Microcoryphia (=Archaeognatha) - The Jumping Bristletails
The jumping bristletails can be found, by day, hiding in rock crevices or under bark. They emerge at night to feed on algae, lichens and vegetable matter, both alive and dead. Primitive insects, perhaps dating back as far as the Devonian period (390 million years ago), they are a little more advanced than the Thysanurans yet still retain some very primitive features. They have compound eyes that are enlarged and medially contiguous (these strange-looking eyes glow at night when illuminated). Their abdominal segments bear styles, which are small appendages that may be remnants of ancestral limbs. Their thorax is arched and they have the ability to jump through the rapid downward flexing of the abdomen. Even the name Archeognatha is derived from Greek words referencing the creature's primitive design: "archeo" -ancient, and "gnatha"-jaw. It refers to the manner in which the mandibles connect with the head capsule, restricting them to articulating at only one point (the current ordinal name "Microcoryphia" means "small head"). Jumping bristletail eggs are scattered about singly (often disguised with bits of plants or soil) or laid in small groups of up to 30 eggs. Copulation consists of males producing a spermatophore, which they give to a female after sometimes-elaborate courtship rites. Jumping bristletails occur all over the world in a variety of habitats, from high on mountains to just above the high tide line in coastal areas. There are only about 250 species known.