Panda and bamboo: an age-old combination

The Panda it is one of the most famous animals in the world and unfortunately is also in danger of extinction. Moreover, even one of the most curious, given his diet faithful to bamboo. It feeds only on this grass, the largest grass in the world. This is where the scientists began to investigate why. Has he eaten anything else before? When did you start eating bamboo? And why exactly this vegetable? Has the panda undergone any changes since eating just bamboo?

As often happens, you have to dig into the past. Xiaoming Wang, a curator at the Natural History Museum of Los Angeles County, did. He found the fossil of an ancient panda that has an essential quirk to the animal’s diet: the false thumb. In reality it is not a thumb, but a modified wrist bone. It has an elongated shape that makes it resemble a long thumb. It is important for pandas because they can break bamboo sticks into small pieces that can be easily swallowed.

The fossil examined by the study is of an extinct species, ailur arctos. It may be the first species to develop the false thumb. It dates back to 6 million years ago in southern China. There are differences, the false thumb of the old specimen is longer than that of the current pandas. Strange, since the longer the structure, the more useful and stronger it is at breaking bamboo.

According to Wang, there is a likely answer. The first pandas to discover the false thumb eventually gave up on a traditional, omnivorous diet, as bamboo was easier to find in abundance. Also because other animals were hardly attracted to it. Too long a thumb can cause problems, so the later varieties shortened the right limb to gain efficiency and ergonomics.