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Dragonflies - living fossils

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This website is one of two final projects for my college biology class. If you are searching for information about dragonflies, you will find quite alot in this web site, and also at the sources I used.

gray_petaltail001randyemmit.jpg
Tachopteryx thoreyi

Kingdom - Animalia

   Phylum - Arthropoda

       Class - Insecta

           Order – Odonata

               Suborder – Anisoptera

                   Family – Petaluridae

                      Genus - Tachopteryx

                          Species - Tachopteryx thoreyi

Highlights

     The dragonfly has bulbous eyes, six legs, a very long slender segmented body and large elongated wings. There are about 3,000 species. Their colors vary greatly, from dull gray to vivid reds and greens and blues. Size can range from less than an inch long to 3 inches long. Dragonflies belong to the order Odonata (“toothed ones”). (Waggoner &  Sabet-Peyman , 2000) Odonates are found all over temperate areas of the world, in all different types of habitats. They must have access to clean water, as the eggs are laid in or near water, and the nymphs live in water or wet soil. The grey petaltail dragonfly is the only species in the genus Tachopteryx. It belongs to the family Petaluridae. The order Odonata includes suborders zygoptera (damselflies), anisozygoptera and anisoptera. Many people call all Odonata dragonflies, however, only anisoptera are actually dragonflies.  Anisoptera wings are perpendicular to the body, while Zygoptera wings are held parallel. Anisozygoptera only have a few living species. The grey petaltail, or tachopteryx thoreyi is considered to be phylogenetically primitive (Bright & O'Brien, 1999), which means structurally, it has changed very little from its prehistoric ancestors. The Petaluridae family was one of the larger families during the Mesozoic era. Today there are only 9 Petaluridae species in the world. The tachopteryx thoreyi is one of two species of the family Petaluridae, or Petaltails, that live in North America. They are the largest mostly grey dragonfly in the Eastern United States. (Dunkle, 2000, p.31) John C. Abbott, Ph.D., entomologist at the University of Texas describes t. thoreyi’s size as: overall length: 71-82 mm; abdomen: 50-61 mm; hind wing: 45-56 mm. (Abbott, 1999) It is one of few species that have a habit of perching on tree trunks. Dragonflies do not bite or sting humans. However, females of some species have sharp blades in their ovipositors, which aide in depositing eggs. If a female with blades lands on a human mistaking a leg for a tree trunk, it may stab the leg with its ovipositor, while trying to lay eggs. Dragonflies are credited with keeping numbers of mosquitos low. Presence of dragonflies is a good indicator of a healthy ecosystem.

  

Bulleted Summary
     *One of the first insects to evolve flight was the dragonfly.
   *The oldest fossils found of the order Odonata are those of Protodonata, which are 325 million years old (Pennsylvanian Period).
   *Tachopteryx Thoreyi has changed very little from its prehistoric ancestors.
   *T. thoreyi are one of two species in the fammily Petaluridae.
   *T.thoreyi live in the Eastern United States, in desciduos forests.
     *They require clean seeps.
     *T. thoreyi are carnivorous, and capture large sized prey.
     *They are on the special concern list in New York State, as well as several other states.

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