Paruroctonus xanthus (Gertsch & Soleglad 1966)
Vejovis (Paruroctonus)) xanthus
►Gertsch & Soleglad, 1966: 34.
Paruroctonus xanthus: Williams, 1972: 3; Soleglad, 1973b: 355;
Williams, 1976: 2; ►Williams, 1980: 32, 46, fig. 36E, 37E; Haradon,
1984a: 210; Haradon, 1984b: 318; Haradon, 1985: 24, 40; Kovarík, 1998:
144; Beutelspacher, 2000: 70, 136, 146, 152, map 42; Sissom,
Vejovis (Paruroctonus) xanthus Gertsch & Soleglad
female holotype from 13 miles (21 km) west of Winterhaven, Imperial County,
California, USA, June 13, 1958 (V. Roth). Deposited in the American Museum
of Natural History.
Gertsch & Soleglad 1966:
DIAGNOSIS: Pale scorpion resembling auratus and
mesaensis in appearance and sharing features of both. Median eyes of
medium size and set well in advance of center of carapace. Cauda stout
and bearing only up to five pairs of setae on inferior median keels.
Telson long and slender and bearing a long, lightly curved sting.
Pedipalps resembling those of mesaensis, but stout fingers
proportionately longer and more deeply scalloped.
COLORATION: Entire body pale yellow to golden orange, without
contrasting markings except as follows: Lateral eyes and small tubercles
black. Median eyes and most of tubercles black. Articulation spots on
appendages red. Tip of sting red. Dark setae on appendages with reddish
STRUCTURE: Similar to that of boreus except as noted below. Measurements
given in table 5.
Carapace: Anterior margin essentially straight (fig. 19), set with six
short setae; sides gently scalloped; width at rounded caudal margin
equal to length. Median eyes well in front of middle of carapace, of
medium size, set on small elevated tubercles; width of median diad about
one-fourth of width of carapace at that point (23/96). Granulation
inconspicuous because of pale color but heavier than that of boreus.
Preabdomen: Smooth, shining, with quite typical armature of granules as
Cauda: Stouter than that of boreus but sculptured essentially as in that
species. Dorsal and superior lateral keels prominent, crenulate, with
rounded or pointed granules. Inferior lateral keels distinct on all
segments, weakly denticulate on segment I, nearly smooth, with scattered
denticles, on segment II, smooth, with more numerous denticles, on
segment III, quite regularly denticulate on segment IV, and evenly set
with pointed granules on segment V. Inferior median keels of segments
I-III distinct but smooth, of segment IV with granules in distal fifth
of length; single median keel of segment V with closeset series of sharp
granules. Segments I-IV with 3-4-4-5 pairs of setae on median keels.
Telson: Details as shown in figure 71. Vesicle slender, quite smooth,
set with fine bristles; sting long, moderately curved; subaculear nodule
of medium development.
Pectines: Similar to those of boreus. Pectinal teeth 21/22.
Chelicerae: Similar to those of boreus. Lower margin of fixed finger
with two nodules near base. Lower margin of movable finger with keel
dissected into six or seven irregularly formed denticles. Apical tooth
on lower margin of movable finger stout, nearly equal to opposing apical
Pedipalps: Similar to those of mesaensis, with smaller and stout, long
fingers as shown in figure 32. All carinae conspicuous and set with
quite coarse, pale granules. Inner keels of fingers quite deeply
Walking legs: First to third protarsi with regular series of nine to 12
long, stout bristles on dorsal surface; fourth protarsus with five
Diagnosis. Adults to 65 mm long. Entire body
pale yellow to golden-orange, lacking contrasting dark color markings.
Metasoma with distinct ventrolateral keels on all segments, these weakly
denticulate on segment I, nearly smooth with few scattered denticles on
II, smooth with more numerous denticles on III, regularly denticulate on
IV; metasoma with ventromedian keels of segments I-III distinct but
smooth, segment IV with granules along distal fifth of keels: space
between ventromedian keels not hirsute: pectine teeth 19-23 in females,
28-32 in males: chelicerae with ventral margin of fixed finger armed
with two small denticles near base; ventral margin of movable finger of
chelicerae with 6 or 7 irregularly formed denticles; pedipalps with
relatively long fingers, fixed finger longer than palm, movable finger
longer than carapace or metasomal segment V; pedipalp palm with granular
Similar to P. mesaensis and P. auratus. Differs from P.
mesaensis as follows: lack of abundant bristles between ventromedian
keels of metasoma; metasomal segment I approximately as long as wide
(not longer than wide); fixed finger of pedipalp distinctly longer than
palm or metasomal segment V. Differs from P. auratus as follows:
pedipalp fixed finger longer than carapace or metasomal segment V.
AMERICA. México (Sonora), USA
(California). Per Williams (1980): "Sand
dunes where borders of Baja California, California, and Arizona intersect. Never reported from Baja California, but probably occurs there."
Mexico: 42 km E San Luis, 4-VI-1968 (Cazier, Bigelow. Davidson).