opposable

Updated: July 28, 2025

When we look at the feet of monkeys we find a still greater difference, for these have much larger and more opposable thumbs, and are therefore more like our hands; and this is the case with all monkeys, so that even those which have no thumbs on their hands, or have them small and weak and parallel to the fingers, have always large and well-formed thumbs on their feet.

Various - Scientific American Supplement, No. 344, August 5, 1882