Ephemeroptera

From EvoWiki

Ephemeroptera, mayflies. Extremely ancient insects dating to the Carboniferous, mayflies are renowned for the short duration during which the imago lives and reproduces. There are approximately 2,100 species of mayflies, distributed globally, and as a group they can be distinguished by the triangular forewings marked with numerous exaggerated crossveins. There are two to three distal, elongate filaments at the end of the abdomen which often far exceed the length of the body.

JGK