also: biological gear https://www.popularmechanics.com/science/animals/a9449/the-first-gear-discovered-in-nature-15916433/ https://www.popularmechanics.com/sci

also: biological gear https://www.popularmechanics.com/science/animals/a9449/the-first-gear-discovered-in-nature-15916433/ https://www.popularmechanics.com/science/animals/a9449/the-f...