126-Million- Year Old Stick Insect Found in China Could Mimic Leaves

Researchers have found fossils of a 126-million-year old insect that mimicked leaves of plants.

There are over 3,000 different species of stick insect in the world. These insects- including the praying mantis- have mastered the art of mimicry to evade predators. Fossils of insects are hard to come by, which is why, researchers aren't sure when stick insects evolved imitation to blend with the surrounding foliage.  

Researchers at the National Museum of Natural History in Paris and colleagues found the fossilized remains of three specimens- one female and two males- in Inner Mongolia in Jehol. The newly-found insect species is named Cretophasmomima melanogramma, according to a news release.

The present study shows that stick and leaf insects were present as early as the Cretaceous period- a time when dinosaurs roamed the earth. What's interesting is that stick insects evolved mimicry much before the appearance of flowering plants. Several researchers had assumed that these insects started mimicking after the arrival of angiosperms some 100 million years ago, National Geographic reported.

"Our grand-cousins were already fooled by grand-cousins of stick and leaf insects 126 million years ago," said Olivier Bethoux of Sorbonne University in Paris, a co-author of the study, according to National Geographic. "Our discovery demonstrates that plant mimicry by insects was achieved by various insect groups, including stick insects, before the rise of flowering plants."

The ancient insect had wings with dark parallel lines. During a resting position, the insect could curl its body to resemble a tongue-like leaf of a plant called Membranifolia admirabilis- a relative of Gingko plants.

The site from where researchers unearthed the ancient insects also had fossilized remains of M. Admirabilis, suggesting that the insects started looking like nearby leaves to evade predators.

"This is yet more tantalizing evidence of early insect-plant coevolution," said paleontologist Sam Heads of the University of Illinois at Urbana-Champaign, who wasn't part of the study, according to National Geographic.

The study is published in the journal PLOS One.