The wingless bristletails, or archaeognathans, represent an ancient evolutionary stage that links the wingless and winged insects. The extinct forms are grouped with the Archaeognatha, the most basal of insect groups, and date from the Early Devonian Period. These extinct forms were small creatures, and their three-pronged tail filaments made up most of their length. Archaeognathans most likely fed on detritus such as the dead plant material that covered the floor of their ancient swamp habitats. They could jump-start their movement by flexing their abdomen and jumping. Another indication of their basal design is that they underwent minimal metamorphosis: The young were similar in appearance to the adults.
Silverfish are another wingless insect that probably arose during the Devonian, although definitive specimens do not begin to occur in the fossil record until sediments dating from the Cretaceous Period. Silverfish are classified as zygentomans. They were more flattened than bristletails and were unable to jump.
Was this article helpful?