ARACHNOLOGY (EPWS
451/551)
INSTRUCTOR: David B.
Richman
Office: Arthropod Museum
ARACHNOLOGY
(EPWS 451)
Skeen Hall W 168
Photo by D. Richman
Texts


Foelix, R. F. 1996. Biology of Spiders, 2nd
Ed.
Ubick, D., P. Paquin, P. E. Cushing, and V.
Roth, 2005. Spiders of North America: An
Identification Manual.
Recommended Supplementary
Texts



Jackman. J. A. 1997. A Field Guide to Spiders
and Scorpions of Texas. (Updated classification)
Polis, G. A. 1990. The Biology of Scorpions
(Excellent treatment of scorpion biology)
Cloudsley-Thompson, J. L. 1968. Spiders,
Scorpions, Centipedes and Mites. (A bit dated,
but good biological data on all the arachnid
orders, plus centipedes and millipedes)
Internet Sources for Arachnida
http://www.arachnology.be/Arachnol
ogy.html
This is THE major beginning site for
all World Wide Web internet sites
If a site is not listed here, it probably
is not worth visiting
Photo Sources for Arachnida
I thank the following photographers for making their work available for
this course outline

C. Scott Bundy, Las Cruces, New Mexico

Pete Carmichael, Florida

Rob Curtis, Chicago, Illinois

Jillian Cowles, Tucson, Arizona

G. B. Edwards, Gainesville, Florida

Jon Reiskind, Gainesville, Florida

Simone Ross, Barrie, Ontario, Canada

W. David Sissom, Canyon, Texas

Lynn McCutchen, Kilgore, Texas
All other photos were taken by David B. Richman
OUTLINE: I
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Introduction- Outline of class
The Arachnida: Their place in the arthropod line
The orders and families of non-spider Arachnida
The biology of spiders
The taxonomy of spiders
Photo by D. Richman
OUTLINE: II- ORDERS of
ARACHNIDA
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Scorpiones
Opiliones
Uropygi
Amblypygi
Palpigradi
Schizomida
Solifugae
Pseudoscorpiones
Acari
Recinulei
Araneae
Photo by D. Richman
OUTLINE: III- Units of
Systematics
Class
Order
Family
Genus
Species
Photo by D. Richman
Arachnida: Their place in the
arthropod line – I
The Phylum Arthropoda was thought to consist of
two main phylogenetic lines
 The Mandibulata (including insects, crustaceans,
centipedes, millipedes, symphylans and
pauropods)
 The Chelicerata (including arachnids,
merostomates, sea scorpions an d sea spiders)
 Arthropods were closely related to annelid worms
and could possibly be polyphyletic (more than
one non-arthropod ancestor for the two main
lines)
Arachnida: Their place in the
arthropod line – II
It is now thought that this classification is
wrong and that:
 Crustacea plus Insects forms one clade
 The Chelicerata plus Myriapods
(centipedes, millipedes, symphylans)
forms a second clade
 The Arthropoda is monophyletic and
NOT related to Annelida!
Arachnida: Their place in the
arthropod line – III


The Chelicerata consists of three groups- the
sea spiders (affinities unknown, other than the
fact they are chelicerate), the merostomates
and the arachnids
The scorpions are somewhat problematic in
that they appear to be related to sea scorpions,
which have usually been placed with the
merostomates, but at the same time have
characteristics that unite them with the
harvestmen (Opiliones)
Arachnida: Their place in the
arthropod line – IV
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Sea spiders (Pycnogonida) are one of two groups of chelicerates that
are found in the world’s oceans
They may not in fact, be true chelicerates
Sea spiders have been collected in the abyssal regions and very large
ones live in deep water of Antarctica
These differ from all other
chelicerates in their structure,
lacking a well developed
abdomen
Males have ovigerous legs
where eggs are deposited
by the female
Arachnida: Their place in the
arthropod line – V
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Merostomates include the Xiphosaura (horseshoe crabs)
and possibly the Eurypterida (discussed under scorpions)
Horseshoe crabs are all marine and are often very
numerous
Their harvest for fertilizer, etc., along with pollution has
reduced their numbers in recent years
All have book gills, compound eyes and a long spike-like
telson
Horseshoe crabs are very ancient, dating back at least to
the Silurian
Arachnida: Their place in the
arthropod line – VI
Atlantic Horseshoe Crab
(Limulus polyphemus)
mating pair on Seahorse
Key, Levy County,
Florida
Photo by D. Richman
Arachnida: Their place in the
arthropod line – VII
A fossil Eurypterid
Silurian
Photo by D. Richman
ORDERS of ARACHNIDA I
Numbers of extant species
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Scorpiones – 1259 species (Fett et al. 2000)
Opiliones – 6085 species (Hallan 2001)
Uropygi – 98 species (Hallan 2001)
Amblypygi – 132 species (Hallan 2001)
Palpigradi – 71 species (Hallan 2001)
Schizomida – 9 species (Hallan 2001)
Solifugae – 900 species (Puzo 1998) 1074 species (Hallan 2001)
Pseudoscorpiones- 3064 species (Hallan 2001)
Acari –50,000 species (Hallan 2001)
Recinulei – 71 species (Hallan 2001)
Araneae – ca. 40,000 species (Platnick 2000-2002, Hallan 2001)
TOTAL 101,689 described species worldwide
ORDERS OF ARACHNIDA II:
SCORPIONES I
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
Order very ancient, dating back at least to to the
Silurian (over 400 million years ago) apparently
as aquatic forms with gills and compound eyes,
but no tarsal claws
By the Devonian (ca. 400 million years ago)
scorpions were at least in part terrestrial and by
the Carboniferous (350 million years ago)
virtually indistinguishable from modern scorpions
ORDERS OF ARACHNIDA II:
SCORPIONES II
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
Compound eyes were lost except for
cluster of simple eyes at front corners of
carapace
Scorpions are now considered to be closely
related either to the harvestmen (Opiliones)
or to the extinct Eurypterida (often placed
with the horseshoe crabs in the Class
Merostomata).
ORDERS OF ARACHNIDA:
II. SCORPIONES III


The Eurypterida, or “Sea Scorpions”
included the largest chelicerates (or even
arthropods) known, reaching up to 180 cm
in total length. All were aquatic, living in
fresh to brackish water from the
Ordovician to the Permian
The last of the eurypterids died out in the
extinction event at the end of the Permian
ORDERS OF ARACHNIDA:
II. SCORPIONES IV
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Scorpions are primarily nocturnal
Members of the class have adapted to life
in dry deserts and tropical forest; none live
in the Arctic or Antarctic
All are general predators, grasping their
prey with their claw-like pedipalpi and
stinging it with a venomous stinger at the
end of the post abdomen
ORDERS OF ARACHNIDA:
II. SCORPIONES V
The Anatomy of scorpions is unusual within the
Arachnida
 In addition to the claw-like pedipalps (similar to
those of the pseudoscorpions), five-segmented
post abdomen and stinger (telson), scorpions have
jointed claw-like chelicerae and strange wing-like
sensory organs called pectines on their underside.
 The function of the pectines is still debated, but
they seem to function in habitat scanning and
chemoreception
ORDERS OF ARACHNIDA:
II. SCORPIONES VI
Other important sense organs include:
 The eyes (both median and lateral), which
function in vision, light level perception
and entrainment of daily activity
 The trichobothria (thin hairs), which are
primarily air-borne vibration and touch
receptors
ORDERS OF ARACHNIDA:
II. SCORPIONES VII
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The reproductive biology of scorpions is
much better known than in J. Henri Fabre’s
time, when the exact mode of fertilization
in these animals was unknown
We now know that the male produces a
characteristic spermatophore and pulls the
female over this sperm package, which is
then picked up in her genital opening.
ORDERS OF ARACHNIDA:
II. SCORPIONES VIII
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A few species of Tityus from northern
South America are parthenogenic and have
few or no males
Young scorpions are produced alive by
viviparity
The young of some species are attached to
the mother at their mouth, forming a sort of
placenta
ORDERS OF ARACHNIDA:
II. SCORPIONES IX
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After being born, young scorpions climb
onto the dorsal surface of the mother,
where they remain until their first molt
The young scorpions then disperse
Scorpions may live for several years, even
after reaching adulthood
A few may live as long as 20 years
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY I
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Sissom (1990) recognized nine extant families world wide
(Bothriuridae, Buthidae, Chactidae, Chaerilidae,
Diplocentridae, Ischnuridae, Iuridae, Scorpionidae and
Vaejovidae)
Fet, et al. (2000) revised this to sixteen extant families
Soleglad & Sissom (2001) removed the family
Scorpiopidae and made it a subfamily of the Euscorpiidae
The families have been rearranged again in 2003 and
2005, by Soleglad & Fet and Soleglad, Fet & Kovarik
(strongly opposed by Prendini and Wheeler 2005)
Scorpion taxonomy is still in flux
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY II
Extant Families (According to Fet, et al., 2000)
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Bothriuridae
Buthidae
Chactidae
Chaerilidae
Diplocentridae
Euscorpiidae
Heteroscorpionidae
Ischnuridae
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Iuridae
Microcharmidae
Pseudochactidae
Scorpionidae
Scorpiopidae
Superstitionidae
Troglotayosicidae
Vaejovidae
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ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY II
Extant Families as of 2006 (according to Soleglad and Fet
2003, Soleglad, Fet and Kovarik 2005, with notes)
Bothriuridae
 Iuridae
Buthidae
 Microcharmidae
Caraboctonidae (some
 Pseudochactidae
Iuridae included)
 Scorpionidae
Chactidae (some Iuridae
(Diplocentridae included)
included)
 Superstitionidae
Chaerilidae
Euscorpiidae
 Vaejovidae
Hemiscorpiidae
(Ischnuridae included)
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY II
Extant Families as of 2006 (according to Prendini and
Wheeler 2005)
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Bothriuridae
Buthidae
Chactidae
Chaerilidae
Diplocentridae
Euscorpiidae
Hemiscorpiidae
Heteroscorpionidae
Iuridae
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
Liochelidae
Microcharmidae
Pseudochactidae
Scorpionidae
Scorpiopidae
Superstitionidae
Troglotayosicidae
Urodacidae
Vaejovidae
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY II
Families
The following arrangement is based on the
classification prior to 2003. Because of
the controversial status of scorpion
taxonomy it seems to be wise to be
conservative until a consensus is reached
on the classification.
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY III
Families

Buthidae (702 species in 80 genera)
- sternum triangular or subpentagonal (unlike any
other scorpion family except Microcharmidae)
- distribution: North America, Central America,
South America, Caribbean, Europe, Asia, Africa,
Australia, Pacific Islands
- most, if not all, known dangerously venomous
species belong to this family
- largest scorpion family
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY III
BUTHIDAE EXAMPLES (OLD WORLD)
Androctonus amoreuxi
One of the
“Fat-Tailed
Scorpions”
Very dangerous
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY III
BUTHIDAE EXAMPLES (OLD WORLD)
Leiurus quinquestriatus
The “Death Stalker”
One of the most
dangerous scorpions
known
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY III
BUTHIDAE EXAMPLES (NEW WORLD)
Centruroides vittatus
Female with young
Centruroides
gracilis Female
Photo by D. Richman
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY III
BUTHIDAE EXAMPLES (NEW WORLD)
Centruroides exilicauda Arizona -The Arizona Bark Scorpion
Dangerous
Photo copyright Jillian Cowles
Photo copyright Jillian Cowles
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY IV
Families

Microcharmidae (7 extant species in 3 genera,
separated from the Buthidae by Lourenço 1996)
- sternum triangular (as in Buthidae)
- distribution: Africa
- none are known to be dangerous
- tiny scorpions (7-16 mm total adult length)
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY V
Families

Chactidae (149 species in 12 genera)
- sternum pentagonal (like most other
scorpion families)
- distribution: North America (Mexico)
south into South America.
- none are known to be dangerous
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VI
Families

Superstitionidae (10 species in 5 genera)
- sternum pentagonal (like most other scorpion
families)
- distribution: North America (Mexico, Arizona,
California, Nevada and New Mexico).
- none are known to be dangerous
- most are found in wet subtropical caves
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VI
SUPERSTITIONIDAE EXAMPLES
Sotanochactas
Superstitionia
ellioti – MEXICO
donensis -ARIZONA
Photo Copyright Robert Mitchell
Photo copyright Jillian Cowles
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VII
Families

Vaejovidae (147 species in 10 genera)
- sternum pentagonal (like most other
scorpion families)
- distribution: North America south into
Guatemala
- none are known to be dangerous
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VII
VAEJOVIDAE EXAMPLES
Vaejovis
spinigerus SW US
Vaejovis
vorhiesi SW US
Photo by D. Richman
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VII
VAEJOVIDAE EXAMPLES
Vaejovis
carolinianus SE US
Photo Copyright W. D. Sissom
Vaejovis
coahuilae SW US
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VII
VAEJOVIDAE EXAMPLES
Vaejovis
russelli SW US
Photo Copyright W. D. Sissom
Vaejovis
crassimanus SW
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VII
VAEJOVIDAE EXAMPLES
Vaejovis intermedius
MEXICO
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VII
VAEJOVIDAE EXAMPLES
Paruroctonus
gracilor SW US
Photo Copyright W. D. Sissom
Paruroctonus
pecos SW US
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VII
VAEJOVIDAE EXAMPLES
Paruroctonus
utahensis SW US
Smeringurus
mesaensis SW US
Photo by D. Richman
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VII
VAEJOVIDAE EXAMPLES
Pseudouroctonus
apacheanus
SW US
Photo by D. Richman
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VIII
Families

Iuridae (21 or 22 species- there is some
disagreement about the monotypic genus
Anuroctonus)
- sternum pentagonal (like most other scorpion
families)
- distribution: North America, South America and
southwestern Eurasia
- none are known to be dangerous
- includes the largest scorpions in the United Statesto over 100 mm
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VIII IURIDAE
EXAMPLES
Hadruroides
maculatus S. AMER.
Photo Copyright W. D. Sissom
Hadrurus arizonensis
SW US
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY VIII
IURIDAE EXAMPLE
Anuroctonus
phaiodactylus
Male
CALIFORNIA
Photo David
Richman
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY IX
Families

Scorpionidae (105 extant species)
- sternum pentagonal (like most other
scorpion families)
- distribution: Africa, Asia and Australia
- none are known to be dangerous
- includes some of the largest scorpions- to
over 200 mm
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY IX
SCORPIONIDAE EXAMPLES
Pandinus imperator
WEST AFRICA
Photo Copyright W. D. Sissom
Heterometrus
laoticus SE ASIA
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY IX
SCORPIONIDAE EXAMPLES
Pandinus viatoris
Photo by D. Richman
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY X
Families

Hemiscorpiidae (7 extant species separated from
the Scorpionidae by Prendini 2000)
- sternum pentagonal
- distribution: Western Asia, northern Africa
- none are known to be dangerous
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY XI
Families

Urodacidae (18 extant species separated
from the Scorpionidae by Prendini 2000)
- sternum pentagonal
- distribution: Australia
- none are known to be dangerous
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY XII
Families

Ischnuridae (56 extant species in genera)
- sternum pentagonal (like most other
scorpion families)
- distribution: All continents, except North
America
- none are known to be dangerous
- includes some of the longest scorpions
(body length)- to over 200 mm
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY XII.
ISCHNURIDAE EXAMPLES
Hodogenes troglodytes
SOUTH AFRICA
Photo by D. Richman
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY XIII
Families

Diplocentridae (76 extant species)
- sternum pentagonal (like most other scorpion
families)
- distribution: North America, Central America,
South America and Caribbean
- none are known to be dangerous
- Many with tubercle below sting (as in the buthid
genera Centruroides, Tityus and Isometrus, but
stouter in diplocentruds)
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY XIII
DIPLOCENTRIDAE EXAMPLES
Diplocentrus
peloncillensis NM
Diplocentrus
spitzeri AZ
Photo by D. Richman
Photo Copyright W. D. Sissom
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY XIV
Families

Bothriuridae (125 species in 15 genera)
- sternum reduced to a transverse slitlike
sclerite or at least twice as wide as long
(unlike any other scorpion family)
- distribution: South America, Africa, India
and Australia
- no known dangerously venomous species
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY XV
Families

Chaerilidae (21 extant species in 1 genus)
- sternum pentagonal (like most other
scorpion families)
- distribution: Asia
- none are known to be dangerous
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY XVI
Families

Euscorpiidae (41 extant species, including
Scorpiopidae)
- sternum pentagonal (like most other scorpion
families)
- distribution: Mediterranean, Asia, Mexico,
Guatemala
- none are known to be dangerous
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY
XVII Families

Pseudochactidae (1 extant species,
described by Gromov 1998)
- sternum pentagonal?
- distribution: Tajikistan, Uzbekistan
- none are known to be dangerous
-no photographs
ORDERS OF ARACHNIDA:
II. SCORPIONES X- TAXONOMY
XVIII Families

Troglotayosicidae (7 extant species, separated
from the Superstitionidae by Lourenço 1998)
- sternum pentagonal (as in most scorpion
families)
- distribution: Europe (France and Spain), South
America (Ecuador)
- none are known to be dangerous
ORDERS OF ARACHNIDA:
II. SCORPIONES XI – MAJOR
REFERENCES
Dunlop, J. A. 1999. Fossil evidence,
terrestrialization and arachnid phylogeny.
Journal of Arachnology 27:86-93.
Fet, V., W. D. Sissom, G. Lowe, and M. E.
Braunwalder. 2000. Catalog of the scorpions of
the world (1758-1998). New York Entomological
Society, New York City.
Keegan, H. L. 1980. Scorpions of medical
importance. University Press of Mississippi,
Jackson.
ORDERS OF ARACHNIDA:
II. SCORPIONES XI – MAJOR
REFERENCES
Polis, G. A. (Ed.) 1990. The biology of scorpions.
Stanford University Press, Stanford, California.
Prendini, L., and W. C. Wheeler. 2005. Scorpion
higher phylogeny and classification, taxonomic
anarchy, and standards for peer review in
online publication. Cladistics 21:446-494.
Soleglad, M. E. & V. Fet. 2003. High-level
systematics and phylogeny of the extant
scorpions (Scorpiones: Orthosterni).
Euscorpius, 11, pp. 1–175.
ORDERS OF ARACHNIDA:
II. SCORPIONES XII- INTERNET
SITE


http://www.ub.ntnu.no/scorpion-files/
This site has a number of links that will
get you to just about any scorpion site in
the world
It currently uses the classification proposed
by Soleglad & Fet. 2003
ORDERS OF ARACHNIDA:
III. SCHIZOMIDA – I

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Tiny (5-7 mm) whip scorpions with a very short
flagellum (“tail”)
Median eyes lacking
Found under rocks, bricks, in deep retreats under
leaves and logs
Feed on small arthropods
Have acetic acid-producing glands like Uropygi
Male produces spermatophore
Female lays small number (less than 10) eggs
ORDERS OF ARACHNIDA:
III. SCHIZOMIDA – II - Example
Protoschizomus pachypalpus Tamaulipas, Mexico
Female on left, male on right
ORDERS OF ARACHNIDA:
IV. PALPIGRADI - I
 Minute whip scorpions (only a few mm in
length)
 Flagellum long (15 segments)
 Rare inhabitants of soil and leaf litter
 Possibly eaters of other arthropod eggs
 Only a few known species, including one
from Texas
ORDERS OF ARACHNIDA:
IV. PALPIGRADI – II- Example
Prokoenenia wheeleri Texas
Photo Copyright Lynn McCutchen
ORDERS OF ARACHNIDA:
V. Thelyphonida or Uropygi - I






Giant whip scorpions (to over 100 mm, including
flagellum)
Long flagellum
Front legs slender and long
Male produces spermatophore
Female lays up to 35 or so eggs
Newly hatched young ride on female’s back
ORDERS OF ARACHNIDA:
V. Thelyphonida or Uropygi – II- Example of
Uropygid
Mastigoproctus
giganteus
New Mexico
Photo by
D. Richman
ORDERS OF ARACHNIDA:
V. Thelyphonida or Uropygi – II- Example of
Uropygid
Mastigoproctus giganteus- Arizona
Photo copyright Jillian Cowles
Photo copyright Jillian Cowles
ORDERS OF ARACHNIDA:
VI. Amblypygi - I
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Tail-less whip scorpions or whip spiders
Medium to large, flattened, spider-like arachnids
with very long whip-like front legs
Lack flagellum (tail)
Commonly cave-dwellers, or under rock over
hangs and rock slides
Predators on other arthropods
Females produce eggs
ORDERS OF ARACHNIDA:
VI. Amblypygi – II Example
A Tropical Whip Scorpion
ORDERS OF ARACHNIDA:
VI. Amblypygi – II Example
A Whip Scorpion, Paraphrynus mexicanus - Arizona
Photo copyright Jillian Cowles
Photo copyright Jillian Cowles
ORDERS OF ARACHNIDA:
VI. Amblypygi – II Example
A Whip Scorpion
Phrynus sp.
Tamaulipas, Mexico
ORDERS OF ARACHNIDA:
VII. Solifugae - I
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Small to relative large (to 50 mm) very odd arachnids
with jaw-like chelicerae and segmented abdomens
Odd sensory structures called racquet organs or
malleoli on ventral hind legs
Widespread, especially in deserts, where they are
nocturnal predators
These are fast moving arachnids with high metabolic
rates and relatively short lives -only a few months for
adults- all appear to be univoltine
ORDERS OF ARACHNIDA:
VII. Solifugae - II
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Males pick up sperm with their chelicerae and insert them
into the female’s genital opening
Females produce up to 200 eggs
Called wind scorpions, sun spiders or camel spiders,
occasionally confused with the Child of the Earth
(actually a burrowing cricket) in the American Southwest
Camel spiders in the middle east and North Africa are
reputed to be deadly, probably as a result of people
watching them feed
Solpugids can bite, but have no venom
Bacterial infection is however, a possibility
ORDERS OF ARACHNIDA:
VII. Solifugae – III – taxonomy - * families
found in USA
Families of Solifugae
Rhagodidae
Solpugidae
Galeodidae
Ceromidae
Daesiidae
Ammotrechidae*
Mummuciidae
Hexisopodidae
Eremobatidae*
Melanoblossidae
Karschiidae
Gylippidae
ORDERS OF ARACHNIDA:
VII. Solifugae – IV Example
A Solpugid
ORDERS OF ARACHNIDA:
VII. Solifugae – IV Example
Family Eremobatidae from New Mexico
Female
Photo by D. Richman
ORDERS OF ARACHNIDA:
VII. Solifugae – IV Example
Family Eremobatidae
from Arizona
Female
Photo copyright Jillian Cowles
ORDERS OF ARACHNIDA:
VIII. Pseudoscorpiones - I
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Tiny (usually not over 5 mm), scorpion-like
arachnids without slender postabdomen ending in
stinger
Venom glands in pedipalpi
Silk glands in chelicerae
Male produces spermatophore and pulls female
over it
Females lay small number of eggs
ORDERS OF ARACHNIDA:
VIII. Pseudoscorpiones – II- Taxonomy- *
known from North America
Families of Pseudoscorpions
Tridenchthoniidae*
Chthoniidae*
Neobisiidae*
Syrinidae*
Gymnobisiidae
Syarinidae
Hyidae
Ideoroncidae*
Menthidae*
Olpiidae*
Garypidae*
Miratemnidae*
Pseudogarypidae*
Synsphyronidae
Cheiridiidae*
Feaellidae
Pseudocheiridiidae*
Sternophoridae*
Myrmochernetidae
Chernetidae*
Atemnidae*
Cheliferidae*
Withiidae*
ORDERS OF ARACHNIDA:
VIII. Pseudoscorpiones – III Example
Pseudoscorpion from Mt.
Taylor, Cibola Co., NM
Photo by D. Richman
ORDERS OF ARACHNIDA:
VIII. Pseudoscorpiones – III Example
Pseudoscorpion from
Animas Mountains,
Hidalgo Co.,
NM
Photo by D. Richman
ORDERS OF ARACHNIDA:
VIII. Pseudoscorpiones – III Example
Pseudoscorpion from
Arizona
Photo copyright Jillian Cowles
ORDERS OF ARACHNIDA:
IX. PHALANGIDA OR OPILIONES - I
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Harvestmen are predators and possibly
scavengers- none feed on plant material, as
some mites do
Common in forests and often in rural
settings, opilionids sometimes form dense
aggragations
Most have long to very long walking legs
ORDERS OF ARACHNIDA:
IX. PHALANGIDA OR OPILIONES - II
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Abdomen is composed of ten segments; only
completely visible in the “primitive sub-order
Cyphophthalmi; other two sub-orders have nine
visible
Size varies from 1-20 mm, but most 5-10 mm
Chelicerae unique in being three-segmented
Distribution: Worldwide, except polar regions
ORDERS OF ARACHNIDA:
IX. PHALANGIDA OR OPILIONES – III Taxonomy
Families of Opiliones
Sironidae*
Phalongodidae*
Cosmetidae*
Cladonychidae*
Triaenonychidae*
Travuniidae*
Oncopodidae
Assamiidae
Gonyleptidae
Pentanychidae*
Nemastomatidae*
Trogulidae*
Ceratolasmatidae*
Phalangiidae*
Gagrellidae*
Ischyropsalidae
ORDERS OF ARACHNIDA:
IX. PHALANGIDA OR OPILIONES – IV
Examples
All from southwest US
Photos D. Richman
ORDERS OF ARACHNIDA:
X. ACARI - I
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Largest order of Arachnida, with at least
50,000 species
Arachnid order with widest range of food
habits- including phytophagous, parasitic,
and predatory species
Mostly small (1 mm or less)- some to 10
mm
ORDERS OF ARACHNIDA:
X. ACARI - II
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Ticks are parasitic, as are mites in several families
Many transmit major diseases, such as Rocky Mountain
spotted fever and Lyme disease
All body segments fused into pill-like or elongated bodysome have traces of segmentation
Most lay eggs, but some produce living young
Larvae are six-legged; nymph to adult eight-legged
Complex order usually studied by specialists not
associated with other arachnologists
ORDERS OF ARACHNIDA:
X. ACARI – III Example
Ixodidae
An Ixodid tick
ORDERS OF ARACHNIDA:
X. ACARI – III Example
Desert velvet mite
Dinothrombium
New Mexico
Photo by D. Richman
ORDERS OF ARACHNIDA:
X. ACARI – III Example
Tetranychidae
Spider mites on
Webbing
New Mexico
Photo by D. Richman
ORDERS OF ARACHNIDA:
XI. RICINULEI - I
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Tick-like, small (4-10 mm) arachnids with
distinctly segmented bodies
Eyeless
Hood over chelicerae
Sluggish and slow-moving
Found in leaf litter, caves and under rubbish
Spermatophore transferred by male
Female lays eggs
ORDERS OF ARACHNIDA:
XI. RICINULEI – II Example
Cryptocellus pelaezi Tamaulipas, Mexico