This is an Indian Star Tortoise. Two mathematicians tested 30 of them for self-rightingness, found many of the tests to be positive, and explained the small size of their sample as follows: “it’s much work, measuring turtles.”
You might not have encountered the word self-rightingness before. I certainly hadn’t, prior to making it up a minute ago. It refers to something that rights itself when knocked over, like the toy that sometimes goes by the name of the Comeback Kid.
Two mathematicians wondered if there was a shape with this property but without the Kid’s cheating weighted bottom. They found that there is, and had one made. They also found that nature had come close to the shape, in the form of our friend in the photo.
If you think that these mathematicians must be smart, remember that they seem unaware of the difference between a tortoise and a turtle. And check out what one of them did on his honeymoon, prompting his colleague to remark that: “You need a special woman for this.”