At 400 million years old, Rhyniognatha hirsti is the world's oldest known insect.
Insects probably evolved 70 million years earlier, around the time plants were colonising the land for the first time. But this fossil is our earliest evidence of arthropods on land, providing a unique insight into a time of major changes in ecological diversity and animal physiology.
The first insects probably evolved from a group of marine crustaceans. They were the first animals to develop flight, a feature that allowed them to adapt and diversify during times of global climate change. Insects are now the most species-rich group of animals on Earth.
The Rhyniognatha hirsti fossil is preserved inside a piece of Rhynie Chert, a Scottish rock formation that contains exceptionally preserved fossils. These fossils, from a site near the village of Rhynie in Aberdeenshire, have given scientists a valuable insight into the first colonisation of land.