The panda's "thumb"?

The giant panda's front paw has a special thumb-like finger that helps it eat it's favorite food - bamboo. The giant panda's skeleton contains an elongated wrist bone that functions a little bit like a thumb.

Five true digits aid manual dexterity.

A furrow between the two pads on the palm holds bamboo.

Thumb-like "finger" is not a finger at all, but a modified wrist bone that helps grasp thick bamboo stalks.