Stahnkeus Soleglad et Fet, 2006

Soleglad, Michael E. & Fet, Victor, 2008, Contributions to scorpion systematics. III. Subfamilies Smeringurinae and Syntropinae (Scorpiones: Vaejovidae), Euscorpius 71 (71), pp. 1-115 : 87-88

Genus Stahnkeus Soleglad et Fet, 2006

Type Species. Vejovis harbisoni Williams, 1970 [= Stahnkeus harbisoni (Williams, 1970) ].

References:

Stahnkeus : Soleglad & Fet, 2006: 29–30, figs. 6–5,

15–16, 30–32, 41–48; Graham & Soleglad, 2007:

1, 3, 12; Soleglad et al., 2007: 134.

Composition. This genus includes five species:

S. allredi (Sissom et Stockwell, 1991) S. deserticola (Williams, 1970)

S. harbisoni (Williams, 1970)

S. polisi (Sissom et Stockwell, 1991) S. subtilimanus (Soleglad, 1972)

Distribution. Mexico (Baja California, Sonora), USA (Arizona, California, Nevada).

This genus (see map in Fig. 202 ) has a disjunct range with two parts, one in southern California, Nevada, and Arizona ( S. subtilimanus , S. deserticola , S. allredi ) and extending into Sonora, Mexico ( S. polisi ), and the other isolated in central Baja California ( S. harbisoni ).

Diagnosis. Modification to basal pectinal teeth of female usually significant, lacking sensorial area variable, affecting 1–4 teeth, blunted and ovoid to swollen and elongated, with little or no distal angling; OD denticles serrated, indistinguishable after OD-3; distal denticle elongated and hook-like with “whitish patch”; inner accessory denticles (IAD) present; subaculear spinoid tooth not present.

Taxonomic history. The genus was separated from Serradigitus by Soleglad & Fet (2006), and the tribe Stahnkeini was established at the same time.

Discussion. Species in Stahnkeus are the largest in tribe Stahnkeini , S. harbisoni and S. subtilimanus reaching lengths of at least 50 mm. These two species and S. deserticola are closely related, showing a distribution extending from the Mojave Desert to central Baja California. The other two taxa, S. polisi and S. allredi , are smaller species, occurring in southern Arizona and coastal Sonora, Mexico.

This unique genus in Stahnkeini is defined by the presence of inner accessory denticles (IAD) found on both the fixed and movable fingers of the chela. This is the only example of IAD in the family Vaejovidae . As reported by Soleglad & Fet (2006: table 6), the number of IAD increases as a specimen progressively reaches maturity. Stahnkeus harbisoni may have as many as 20 ID + IAD denticles on the movable finger.

Figures

Figure 202: General distribution of scorpion subfamily Syntropinae (tribe Stahnkeini) in North America with the ranges of genera Stahnkeus, Serradigitus, Gertschius, and Wernerius delineated.