished from the latter by: 1) having 4 postmarginal teeth (Fig. 2 E), versus having 3 postmarginal teeth in the latter ( Sierwald 1993, Wang et al. 2024, Zhang et al. 2024); 2) the presence of a modified retrolateral tibial apophysis and a large ventrodistal protuberance (Fig. 1 A and B), versus lacking the retrolateral tibial apophysis and having a small ventrodistal protuberance in the latter (figs. 20 and 21 in Sierwald (1993); figs. 3 A and B in Wang et al. (2024); figs. 2 A and B in Zhang et al. (2024)); 3) the median apophysis is thick, with a uplifted ventral division and a lateral division and the tip of the guide groove points downwards (Fig. 1 A, C and D), versus being thin, with a flat ventral division, without lateral division and the guide groove pointed upwards (figs. 20 and 21 in Sierwald (1993); figs. 1 A – D in Wang et al. (2024); figs. 2 A, B, 3 A and C in Zhang et al. (2024)).

Etymology

The generic name is derived from its similarity to Shinobius and the Greek adjective Meta for after. The gender is masculine.

Distribution

Guizhou Province, China

Notes

We place this new genus under the family Trechaleidae by: 1) the posterior eye row being recurved; 2) the presence of a ventrodistal rim of the male palpal tibia; 3) the median apophysis being large and divided into ventral and dorsal divisions, with a dorsal guide groove located on the dorsal division ( Carico 1993). The new genus resembles Shinobius most, but cannot be placed in the subfamily Rhoicininae as the latter, due to the presence of the unique retrolateral tibial apophysis (which is absent in all genera of Rhoicininae); nor can it be accommodated within other trechaleids clade such as subfamily Trechaleinae Simon 1890, based on the Asian distribution and the relatively long anterior eye row. Definitive subfamily classification requires additional specimens to supplement critical morphological data; therefore, the subfamily placement is withheld in the current paper.

Figures

Figure 1. Metashinobius hikariae sp. nov. A, B left palp; C – F right palpal bulb. A, C ventral view; B, F retrolateral view; D dorsal view; E apical view. The red arrow in C indicates the tegular probasal notch, the white dashed line in D indicates the hidden embolus. Abbreviations: C = conductor; DB = dorsal branch of retrolateral tibial apophysis; DD = dorsal division of median apophysis; Em = embolus; G = guide groove; LD = lateral division of median apophysis; MA = median apophysis; RTA = retrolateral tibial apophysis; SD = sperm duct; ST = subtegulum; T = tegulum; TA = terminal apophysis; VB = ventral branch of retrolateral tibial apophysis; VD = ventral division of median apophysis; VP = ventrodistal protuberance.

Figure 2. Male holotype of Metashinobius hikariae sp. nov. A habitus, dorsal view; B the fourth left tarsal claw, retrolateral view; C ocular area, frontal; D carapace, lateral view; E chelicerae, ventral view.