Pseudouroctonus peccatum, a new scorpion from the Spring Mountains near “Sin City, ” Nevada (Scorpiones, Vaejovidae)Administrator on December 28, 2013 in Online Arachnid Publications, Recent News, Scorpions in North America No Comments »
A new scorpion species is described from the Spring Mountain Range near Las Vegas, Nevada. The new species appears to be geographically isolated from other closely related species ofUroctonites Williams & Savaryand Pseudouroctonus Stahnke. We tentatively place the new species in Pseudouroctonus and provide detailed descriptions and illustrations of type material. We compare the new species to 17 congeneric taxa, briefly discuss the taxonomic history ofPseudouroctonus, and provide DNA barcodes for two paratypes to assist ongoing research on the systematics of family Vaejovidae.
Low dispersal potential and ecological specialization (stenotopy) are thought to make certain groups of scorpions predisposed to accelerated diversification (Prendini 2005; Bryson et al. 2013a). Scorpions restricted to highland ecosystems are particularly diverse, perhaps resulting from allopatric divergence on small spatial scales (microallopatry, see Fitzpatrick et al. 2008) facilitated by historical changes in geomorphology and climate regimes (Bryson et al. 2013a,2013b). Recently, this hypothesis has been repeatedly supported by the discovery of numerous new scorpion species from isolated mountain ecosystems, especially from the “sky islands” region of the North American aridlands (Graham 2007; Ayrey 2009, 2012; Graham and Bryson 2010; Ayrey and Soleglad 2011; Hughes 2011; Graham et al. 2012; Sissom et al. 2012; Ayrey and Webber 2013).
The Spring Mountain Range, located just outside of Las Vegas in southern Nevada, is among the most insular of the sky islands, reaching elevations more than 3, 400 m above the Mojave Desert lowlands. While conducting diurnal surveys for myriapods in the Spring Mountains, we serendipitously discovered yet another new scorpion that appears to be restricted to a sky island ecosystem. After numerous diurnal and nocturnal (using UV light; Stahnke 1972) surveys, we only managed to collect a total of five individuals from mixed pine-oak woodlands in Kyle Canyon, one of the most heavily visited regions in the Spring Mountains. Unfortunately, forest fires ravaged the type locality shortly after we collected the type series and surveys in other areas of the mountains were unsuccessful.
The new species is clearly a member of family Vaejovidae, and is most similar to generaPseudouroctonus and Uroctonites, both of which are stenotypic and contain species endemic to sky island ecosystems in southwestern North America. Interestingly, the Spring Mountains are situated in the middle of a substantial gap between the known distributions of these two genera (Fig. 1), so the new species could prove to be a missing link in our understanding of the biogeography of this group (Bryson et al. 2013a) and the southwestern sky islands. Herein, we tentatively place the new species in Pseudouroctonus, although we predict that the genus is polyphyletic and in need of a thorough systematic revision.
Since the population at the type locality may have been extirpated during recent fires, we provide DNA barcodes (COI) for two specimens (paratypes) to assist colleagues in their ongoing research on the biogeography and systematics of family Vaejovidae. Given that the species went undetected for so long despite occurring in a populated region near one of the most visited cities in the world, we suspect that similar new species may still await discovery in the more remote and less-explored sky islands of southern Nevada and California.
Brief taxonomic history. Of the 22 species and subspecies currently comprising generaPseudouroctonus and Uroctonites (including the new species described herein), sixteen were described by Gertsch and Soleglad (1972). At that time, twelve of these species were placed in genus Uroctonus (now in family Chactidae) and the other four in genus Vaejovis. Stahnke (1974)moved most of the species placed in Uroctonus into genus Vaejovis and created the new genusPseudouroctonus solely for Pseudouroctonus reddelli. Stockwell (1992) reversed most of Stahnke’s taxonomic acts by moving the species Stahnke placed in Vaejovis intoPseudouroctonus. In their important paper, Williams and Savary (1991) defined the new genusUroctonites comprised of a new species, Uroctonites giulianii, and three Pseudouroctonus species originally defined by Gertsch and Soleglad (1972). Finally, four other species have now been placed in Pseudouroctonus: Pseudouroctonus minimus minimus (Kraepelin, 1911),Pseudouroctonus glimmei Hjelle, 1972, Pseudouroctonus sprousei Francke & Savary, 2006, andPseudouroctonus saavasi Francke (2009). See Soleglad and Fet (2003: 103–104) for a more detailed discussion on the taxonomic history of these interesting scorpions.