Interacting Gears Synchronize Propulsive Leg Movements

发布日期：2013-11-08 21:53 来源：网络作者：网络浏览次数：

Science 13 September 2013:
Vol. 341 no. 6151 pp. 1254-1256
DOI: 10.1126/science.1240284

Gears are found rarely in animals and have never been reported to intermesh and rotate functionally like mechanical gears. We now demonstrate functional gears in the ballistic jumping movements of the flightless planthopper insect Issus. The nymphs, but not adults, have a row of cuticular gear (cog) teeth around the curved medial surfaces of their two hindleg trochantera. The gear teeth on one trochanter engaged with and sequentially moved past those on the other trochanter during the preparatory cocking and the propulsive phases of jumping. Close registration between the gears ensured that both hindlegs moved at the same angular velocities to propel the body without yaw rotation. At the final molt to adulthood, this synchronization mechanism is jettisoned.