Collection: Spiders

Beginning with scorpions, the evolution of terrestrial arachnids has been continuing for at least 400 million years, though exactly when the first arachnids became fully terrestrial is still under debate. Arachnids underwent a rapid early radiation, and today, there are 40,700 described spider species alone within the most diverse class of terrestrial arthropods. Major advances in spider evolution include the development of spinnerets and silk secretion.