A stick insect preserved in amber

Amber envelops the remains of a stick insect that lived in the age of the dinosaurs. Credit: S. Chen et al./Proc. R. Soc. B

Evolution

Early stick insect was a master of disguise

Species preserved in amber is the first known to evolve elaborate structures to improve its look.

Stick insects had already evolved a striking resemblance to twigs by 99 million years ago.

Taiping Gao and Dong Ren at Capital Normal University in Beijing and their colleagues discovered a new species of stick insect (Elasmophasma stictum) in amber from Myanmar, which they dated to 99 million years ago. Other early stick insects identified by researchers only vaguely resembled sticks. But the new species had both a slender, elongated body and plate-like structures called lamellae — similar to those of modern stick insects — on either side that helped it to mimic twigs more successfully. This might have helped the creatures to hide from predators, the authors say.

The new specimen is the oldest known stick insect to boast such features. The find shows that stick and leaf insects evolved the trick of imitating vegetation earlier than previously thought.