Pseudouroctonus m. castaneus
Pseudouroctonus m. thompsoni
Pseudouroctonus sprousei Francke and Savary 2006
Pseudouroctonus sprousei Francke and Savary 2006:
21–30, figs. 1-14 .
Francke and Savary 2006 - Holotype male from MEXICO: Coahuila; El Abra
(cave), El Remolino (UTM NAD27: 14R: 267620, 3180825, elev. S530 m.) [N 28o
44´ 0.5´´ W–101o 22´ 45´´] 29 April 2001, 17 Feb. 2002 (the specimen label
bears two dates, on both of which the cave was explored; the collector
indicated the second date is probably when the specimen was actually
collected). Peter Sprouse. Deposited in the Colección Nacional de Arácnidos
(CNAN T-0202), Departamento de Zoología, Instituto de Biología, Univ.
Nacional Autónoma de México.
Francke and Savary 2006:
"Diagnosis. Differs from
all other Pseudouroctonus species by having a distinct patellar
internomedian carina and by its large size, with the only adult specimen
known measuring 74 mm in length. Differs from P. lindsayi and the
species in the former minimus group in having a distinct white
patch on the pedipalp chela finger tips, in having prominent teeth
ventrally on the fixed and movable fingers of the chelicera, and in
having 17 pectinal teeth in males. Further differs from the members of
the former minimus group in lacking a distinctive tooth on the
lateral lobe of the lamellar hook of the hemispermatophore, and differs
from P. lindsayi in having the lamellar hook elevated from the
lamella base. It is most closely related to P. reddelli, the type
species of the genus, based on hemispermatophore morphology, cheliceral
dentition, pedipalps finger terminating in a white patch, and elevated
pectinal tooth count. Differs from P. reddelli in size, being
almost 50% larger; in color, being medium brown without fuscosity (P.
reddelli is dark reddish brown and heavily infuscate); in having
metasomal segment I clearly longer than wide (subequal in P. reddelli);
in having the pedipalp femur and patella longer than the carapace
(shorter or subequal in P. reddelli); and in bearing seven rows
of denticles clearly defined by six enlarged primary denticles on the
movable finger of the pedipalp chela (P. reddelli has six rows
defined by five primary denticles.
Description. Based on the adult holotype male and only known
specimen (Fig. 1).
Color: Medium brown; venter and legs ochre/yellow, without fuscosity.
Carapace: Longer than wide. Median eyes on anterior 35%. Ocular tubercle
low, without superciliary crests. Median eyes reduced in size, 0.2 mm in
diameter. Three pairs of lateral eyes, somewhat reduced in size;
posterior-most eye is about ½ diameter of anterior two. Anterior median
furrow shallow and broad. Posterior median furrow deep and narrow, the
median lobes meeting medially over the furrow. Posterolateral furrows
deep and broad. Anterior margin broadly bilobed, with 3 pairs of setae.
Entire surface with moderately dense, fine granulation.
Tergites: With moderately dense, fine granulation. Tergite VII with four
denticulate, longitudinal carinae .
Sternum: Subpentagonal, slightly longer than broad; median longitudinal
furrow deep and narrow; with seven setae (asymmetrical).
Genital operculi: With five setae each; genital papillae well developed,
protruding beyond the genital operculi.
Pectines: With 10–11 middle lamellae; 17 teeth on each side.
Sternites: Glabrous. Stigmata slit-like, about 3.5 times longer than
wide. Sternite VII with one pair of moderately strong, denticulate
Metasoma: Dorsolateral carinae on I–V strong, denticulate/serrate.
Lateral supramedian carinae on I–IV strong, denticulate/serrate. Lateral
inframedian carinae on I strong, denticulate, complete; on II
represented by 3–4 granules distally; on III by one single granule
distally; on IV absent. Lateral median carina on V granular on basal
one-third. Ventrolateral carinae on I–V, ventral submedian carinae on
I–IV and ventral median carina on V strong, denticulate/serrate.
Setation on I–IV: dorsolaterals 0,1,1,2; lateral supramedian 0,1,1,1;
lateral inframedian 1,0,0,0; ventrolateral 2,2,2,3; ventral submedian
3,3,3,4. Setation on V: dorsolateral 3, lateromedian 2, ventrolateral 3
and ventromedian 4. Intercarinal spaces densely, minutely granulose
Telson: Vesicle large and globose (Fig. 2), more swollen than that of
P. reddelli (Fig. 3); weakly to faintly granulose, sparsely setose.
Aculeus lacking basal microdenticles.
Chelicera: Fixed finger shorter than chela width, movable finger shorter
than chela length. Chela with 2 setae dorsally. Fixed finger with basal
bicusp symmetrical; ventral margin with 3 prominent accessory denticles
(Fig. 4). Movable finger with two dorsal subdistal teeth; with a
distinct serrula ventrally, and with ventral carina strongly delineated,
bearing three large and several small denticles (Fig. 4).
Pedipalp femur: Dorsointernal, dorsoexternal and ventrointernal carinae
strong, coarsely granulose; ventroexternal carina obsolete;
internomedial carina represented by 4–5 isolated granules which decrease
in size distally. Orthobothriotaxia “C” (Fig. 5). Dorsal face with
dense, small granulation; internal face with three submedian setae;
external face with four median setae; ventral face with moderately dense
granulation, decreasing in size distally.
Pedipalp patella: Internomedian carina represented by a row of 7–8
prominent granules spread on basal two-thirds, decreasing in size
distally and angling slightly dorsally; dorsointernal carina strong,
coarsely granulose; dorsoexternal carina strong, scabrose;
ventrointernal carina strong, coarsely granulose; ventroexternal carina
strong, scabrose. Orthobothriotaxia “C” (Figs. 6–8). Intercarinal spaces
dorsally matte, matte to glabrous on others.
Pedipalp chela: Carinae scabrous to granulose; intercarinal spaces
lustrous. Finger tips with distinctive white patches distally. Fixed
finger with 6 rows of granules and 6 inner accessory denticles; movable
finger with 7 rows of granules and 7 inner accessory denticles.
Orthobothriotaxia “C” (Figs. 9–11).
Leg III telotarsal armature (Figs. 12–14): two prolateral inframedian
setae; two retrolateral inframedian setae; two prolateral infraterminal
setae; two retrolateral infraterminal setae. Ventral median spinules:
basal cluster, distally with 4–5 spinules.
Hemispermatophore: with dorsal hook on basal 28% of lamina (Fig. 15).
Bears a thickened, acuminate lateral hook connected to the lamella by an
elevated lateral flange (Figs. 16–17); mating plug with distal barb
margin smooth (Fig. 18). Resembles that of P. reddelli (Figs.
Measurements (in mm). Total L 74.1; carapace L/W 8.6/7.0; distance
from anterior margin to median eyes 3.2; mesosoma L 18.4; metasoma total
L 47.1; segment I L/W 5.0/3.6; II L/W 6.0/3.4, III L/W 6.3/3.2; IV L/W
7.8/3.0; V L/W/D 11.8/2.8/2.5; telson L/W/D 10.2/3.2/3.3; chelicera L/W
3.4/1.8, fixed finger L 1.0, movable finger L 2.0; pedipalp femur L/W
9.2/2.4; pedipalp patella L/W 9.2/2.6; pedipalp chela L/W/D
15.6/3.5/4.3, fixed finger L 6.2, movable finger L 7.6.
Hemispermatophore L 8.0, lamina L 5.0."
AMERICA. México: (Coahuila: El Abra (cave), El Remolino). Possibly
also in Los Ojos Cave.
Known in the literature only from type.
sprousei has median and lateral eyes (these somewhat reduced in size),
so it has not reached the extreme condition of eyelessness observed in other
Mexican cave scorpions (e. g., some Typhlochactas Mitchell,
Sotanochactas Francke, Troglocormus Francke, and Alacran
Francke). Although P. reddelli has been collected in numerous caves
(as well as many surface locations) in Texas and Coahuila, it has no
apparent morphological modifications for life in caves. It is hypothesized
that P. sprousei is troglobitic when compared to P. reddelli,
its putative closest relative: it is considerably paler in color; the
metasoma is elongated [apparent when the length/width ratio of segment I
(close to 1.5 in P. sprousei ) is compared to that of P. reddelli
(approximately equal to 1)]; and the pedipalps are attenuated [apparent
when the relative lengths of the femur and patella are compared with the
carapace length in the two sister species—subequal in P. reddelli and
longer in P. sprousei]. This hypothesis awaits further testing by the
collection of additional specimens and data on their habitat and biology.
This species is dedicated to Mr. Peter Sprouse, a
tireless explorer of Mexican caves and collector of numerous troglobites,
including the holotype of this taxon.
P. sprousei (?) from Los Ojos Cave, Coahuila, Mexico