Scientists have discovered what they believe is the first example of interacting gears in young planthopper insects, Issus coleoptratus. The gears are on the upper portion of the insect’s rear legs and help ensure the legs work in unison when the insect jumps. These gears are lost as the animal ages and are thus rather like training gears.
Dr. Malcom Burrows (Emeritus Professor of Neurobiology at the University of Cambridge, UK) was quoted in Live Science as saying “To the best of my knowledge, it’s the first demonstration of functioning gears in any animal.”
Here is a video of the gears in action:
Burrows M, Sutton G. Interacting gears synchronize propulsive leg movements in a jumping insect. Science. 341(6151):1254-1256, 2013.