What is "petrognatha"

Petrognatha is a genus of longhorn beetle belonging to the subfamily Lamiinae, tribe Petrognathini. It is not to be confused with Perognathus, a genus of pocket mice.

Only one species, the giant African longhorn beetle, Petrognatha gigas, is described by Fabricius in 1792. It is found in Central Africa.

The larvae bore into the wood of fallen Acacia trees and the adults strongly resemble the bark. Furthermore, the antennae and legs resemble twigs when they are extended forward.