Table Of ContentSYSTEMATIC REVISION OF THE
NORTH AMERICAN SYNTROPINE VAEJOVID
SCORPION GENERA BALSATERES, KUARAPU, AND
THORELLIUS, WITH DESCRIPTIONS OF THREE
NEW SPECIES
EDMUNDO GONZÁLEZ-SANTILLÁN
City University of New York;
Scorpion Systematics Research Group, Division of Invertebrate Zoology,
American Museum of Natural History;
Current address: Instituto de Biotecnología,
Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
Facultad de Ciencias, Departamento de Biología Comparada,
Universidad Nacional Autonóma de México, Mexico City
LORENZO PRENDINI
Scorpion Systematics Research Group,
Division of Invertebrate Zoology,
American Museum of Natural History
BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY
Number 420, 81 pp., 36 figures, 8 tables
Issued June 20, 2018
Copyright © American Museum of Natural History 2018 ISSN 0003-0090
CONTENTS
Abstract.............................................................................3
Introduction.........................................................................3
Taxonomic History...................................................................4
Material and Methods ................................................................8
Systematics..........................................................................9
Balsateres González-Santillán and Prendini, 2013.........................................9
Balsateres cisnerosi (Ponce-Saavedra and Sissom, 2004)...................................12
Kuarapu Francke and Ponce-Saavedra, 2010 ............................................17
Kuarapu purhepecha Francke and Ponce-Saavedra, 2010..................................21
Thorellius Soleglad and Fet, 2008 ......................................................26
Key to Identification of the Species of Thorellius.........................................27
Thorellius cristimanus (Pocock, 1898) ..................................................28
Thorellius intrepidus (Thorell, 1876)....................................................39
Thorellius tekuani, sp. nov.............................................................48
Thorellius wixarika, sp. nov...........................................................60
Thorellius yuyuawi, sp. nov............................................................72
Acknowledgments...................................................................78
References..........................................................................79
2
ABSTRACT
Four genera formed a monophyletic group, referred to as the Kochius clade, in the phylogeny
of the North American vaejovid scorpion subfamily Syntropinae Kraepelin, 1905: Balsateres
González-Santillán and Prendini, 2013; Kochius Soleglad and Fet, 2008; Kuarapu Francke and
Ponce-Saavedra, 2010; and Thorellius Soleglad and Fet, 2008. In the present contribution, all
except Kochius, treated elsewhere, are revised. The monotypic Balsateres and Kuarapu are rede-
scribed. Thorellius cristimanus (Pocock, 1898) and Thorellius intrepidus (Thorell, 1876) are rede-
scribed and their type localities discussed and clarified. Three new species of Thorellius are
described: Thorellius tekuani; Thorellius wixarika; and Thorellius yuyuawi. Vaejovis intrepidus atrox
Hoffmann, 1931, is newly synonymized with T. cristimanus based on examination of the type
material. A key to identification of the species of Thorellius is presented, and new locality records
and updated distribution maps provided for all species covered.
INTRODUCTION México, western Guanajuato, and southern
Zacatecas (figs. 2–4). Balsateres and Kuarapu are
Four genera formed a monophyletic group, relatively stenotopic. Balsateres cisnerosi Ponce-
referred to as the Kochius clade, in the phylog- Saavedra and Sissom, 2004, which burrows in
eny of the North American vaejovid scorpion sandy river beds (Ponce-Saavedra and Sissom,
subfamily Syntropinae Kraepelin, 1905, pre- 2004), is semipsammophilous, possessing a pale
sented by González-Santillán and Prendini and glabrous integument without metasomal
(2015a): Balsateres González-Santillán and carinae, but lacks setal combs on the leg tarsi, a
Prendini, 2013; Kochius Soleglad and Fet, 2008; psammophilous characteristic (Prendini, 2001).
Kuarapu Francke and Ponce-Saavedra, 2010; Kuarapu purhepecha Francke and Ponce-Saave-
and Thorellius Soleglad and Fet, 2008 (fig. 1). dra, 2010, usually found actively foraging on the
Members of this clade are united by low setal surfaces of road cuts at night or resting in rock
counts on the dorsolateral and ventrosubme- piles by day, is lithophilous, with slender pedi-
dian carinae of metasomal segment IV and the palps and a somewhat dorsoventrally compressed
granular condition of the pro- and retrolateral soma. Thorellius species are eurytopic and pre-
carinae of the pedipalp femur, the ventral dominantly lapidicolous. Although often shelter-
median carina of the patella, and the median ing under stones, logs or other available debris,
and retrolateral carinae of the chela (González- where they may excavate shallow burrows,
Santillán and Prendini, 2015a: 403, appendix 9). Thorellius also inhabits the cracks and crevices of
These characters distinguish the four genera rocks. Thorellius includes the largest species in
from all other genera in the subfamily. family Vaejovidae Thorell, 1876, with females
Whereas Balsateres and Kuarapu are mono- attaining a length of 94 mm (Sissom, 2000).
typic, Kochius and Thorellius are mesodiverse. In the present contribution, all except Kochius,
Species of Kochius inhabit desert to semidesert to be treated elsewhere, are revised in accordance
habitats from the Baja California Peninsula and with the classification, terminology, and homol-
the Mexican state of Sonora to the states of Ari- ogy assessment proposed by González-Santillán
zona, California, and Nevada (González-Santil- and Prendini (2013, 2015a, 2015b). The mono-
lán and Prendini, 2015a). In contrast, species of typic Balsateres and Kuarapu are redescribed.
Balsateres, Kuarapu, and Thorellius are endemic Thorellius cristimanus (Pocock, 1898) and Thorel-
to Mexico and inhabit tropical deciduous forest lius intrepidus (Thorell, 1876) are redescribed
throughout the Balsas Basin, and along the and their type localities discussed and clarified.
Pacific coast from the states of Nayarit to Guer- Three new species of Thorellius are described:
rero, southern Aguascalientes and Estado de Thorellius tekuani, sp. nov.; Thorellius wixarika,
3
4 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 420
FIGURE 1. Habitus in life. A. Balsateres cisnerosi (Ponce-Saavedra and Sissom, 2004), ♀; B. Kuarapu purhepe-
cha Francke and Ponce-Saavedra, 2010, ♀; C. Thorellius cristimanus (Pocock, 1898), ♂; and D. Thorellius
intrepidus (Thorell, 1876), ♀.
sp. nov.; Thorellius yuyuawi, sp. nov. Vaejovis In face of Thorell’s description, I find it
intrepidus atrox Hoffmann, 1931, is newly syn- impossible to adopt this opinion [Kraepe-
onymized with T. cristimanus based on examina- lin’s (1894, 1899) recognition of Vaejovis
tion of the type material. A key to identification intrepidus as type species of the genus]. The
of the species of Thorellius is presented, and new measurements given show that V. intrepidus
locality records and updated distribution maps is about twice the size of the average V.
provided for all species covered. mexicanus, the length being 84, the cara-
pace 11.5, and the tail 52.5 mm. Moreover,
the third caudal segment is one-third longer
TAXONOMIC HISTORY
than wide (9:6) and the second as long as
Two species presently accommodated in wide. Lastly, the inferior caudal keels,
Thorellius, including the type species of the although well expressed, are described as
genus, T. intrepidus, were originally placed in the subgranular, except the median keels on
“catchall” genus Vaejovis C.L. Koch, 1836. Thorell segment 1, 2, and 3, which are smooth,
(1876a, 1876b, 1877) mistakenly regarded Vejovis those on the third being subgranular only
intrepidus Thorell, 1876, rather than Vaejovis posteriorly. So far as these keels are con-
mexicanus C.L. Koch, 1836, as the type species of cerned, as well as in color and certain other
Vaejovis. Whereas Kraepelin (1894, 1899) fol- characters, V. intrepidus, apart from its
lowed Thorell’s (1876a, 1876b, 1877) opinion, much greater size, most nearly approaches
Pocock (1902: 13) disagreed: V. cristimanus…
2018 GONZÁLEZ-SANTILLÁN & PRENDINI: REVISION BALSATERES, KUARAPU, AND THORELLIUS 5
FIGURE 2. Map of central Mexico, plotting known locality records for the vaejovid scorpion species, Bal-
sateres cisnerosi (Ponce-Saavedra and Sissom, 2004) (triangles) and Thorellius cristimanus (Pocock, 1898)
(squares), based on data collected in the present study.
Hoffmann (1931) divided Vaejovis into three Vaejovis cristimanus Pocock, 1898, demoted to
“sections” and recognized the differences subspecies, establishing Vaejovis intrepidus
between V. intrepidus and V. mexicanus noted by cristimanus Pocock, 1898. Despite noting “he
Pocock (1902). Hoffmann’s (1931) “second sec- reunido tres formas que por sí sola cada una
tion” was the precursor of the intrepidus group of puede pasar por especie propia” (I reunited
Vaejovis (Sissom, 1989) to which the name three forms that each can be recognized as a
Thorellius was later assigned (Soleglad and Fet, proper species), Hoffmann (1931: 374) consid-
2008) whereas Hoffmann’s (1931) “third section” ered differences in the trichobothrial counts
became the mexicanus group (Soleglad, 1973), among these “forms” to represent intraspecific
currently what remains of Vaejovis, in the nomi- variation, associated with differences in habi-
notypical subfamily Vaejovinae Thorell, 1876 tat and climate.
(Soleglad and Fet, 2008). In addition to V. intrepidus and its subspecies,
Hoffmann (1931) recognized three “forms” Hoffmann’s (1931) second section of Vaejovis
within V. intrepidus: the nominotypical form; included the nominotypical form of Vaejovis
Vaejovis intrepidus atrox Hoffmann, 1931; and subcristatus Pocock, 1902, and V. subcristatus
6 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 420
FIGURE 3. Map of central Mexico, plotting known locality records for the vaejovid scorpion species, Thorellius
tekuani, sp. nov. (triangles), and Thorellius wixarika, sp. nov. (circles), based on data collected in the present study.
occidentalis Hoffmann, 1931. Sissom (1989) later and Kochius, respectively, and transferred Thorel-
elevated V. occidentalis to the rank of species and lius to subtribe Thorelliina Soleglad and Fet,
suggested a possible link between the former 2008, of tribe Syntropini Kraepelin, 1905. In
intrepidus group of Vaejovis and the former addition to renaming the intrepidus group
punctipalpi group, created by Williams (1971), to Thorellius, Soleglad and Fet (2008) elevated the
which the name, Kochius, was later assigned two subspecies of T. intrepidus to the rank of spe-
(Soleglad and Fet, 2008). cies, creating Thorellius atrox (Hoffmann, 1931)
Vaejovis intrepidus and its subspecies, along and T. cristimanus, and transferred Vaejovis cis-
nerosi Ponce-Saavedra and Sissom, 2004, to
with V. occidentalis and V. subcristatus, remained
Thorellius. In the original description of V. cis-
in the intrepidus group for several decades (Lou-
nerosi, Ponce-Saavedra and Sissom (2004: 540)
renço and Sissom, 2000; Sissom, 2000) until
refrained from assigning it to any of the species
Soleglad and Fet (2008) presented their revised
groups recognized at that time due to its unique
classification of Vaejovidae. Soleglad and Fet
character combination:
(2008) formalized the relationship between the
intrepidus and punctipalpi groups, suggested ear- Vaejovis cisnerosi is unlike all other spe-
lier by Sissom (1989), renamed them Thorellius cies of Vaejovis in that the carinae of the
2018 GONZÁLEZ-SANTILLÁN & PRENDINI: REVISION BALSATERES, KUARAPU, AND THORELLIUS 7
FIGURE 4. Map of central Mexico, plotting known locality records for the vaejovid scorpion species, Kuarapu
purhepecha Francke and Ponce-Saavedra, 2010 (square), Thorellius intrepidus (Thorell, 1876) (triangles) and
Thorellius yuyuawi, sp. nov. (circle), based on data collected in the present study.
dorsal and lateral surfaces of the meta- lets (Sissom, 1991) [spinose distal barb
soma are greatly reduced in strength margin]. The position of trichobothria ib
(mostly obsolete) and completely smooth. and it on the pedipalp chela fixed finger
In addition, the metasomal setation is (displaced to near the 6th inner accessory
highly reduced … giving it the lowest setal denticle of the primary denticle row) and
counts of any species in the genus. These the possession of only five subrows of den-
features are autapomorphic.… The hemi- ticles on the chela fixed finger also suggest
spermatophore of V. cisnerosi is quite sim- relationship with those groups. Finally, the
ilar to those of the species of the V. ventromedian spinule row of the leg tarsi
eusthenura, V. intrepidus and V. puncti- are flanked distally by two or more pairs
palpi species groups. There is a broad of larger spinules, as in the aforemen-
flange along the ental margin of the distal tioned groups. The reduction of the cari-
lamina [fused margin of dorsal and ven- nae of the pedipalps and the absence of
tral troughs], and the ental process of the ventral carinae on the metasoma place the
inner capsular lobe bears a series of hook- species closer to the eusthenura group
8 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 420
(e.g., in southern Mexico, this would when tested by a quantitative phylogenetic analy-
include Vaejovis punctatus Karsch, 1879 sis based on morphological characters and DNA
[currently Mesomexovis punctatus (Karsch, sequences from the nuclear and mitochondrial
1879)] and its relatives); on the other genomes (González-Santillán and Prendini,
hand, the reduction of the metasomal 2015a). Thorellius, as defined by Soleglad and Fet
setation and the dorsoventral compression (2008), was consistently polyphyletic, and the
of the metasoma are similar to the condi- group comprising T. atrox, T. cristimanus, and T.
tions seen in the intrepidus species group. intrepidus consistently monophyletic. In conse-
quence, Thorellius was restricted to these species,
Soleglad and Fet (2008: 95) justified the trans-
and the other species transferred to different gen-
fer of V. cisnerosi to Thorellius, despite the uncer-
era by González-Santillán and Prendini (2013).
tainty regarding its phylogenetic placement
Balsateres was created to account for the phyloge-
(Ponce-Saavedra and Sissom, 2004), and without
netic position and unique diagnostic character
testing that placement in a quantitative analysis,
combination of V. cisnerosi, creating B. cisnerosi,
as follows:
whereas V. occidentalis and V. subcristatus were
transferred to Mesomexovis, creating Mesomexovis
Clearly the hemispermatophore, with its
occidentalis (Hoffmann, 1931) and Mesomexovis
well developed lamellar hook [fused mar-
subcristatus (Pocock, 1902).
gin of dorsal and ventral troughs], the
Francke and Ponce-Saavedra (2010) discussed
mating plug with its toothed barb [spi-
the placement of Kuarapu in the context of
nose distal barb margin], and the multiple
Soleglad and Fet’s (2008) classification, and
pairs of ventral distal spinules of the leg
offered two alternatives: placement within Syn-
tarsus imply this species is a member of
tropini, based on the spinose distal barb margin
tribe Syntropini. The chelal and meta-
of the hemimating plug of the male hemisper-
somal carination of this species is
matophore, peg sensillae on the basal pectinal
unique… where the former exhibits vesti-
teeth of the female, and five ventral spinules on
gial to smooth carinae and the ventral
the telotarsus of leg III; or within Stahnkeini
carinae of the latter are obsolete. The exis-
Soleglad and Fet, 2008, based on the shared ser-
tence of carinae on the chelae, though
rate cutting edge of the pedipalp chela fingers
smooth, and the somewhat robust chelae
and the medial position of trichobothria ib and
imply this species is a member of subtribe
it on the pedipalp chela fixed finger. The analyses
Thorelliina. The carapace in T. cisnerosi
of González-Santillán and Prendini (2015a) con-
lacks the anterior emargination extending
firmed the first hypothesis, based on the spinose
to the lateral ocelli as seen in Kochius and
distal barb margin of the hemimating plug,
the placement of chelal trichobothrium
uniquely synapomorphic for Syntropinae, and
Dt is well distal of the palm midpoint,
consistently recovered Kuarapu as the basal
indications of genus Thorellius... Finally,
member the Kochius clade.
of somewhat less importance, the large
size of this species, its large pectinal tooth
count (20–22 for males and 20–21 for MATERIAL AND METHODS
females), and its geographical distribution
Scorpion specimens were collected mostly by
also indicates genus Thorellius.
ultraviolet (UV) light detection at night using
As discussed by González-Santillán and Pren- portable UV lamps, comprising mercury vapor
dini (2013), most of the new taxa proposed in the tubes attached to a chromium reflector, and pow-
classification presented by Soleglad and Fet (2008) ered by a 12V, 7 amp/hour battery, or Maglite
were demonstrably paraphyletic or polyphyletic flashlights modified with UV light-emitting
2018 GONZÁLEZ-SANTILLÁN & PRENDINI: REVISION BALSATERES, KUARAPU, AND THORELLIUS 9
diode (LED) attachments. Some specimens were North America, generated from digital elevation
collected during the day by turning rocks and model files with 1 arc degree of resolution, obtained
other objects on the ground. from the United States Geological Survey.
Material examined is deposited in the follow-
ing collections: American Museum of Natural
History, New York (AMNH), including tissue SYSTEMATICS
samples stored in the Ambrose Monell Cryocol-
FAMILY VAEJOVIDAE THORELL, 1876
lection (AMCC); Natural History Museum, Lon-
don (BMNH); Colección Nacional de Arácnidos Subfamily Syntropinae Kraepelin, 1905
(CNAN), Instituto de Biología, Universidad
Nacional Autónoma de México (IBUNAM), Mex- Balsateres González-
ico City; Instituto Nacional de Diagnostico y Ref- Santillán and Prendini, 2013
erencia Epidemiologicos, Mexico City (INDRE);
Figures 5, 8, 9–15; table 8
Naturhistoriska Riksmuseet, Stockholm, Sweden
(NRS); Universidad Michoacana de San Nicolás Vaejovis cisnerosi Ponce-Saavedra and Sissom,
de Hidalgo, Morelia, Mexico (UMSNH). Speci- 2004 [= Balsateres cisnerosi (Ponce-Saavedra
mens at the AMNH and CNAN bearing ARA and Sissom, 2004)], type species by
(Arachnida) numbers were collected during a U.S. monotypy.
National Science Foundation–funded “Revision- Vaejovis incertae sedis Ponce-Saavedra and Sis-
ary Syntheses in Systematics” grant. som, 2004: 541.
The sex and life stage of specimens were Thorellius: Soleglad and Fet, 2008: 53, 58, 67, 77,
determined by pectinal tooth counts, the pres- 94, 95, tables 4, 9.
ence or absence of genital papillae, secondary Balsateres González-Santillán and Prendini,
sexual characters, and the presence of hemisper-
2013: 3, 6, 7, 18, 24, 53, 59, table 1, figs. 3;
matophores or mature ovariuteri. Morphological
2015a: 349, 351, 352, 355, 356, 360, 362,
terminology follows González-Santillán and
363, 367, 372, 403, fig., table 5, 6; Quijano-
Prendini (2013). Hemispermatophores were
Ravel and Ponce-Saavedra, 2014: 17, 18,
cleared by hand or with clove oil. Measurements
table 2; 2016: 50; Santibáñez-López et al.,
(mm), following Sissom et al. (1990), were taken
2015: 7; Dupré, 2017: 9.
with an ocular micrometer and illustrations of
external morphology produced using a Nikon Diagnosis: Balsateres may be distinguished
SMZ 1000 or 1500 stereomicroscope with a cam- from other genera of Syntropinae by the smooth
era lucida. Morphometric ratios, expressed as dorsal lateral and lateral median carinae of meta-
means, are given separately for adult males and somal segments I–V. The carinae and intercarinal
females. Digital images were taken under visible surfaces of the carapace, pedipalp chela and patella,
and UV light using a Microptics ML1000 digital tergites, metasoma, and telson are smooth (figs. 5A,
imaging system. Photographs and illustrations 9A, 10A, 11A, 17, 18, 19) unlike other syntropine
were edited using Adobe Photoshop CS5. genera, in which they are granular. Counts of mac-
Collection localities were georeferenced in the rosetae on the carinae of metasomal segments I–IV
field with portable GPS devices (Garmin® V Plus) are also greatly reduced in Balsateres, compared
or retroactively using GEOLocate (Rios and Bart, with other syntropine genera as follows: dl,
2010) and Google Earth version 6.1.0.5001. Distri- 0/0:0/0:0/0:1/1:4/4; lm, 0/0:0/0:0/0:0/0:2/2; vl and
bution maps were generated using ArcMap 9.3.1 vsm, 1/1:1/1:1/1:1/1:3/3. Two or more macrosetae
(Environmental Systems Research Institute, Red- are present on these carinae in other syntropine
lands, California), by superimposing point locality genera, including Thorellius, which also presents
records on layers depicting the topography of low setal counts, e.g., the following counts on seg-
