Earliest insect

The earliest species of insect is Rhyniognatha hirsti, known from the Rhynie chert rock deposits exposed at the village of Rhynie in Aberdeenshire in Scotland, UK, and dating back approximately 410 million years to the early Devonian Period. It first became known to science via a fossil head section discovered in 1919 by the Reverend W. Cran and initially deemed to be conspecific with another fossil arthropod found there at the same time, Rhyniella praecursor, the earliest known springtail. However, subsequent examination of its fossil by entomologist Robin J. Tillyard revealed that it constituted the head of a true insect, not a springtail like the other Rhynie chert remains found with it, so its now-differentiated, reclassified species was formally dubbed Rhyniognatha hirsti.

Based upon the specific shape of its jaws (mandibles), which compares closely with those of winged insects, entomologists consider that this earliest of insects may itself have been winged, which if so shows that the winged state had arisen in insects at a much earlier stage during their evolution than hitherto assumed.

Its type (and currently only known) specimen is held at London's Natural History Museum, where it is displayed on a microscope slide.