Scorpionida

Scorpionida [‚skȯr·pē′än·əd·ə]

(vertebrate zoology)

The scorpions, an order of arachnids characterized by a shieldlike carapace covering the cephalothorax and by large pedipalps armed with chelae.

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Scorpionida 

(scorpions), an order of invertebrates of the class Arachnida. The body, which is 1–18 cm long, is divided into a prosoma and a segmented opisthosoma consisting of a broad anterior section and a long narrow posterior part. The last segment of the opisthosoma contains two poison glands that open at the end of a sharp hooklike sting (telson), which is used as a means of defense and attack. The prosoma bears three to six pairs of eyes and six pairs of extremities—small chelicerae, large chelate pedipalps, and four pairs of walking legs. The respiratory organs are book lungs, which have openings on the third to sixth segments of the opisthosoma.

Scorpions are nocturnal animals that feed on insects, spiders, and myriapods. They are viviparous; the young are carried by the mother during the first days after birth. There are about 500 species, distributed in tropical and subtropical deserts and rain forests. Twelve species are found in the USSR. Scorpion stings are very painful to man, and those of large tropical specimens may be lethal.

REFERENCES

Bialynitskii-Birulia, A. A. Skorpiony. Petrograd, 1917. (Fauna Rossii i sopredel’nykh stran... Paukoobraznye, issue 1, no. 1.)
Dogel’, V. A. Zoologiia bespozvonochnykh, 6th ed. Moscow, 1975.

A. V. IVANOV