A 50 million year old mushroom has been found trapped in amber, the first ever discovered.

The Eocene fungus was captured in time alongside the exoskeleton of a small insect, and the hair of a rodent.

Scientists say that the little tableaux gives an fascinating insight into life shortly after the dinosaurs became extinct.

The insect, which is thought to have been feeding on the mushroom seconds before, literally, jumped out of its skin after being surrounded by the sticky tree sap, and fled the scene leaving only its outer shell behind.

A rodent hair, also trapped in the amber, suggests that a mice or rat was nibbling at the mushroom before it was trapped in amber.

“From what we can see in this fossil, a tiny mushroom was bitten off, probably by a rodent, at the base of a tree,” said George Poinar, Jr, a researcher in in the College of Science at Oregon State University.

“An insect, similar to a walking stick, was probably also trying to feed on the mushroom.

"It appears to have immediately jumped out of its skin and escaped, just as tree sap flowed over the remaining exoskeleton and a hair left behind by the fleeing rodent.”