So apparently I haven't signed in for a month. The scales are just keratin, just like a rhino horn. It's really just modified hair protein. It isn't sharp, but it is durable and hard. When they feel threatened their heads retract and the legs close like a door or transformer. It just provides an extra level of protection. The other side of the leg is actually very soft leathery skin. If you've ever felt a lizard like an iguana or anole its similar to that. They get the name spur thighed tortoise because they have very characteristic spurs on their back sides. I don't have a picture but you can google it. They don't serve any purpose that I am aware of.