Phasmid
Insect
Early Eocene
Green River Formation
Rio Blanco, Colorado, USA.

Arthropod. Insect. Orthopteran.

Walking sticks (phasmids) or stick insects are insects that date back at least to the Late Jurassic. They belong to the Order Orthoptera – relatives of grasshoppers, katydids, and crickets. Fossils are rare but they occur in the Green River Formation (as seen here) and nymphs have been collected in Baltic, Mexican, and Dominican ambers. They have become excellent mimics of twigs and sticks even swaying when a breeze comes through.

Today, walking sticks live in tropical and temperate regions of the continents. They must have spread out across the world as the continents separated and drifted apart during the Mesozoic and Cenozoic. 

This specimen shows that walking sticks and their relatives were already masters of camouflage by the Early Eocene over 50 million years ago.