At the Giant Panda Museum in the Wolong Giant Panda Protection Area in Sichuan, we may take a closer look at the palm of giant pandas – they actually have six fingers. In addition to the thumb in the normal position, it also has another thumb.
A very small number of humans grow six fingers in their mothers’ wombs, with also two thumbs. However, the extra thumb is abnormal and redundant. In the human’s life in the future, the thumb would not be useful, and would even cause inconveniences.
On the contrary, the sixth finger of giant pandas is useful. Without this extra thumb, it’d be impossible for pandas to strive on bamboo.
From an anatomical point of view, the panda’s thumb is not an actual finger – it is completely different from the sixth finger that human beings would have. The panda’s thumb is made up of sesamoids, which are small bones that grow in the wrist.
A panda’s sesamoids grow a lot more than the other fingers, and its length is similar to the real palmar bone. This extra thumb (the sesamoid) supports the pads of the panda’s front paws, and the other five fingers form the contour of another pad, which together form the palm with which the panda can move flexibly.