Are you serious? They really have what amounts to an exoskeleton? Or maybe it's more accurate to call it a whole-body rib cage?

Just searched and found this fun article. Not really a skeleton but a collection of really stiff hairs or feathers (loosely: the genes are the same ones responsible for "other skin appendages" in vertebrates).

It’s made of caltrops!

Hahaha a living bucky ball. I didn't know I needed to see this.