Previously it was thought that the first insects to help with plant fertilisation were the bees, which evolved with flowering plants during the Cretaceous Period about 100 million years ago (mya), but recent research at Portland State University has shown that mosses, which first appeared about 450 mya, emit scents which attract springtails (small arthropods which appeared at least 400 mya).
Before this study, moss reproduction was primarily thought to depend on individual sperm swimming through a water layer between male and female plants. Now it is known that springtails can transfer the sperm and increase fertilisation rates substantially.