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Checklist to the American Scorpion Genera Paruroctonus and Smeringurus

The scorpion genera Paruroctonus and Smeringurus in the United States

Family Vaejovidae Thorell, 1876. (14 genera)
Genus Paruroctonus Werner, 1934
Three groups, nine subgroups, 32 species, 10 subspecies.
Genus Smeringurus Haradon, 1983
Three species, two subspecies.
Distribution: Western North America and Mexico.

The genus Paruroctonus is the largest in North America north of Mexico. Unfortunately, most species are indistinguishable from one another except when examined under magnification. Generally, all members of the genus have a series of long hairs on the dorsal surfaces of the feet (bristlecombs) which are more highly developed in psammophilous (sand-dwelling) species and all species lack dorsal spines on the segments of the metasoma (tail). In most cases, the hands of the pedipalps are robust. The vast majority of Paruroctonus species lack pigment and appear pale yellow.
They also all (both genera) lack spines on the metasoma segments.
The genus Smeringurus was a subgenus of Paruroctonus described by Richard Haradon in 1983. It was later raised to a genus by Scott Stockwell in 1992. The species are large (in excess of 80 mm) and only one species is a sand dweller (see below).

Additional unpublished distributions are provided courtesy of Joe L. Bigelow, who is preparing The Scorpions of Arizona for publication. Other surveys in preparation include the scorpions of New Mexico, by David Sissom, and the scorpions of the Texas Panhandle, by Sissom, McWest, Hendrixson, and Capes. Other references include the published descriptions of each species, the revisionary series of papers by Richard Haradon, and Field Guide to the Spiders and Scorpions of Texas by John A. Jackman. Also check out the recently released Catalog to the Scorpions of the World, by Victor Fet, W. David Sissom, Graeme Lowe, and Matt Braunwalder (this volume was not used as a reference for the lists that follow).

Thanks to Joe L. Bigelow, Chad M. Lee, and Brent Hendrixson for providing useful information to help this site look better.

Kari J. McWest

This site is still under construction

boreus group
baergi subgroup

Paruroctonus arenicola arenicola Haradon, 1984
Distribution: Nevada: Nye County in sand dunes of Amargosa Desert.

Paruroctonus arenicola nudipes Haradon, 1984
Distribution: California: San Bernardino County in sand dunes of Mojave Desert.

Paruroctonus baergi (Williams and Hadley, 1967)
Distribution: Sandy areas in the Colorado Desert. Arizona: La Paz and Yuma counties. California: Imperial, Riverside, and San Bernardino counties. Mexico: Northwestern Sonora.

Paruroctonus boquillas Sissom & Henson, 1998
Link Photo of paratype female P. boquillas courtesy of and Copyright 1999 W. D. Sissom (Many Thanks!).
Distribution: Known only from the sand dunes along the Rio Grande in Boquillas (bo-KEY-uss) Canyon, Big Bend National Park, Brewster County, Texas.

Paruroctonus marksi Haradon, 1984
Distribution: California: Los Angeles County, in sand dunes of the western Mojave Desert.

* Paruroctonus utahensis (Williams, 1968)
Distribution: Widespread and locally abundant. Sandy regions of the Colorado Plateau, New Mexico, Texas, and the northern Chihuahuan Desert. Utah: Garfield, Emery, Grand, and San Juan counties; *Arizona: Sand dunes of northern Apache, Cochise, Coconino, Navajo and southeastern *Graham and Greenlee counties (specific localities to be published in Scorpions of Arizona by Joe L. Bigelow); * New Mexico: Widespread in sandy regions throughout the state, including *White Sands (*other specific localities not yet published). *Texas: El Paso, Ward, and Winkler counties. Also in the * Panhandle (Jackman, 1997; specific localities not yet published).
Mexico: Chihuahua, west of El Paso.

becki subgroup

* Paruroctonus becki (Gertsch and Allred, 1965)
Distribution: *Arizona: Arizona Strip of Mohave and *Coconino counties, north and west of the Colorado River (specific localities not yet published; courtesy Bigelow); California: Riverside, Los Angeles, San Bernardino, Kern, and Inyo counties. Nevada: Clark, Nye, and Churchill counties. Utah: Washington County.

boreus subgroup

Paruroctonus bantai bantai (Gertsch and Soleglad, 1966)
Distribution: California: Inyo County, Saline Valley.

Paruroctonus bantai saratoga Haradon, 1985
Photo Courtesy of and Copyright 2000 Graeme Lowe.
Distribution: California: San Bernardino County, Salt flats at Saratoga Springs, Death Valley.

Paruroctonus boreus (Girard, 1854)
northern scorpion
Photo of concolorous (auratus) form courtesy of and Copyright 1999 R. David Gaban.
Photo of common P. boreus (preserved female from Idaho) by KJM and W.M. Burrell Copyright 2001.
Photo of live female from Alberta, Canada, courtesy of and Copyright 2001 Prof. Dan Johnson, University of Lethbridge.
Distribution: Common in a variety of habitats and elevations (to over 2000 m, 7000 ft). Western North America, from southern Canada to northern Arizona to eastern California, essentially excluding the northwest coastal region and the Mojave and Sonora Deserts. The northern scorpion probably occurs in northwestern New Mexico (Gertsch and Soleglad 1966).
Canada: British Columbia: Okanagon Lake Valley; Alberta: Medicine Hat to Red Deer and Calgary. Sasketchewan?
USA: Washington, Oregon, California, Idaho, Montana, North Dakota, Nevada, Colorado, Utah, Wyoming, and northern Arizona.

Paruroctonus maritimus Williams, 1987
Monterey Dunes scorpion
Distribution: California: Monterey County, Seaside, and dunes surrounding Monterey Bay.
Note: This species has been proposed as an Endangered Species due to habitat destruction.

Paruroctonus silvestrii (Borelli, 1909)
Photo of adult P. silvestrii courtesy of a copyright 1999 Graeme Lowe; compared with adult female Uroctonus mordax from near Mt. Diablo, CA, courtesy of and copyright 2001 Martin Cross. These two species are common and occasionally occur together in western California.
Distribution: California, USA and Baja California Norte, Mexico, from Progreso, Baja California Norte, to Marin County and Lake Tahoe, California.
Fairly common in almost every habitat in its range, from coastal dunes to high-elevation conifer forests.
Photo of Paruroctonus silvestrii from San Diego County, California.

xanthus subgroup

Paruroctonus xanthus (Gertsch and Soleglad, 1966)
Photo of P. xanthus courtesy of and Copyright 2000 Graeme Lowe.
Distribution: California: Winterhaven, Imperial County; Arizona: Active, transient dune fields of the Great Altar Desert of southern Yuma County, Arizona and northwestern Sonora, Mexico (specific localities not yet published; courtesy Bigelow).
Mexico: San Luis, Sonora.

gracilior group

* Paruroctonus gracilior (Hoffmann, 1931)
Distribution: Throughout and mostly restricted to the Chihuahuan Desert Region of North America in southeastern *Arizona, southern *New Mexico, and throughout the Trans-Pecos Region of *Texas.
Mexico: Aguascalientes and Coahuila. Fairly common.
Notes: Paruroctonus gracilior is the type species to the genus Paruroctonus. It is also a rather unique species and is the only species in its group (Haradon 1985).
Paruroctonus pallidus Williams, 1968 (from Cuatro Cienegas, Coahuila) is a junior synonym of P. gracilior, and is a pale psammophilic form of P. gracilior.
Other photos:
Female P. gracilior, assuming position!
Ventral aspect of adult male P. gracilior showing shape of male pectines (combs): note how the "teeth" touch.

stahnkei group

borregoensis subgroup

Paruroctonus ammonastes Haradon, 1984
Distribution: Arizona: Mohave County: Topock and Lake Havasu. Note: This species is apparently quite rare. Attempts to collect it in previously published localities have proven futile (Bigelow).

Paruroctonus borregoensis Williams, 1972
Photo courtesy of and Copyright Graeme Lowe.
Distribution: This species is found in sandy and desert habitats.
California: San Bernardino, Riverside, San Diego, and Imperial counties, essentially avoiding the Coachella Valley. Arizona: Yuma County. Mexico: Northwestern Sonora and northeastern Baja California Norte.

Paruroctonus hirsutipes Haradon, 1984
Distribution: California: Winterhaven, Imperial County. Arizona: Somerton, Yuma County.
Note: Rare, but occurs with P. xanthus in the Altar Dune System (Bigelow).

Paruroctonus luteolus (Gertsch and Soleglad, 1966)
Distribution: Nevada: Lincoln County. California: Inyo, San Bernardino, San Diego, and Riverside counties. Arizona: Dateland, Yuma County.
Fairly common.

shulovi subgroup

Paruroctonus shulovi shulovi (Williams, 1970)
Distribution: California: Inyo County, northern Death Valley at Grapevine Spring and Scotty’s Ranch.

Paruroctonus shulovi nevadae Haradon, 1985
Distribution: Nevada: Nye and Clark counties, near California border. California: Tecopa, Inyo County.

Paruroctonus simulatus Haradon, 1985
Distribution: Nevada: Mineral and Esmeralda counties. California: Eureka and Saline valleys, Inyo County.

stahnkei subgroup

Paruroctonus stahnkei (Gertsch and Soleglad, 1966)
Distribution: Northeastern Sonoran Desert. Arizona: Maricopa and Pima counties. Also in eastern Yuma County (Bigelow).

williamsi subgroup

* Paruroctonus pecos Sissom and Francke, 1981
Photo of female, courtesy W.D. Sissom, Copyright 2003 KJM.
Distribution: *New Mexico: *Lea and Eddy counties (*other specific localities not yet published). *Texas: Extreme western *Crockett County (other specific localities not yet published).

Paruroctonus williamsi Sissom and Francke, 1981
Distribution: Texas: Grapevine Hills, Big Bend National Park, Brewster County.
Extremely rare.
Note: Only one collection (by Joe L. Bigelow) of a few specimens is known. Repeated efforts to find this species since the first collection have proven futile.

Genus Smeringurus Haradon, 1983

This genus, previously a subgenus of Paruroctonus and raised to generic status by Stockwell in 1992, is characterized by randomly dispersed setae (hairs) on the ventral side of the metasoma (species of Paruroctonus have these setae arranged in ordered pairs) and their enormous size, compared to Paruroctonus.

Smeringurus aridus Soleglad, 1972
Distribution: California: Anza-Borrego Desert State Park, San Diego County.

*Smeringurus mesaensis Stahnke, 1957
Photo in link of adult male S. mesaensis courtesy of and Copyright 1999 R. David Gaban.
Distribution: *Arizona: La Paz, *Maricopa, S Mohave, and Yuma counties (Bigelow). California: San Bernardino, Riverside, San Diego, Kern, and Imperial counties.
Sonora and Baja California Norte, Mexico.
Abundant in most sand dunes within its range, although it is apparently not restricted to dune habitats (Bigelow).
Note: This species is unfortunately exploited for use in glass paperweights, belt buckles, magnets, bola ties, etc.

Smeringurus vachoni vachoni (Stahnke, 1961)
Distribution: Nevada: Clark County. California: Imperial, Riverside, Inyo, and San Bernardino counties.

Smeringurus vachoni immanis (Soleglad, 1972)
Distribution: Arizona: La Paz and Yuma counties. California: Imperial, Riverside, Inyo, and San Bernardino counties.

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