Mesobuthus Vachon, 1950

Fet, Victor, Kovařík, František, Gantenbein, Benjamin, Kaiser, Ronald C., Stewart, Alexander K. & Graham, Matthew R., 2018, Revision of the Mesobuthus caucasicus complex from Central Asia with descriptions of six new species (Scorpiones Buthidae), Euscorpius 255, pp. 1-77 : 3-7

Genus Mesobuthus Vachon, 1950

( Figs. 1–327, Tables 1–6)

TYPE SPECIES. Androctonus eupeus C. L. Koch, 1839 .

SYNONYMY.

Olivierus Farzanpay, 1987 (syn. by Gantenbein et al., 2003: 417). TYPE SPECIES. Androctonus caucasicus Nordmann, 1840 .

Afghanobuthus Lourenço, 2005 , syn. n. TYPE SPECIES. Afghanobuthus naumanni Lourenço, 2005 (TYPE LOCALITY AND TYPE REPOSITORY. Afghanistan, North range, Vic Shiberghan, Dasht-e-Leili, 400 m; MNHN) = Mesobuthus parthorum ( Pocock, 1889) , syn. n.

DIAGNOSIS. Medium to large buthids, adults 35–90 mm. Sternum type 1 (Soleglad & Fet, 2003), various degrees of an irregular pentagon in shape. Pedipalps orthobothriotaxic, type Aβ ( Vachon, 1974, 1975), femur trichobothrium d 2 dorsal, patella d 3 dorsal of dorsomedian carina. Chelal trichobothrium db usually located between est and esb, or may be on level with trichobothrium est. Trichobothrium eb clearly on fixed finger of pedipalp. Pectines with fulcra. Dentate margin of pedipalp-chela movable finger with distinct denticles divided into 11–14 linear rows and 5 terminal denticles. Chelicerae with typical buthid dentition ( Vachon, 1963, figs. 32–33), fixed finger armed with two denticles on ventral surface. Tergites I–VI granular, with three carinae, tergite VII with 5 carinae. Carapace with distinct carinae, entire dorsal surface nearly planate. First sternite with two granulated lateral stridulatory areas, which however may be reduced in some species. Metasoma elongate, segment I with 10 carinae, segments II- IV with 8–10 carinae. Ventrolateral carinae of metasomal segment V posteriorly usually with several large lobated denticles. Telson elongated or bulbous, bumpy and granulated, without subaculear tooth. Legs III and IV with well developed tibial spurs.

NOTES.

1. The genus Mesobuthus underwent significant taxonomic changes since being listed in the Catalog of the Scorpions of the World by Fet & Lowe (2000). A new species M. cyprius Gantenbein et Kropf, 2000 , was described from Cyprus. Gantenbein et al. (2003) synonymized Olivierus Farzanpay, 1987 , with Mesobuthus . M. nigrocinctus (Ehrenberg, 1828) from Israel and Lebanon was restored from synonymy ( Fet et al., 2000), as well as M. phillipsii ( Pocock, 1889) from Turkey and Iran ( Mirshamsi et al., 2011b). All Indian species were transferred from Mesobuthus to Hottentotta Birula, 1908 by Kovařík (2007); these were Hottentotta pachyurus (Pocock, 1897) , H. rugiscutis (Pocock, 1897; senior synonym of Buthus hendersoni Pocock, 1900 ); and H. tamulus (Fabricius, 1798) . Mesobuthus songi Lourenço, Qi et Zhu, 2005 was also transferred to Hottentotta (Sun et al., 2010; Teruel et Rein, 2010). With the addition of six new species described, and taxonomic changes introduced in this paper, the genus Mesobuthus now includes 24 species.

Our key to Mesobuthus complexes and species (below) excludes taxa from China, Korea, Mongolia, and Singapore, which we have not analyzed. These are: M. bolensis Sun, Zhu et Lourenço, 2010 ; M. extremus (Werner, 1936) ; M. karschius Sun et Sun, 2011 ; M. longichelus Sun et Zhu, 2010 ; and M. martensii (Karsch, 1879) . A comment on M. “ caucasicus ” przewalskii is given in the end of this section. M. agnetis (Werner, 1936) from Iran remains a dubious taxon, possibly a synonym of Sassanidothus zarudnyi (Birula) (Fet & Lowe, 2000) .

2. The monotypic genus Afghanobuthus , with a single species Afghanobuthus naumanni Lourenço, 2005 , is represented by a juvenile from “ Afghanistan, North range, Vic Shiberghan, Dasht-e-Leili”, which the author mistook for an adult female. The juvenile status of this specimen is indicated by size and shape of the genital operculum and pectines (see photos of types located on official MNHN website). Lourenço (2005: 111) cited for genus Afghanobuthus a unique combination of four characters. “(I) Basal denticles of chelicera movable finger absent”. This is not accurate. Some denticles of chelicera are not absent but are not well developed what is typical for most of the studied juveniles of buthids including Mesobuthus . “(II) Absence of inner and outer accessory denticles on pedipalp chela fingers”. However, his own figure 2 (Lourenço, 2005: 112) shows some accessory denticles (granules). This character, as we have observed, has been misinterpreted by Lourenço. For example Lourenço (2006: 63) wrote: “Due the variability observed in the structure of fixed and movable finger dentition, Buthacus mahraouii shows very small external accessory granules which, possibly are not illustrated precisely in my figure”, and disputed validity of the character through “variability”. However, our study suggests that this character is applic- able well for the adults but the accessory granules could be smaller or missing in juveniles. “(III) Sternum pentagonal”. This is not accurate. We can define it better as “sternum type 1 (Soleglad & Fet, 2003), various degrees of an irregular pentagon in shape” according to the photos located on the official MNHN website and fig. 5 in Lourenço (2005: 112). Again we find no difference between Afghanobuthus and Mesobuthus . “(IV) Small size”. In reality the small size 27.3 mm of Afghanobuthus naumanni holotype justifies the fact that it is a juvenile of the species whose adults could be 55–85 mm long as Mesobuthus parthorum inhabiting the same area in Afghanistan.

Apart from the above points, the holotype of Afghanobuthus naumanni and a juvenile of Mesobuthus parthorum ( Fig. 321) match each other precisely in the following key characters: trichobothrial pattern, structure of sternum and genital operculum, pectinal tooth count and lamellar structure, proportions, setation, carination and sculpture of pedipalps, carapace, tergites, sternites, and metasoma, shape and armature of the telson, as well as armature of chelicerae and pedipalp fingers.

The inevitable conclusion is that Afghanobuthus naumanni Lourenço, 2005 is a junior synonym of Mesobuthus parthorum ( Pocock, 1889) .