https://www.wired.com/story/aye-aye-pseudothumb/

If it seems too good to be true, the old cliché goes, it probably is. And it doesn’t get much gooder than the bizarre hand of the aye-aye, a specialized lemur that uses a hyper-elongated middle finger to tap along hollow tree branches, listens for grubs within, gnaws a hole in the wood, and reaches that middle finger inside to fish out the food. It would seem, then, that the aye-aye (so named because of its cries) wanders the forests of Madagascar giving the world the highly elongated finger.

But now, a discovery that really ruins that gag: While exploring the anatomy of the aye-aye’s forearm and hand, a group of researchers discovered the critter has tiny pseudothumbs that likely help it grip branches. Technically speaking, then, the aye-aye has six digits on each hand, so it has no middle finger. Thus in one discovery, the aye-aye grows more remarkable yet less joke-worthy.