urn:lsid:zoobank.org:act: 701C6466-5B03-46D5-ADD2-42A4EFDACA21

Figs 1, 4–10, 17–21

Type material. Holotype female (MHBU), China: Xinjiang, northern piedmont of the Tianshan Mountains, 10km S of Jinghe County, 44°31'N, 82°54'E, 7 Aug. 2008, M. S. Zhu, F. Zhang, G. X. Han and D. Sun leg.; 1 juvenile female (MHBU) and 1 juvenile male (MHBU) paratypes, all the same as for holotype.

Diagnosis. Species of moderate size, with respect to the genus. General coloration yellow to pale brownish-yellow; ventral and lateral surfaces of metasoma segment V with inconspicuous variegated black pigment. Chela smooth without carinae, long and slender. The metasoma segments elongate; median lateral carinae complete on segment I, only with sparse granules and covered 1/2–2/3 length of segment on II and obsolete, remaining 1–2 granules at distal end on III; ventrolateral carinae of segment V strong, serrate, becoming strongly marked posteriorly and with 2–3 markedly large and extroversive lobed granules; aculeus markedly longer than a half of telson length.

Figure Ι. Mesobuthus longichelus sp. n. Female holotype. Dorsal view. Scale bar = 5.0 mm.

Dentate margins of movable and fixed fingers with 12 and 11 oblique rows of granules. Pectinal tooth count 22–23 in females and 27–28 in male. Mesobuthus longichelus sp. n. is undoubtedly associated with Mesobuthus caucasicus intermedius and Mesobuthus caucasicus przewalskii, but it can be distinguished by above features, and especially by these three characters: the shape of chela, the median lateral carinae of segment II and III on metasoma, and the shape of ventrolateral carinae of segment V on metasoma.

Figures 2–Ι0. 2 Mesobuthus caucasicus intermedius (Birula, 1897). Female 3 Mesobuthus caucasicus przewalskii (Birula, 1897). Female 4–Ι0 Mesobuthus longichelus sp. n. Female holotype. 2–4 Carapace, dorsal aspect 5 Genital operculum and pectines, ventral aspect 6–7 Patella (6. dorsal, 7. external) 8 Femur, dorsal aspect 9–Ι0 Chelicera (9. ventral, 10 dorsal). Scale bar = 1.0mm.

Etymology. The specific name derives from the Latin “ longi + chel ”, meaning long and chela, referring to the long and slender chela, especially the manus.

Description. Based on female holotype.

Coloration. Basically brownish-yellow. Prosoma: carapace brownish-yellow, with only blackish anterior median carinae, other carinae without pigment; eyes surrounded by black pigment. Mesosoma: brownish-yellow; segments I to VI with a distinct black-