- Schizomida
Taxobox
name = Schizomida
image_caption = Schizomid dorsal scheme
regnum =Animal ia
phylum =Arthropod a
subphylum = Chelicerata
classis =Arachnid a
ordo = Schizomida
ordo_authority = Petrunkevitch, 1945b
subdivision_ranks = Families
subdivision =Calcitronidae † Petrunkevitch, 1945bHubbardiidae Cook, 1899Protoschizomidae Rowland, 1975Schizomida is an order of
arachnid s, superficially resembling spiders and generally less than 5mm in length.The order is not yet widely studied. As of
2005 , more than 230 species of schizomids have been described worldwide, most belonging to theHubbardiidae family. Asystematic review including a full catalogue may be found in Reddell & Cokendolpher (1995).Anatomy
In schizomids, the
prosoma (cephalothorax) is covered by a large protopeltidium and smaller, paired, mesopeltidia and metapeltidia. The name means "split or cleaved middle", referring to the way the thorax is divided into two separate plates. There are no eyes.The
opisthosoma (abdomen) is a smooth oval of 12 recognizable somites. The first is reduced and forms thepedicel . The last three are much constricted, forming thepygidium . The last somite bears the whip-like tail orflagellum , which in this order is short and consists of not more than four segments.Like the related orders Uropygi,
Amblypygi , andSolifugae , the schizomids use only six legs for walking, having modified their first two legs to serve as sensory organs. They also have large well-developedpedipalp s (pincers) just behind the sensory legs.Habitat
Schizomids are generally tropical creatures, although some populations have been found in
California andArizona . They tend to live in the top layer of soil and in the cavities beneath logs and rocks, where they can avoiddesiccation . They seek water and avoid light. Some species aretroglobites (cave-dwellers), and a few live in or neartermite orant colonies.ubtaxa
Schizomids are grouped into three families:
*Calcitronidae † (fossil)
*Hubbardiidae
*Protoschizomidae References
* Reddell, J.R. & Cokendolpher, J.C. (1995). Catalogue, bibliography, and generic revision of the order Schizomida (Arachnida). Tex. Mem. Mus., Speleol. Monogr. 4: 1-170
* Savory, T., 1977. Arachnida. second edition. Academic Press inc. New York. 339pp.
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