Structure
The archedictyon is believed to have contained between six and eight longitudinal veins, but current understanding of the design is based on a combination of fossil data and speculation.
The "Comstock-Needham system" designed by entomologists John Henry Comstock and George Needham describes these veins and their branches:
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- Costa(C): the leading edge of the wing
- Subcosta(Sc): the second longitudinal vein (behind the costa), typically unbranched
- Radius R): the third longitudinal vein, one to five branches reach the wing margin
- Media(M): the fourth longitudinal vein, one to four branches reach the wing margin
- Cubitus (Cu): fifth longitudinal vein, one to three branches reach the wing margin
- Anal veins (A1, A2, A3): the unbranched veins behind the cubitus
Crossveins are named based on their relative position to the more prominent longitudinal veins:
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- C-SC crossveins run between the costa and subcosta
- R crossveins run between adjacent branches of the radius
- R-M crossveins run between the radius and media
- M-CU crossveins run between the media and cubitus
Read more about this topic: Archedictyon
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