A study of three ancient fossils found on the Isle of Wight in the 1920s has revealed that evolution has not altered the fig wasp in 34 million years.
The specimens, housed at London's Natural History Museum, were previously thought to be of ants but a new examination confirmed their origins.
Dr Steve Compton, of the University of Leeds, said the fig wasp fossils were "fascinating" because of their age.
He also highlighted their similarity to the modern species.
Dr Compton, who led the study, explained: "This means that the complex relationship that exists today between the fig wasps and their host trees developed more than 34 million years ago and has remained unchanged since then."
Fig wasps attach themselves to an individual tree and spread its pollen.
Each tree is exclusively pollinated by just one or two species of wasp.
Modern fig wasps carry the pollen they collect in special pockets beneath their bodies.
Dr Compton's team was able to identify pollen pockets on the wasp fossils, and even grains of fig pollen within them.
He said: "Although we often think of the world as constantly changing, what this fossil gives us is an example of something remaining unchanged for tens of millions of years - something which in biology we call stasis."
The research has been published in the Royal Society journal Biology Letters.