Hello thanks for the question. And I have only heard about this through word of mouth from My Tortoise Vet, and other Tortoise Owners. My Tortoise’s Veterinarian says he sees a lot of pyramiding from owners who feed Mazuri Tortoise diet on a regular basis and especially as a only food source. In the wild, Leopard Tortoise’s roam and eat ALOT of grass. They eat so much because grass is very low in any nutritional value so they eat a lot of it. When you own a tortoise and feed it really high nutrients everyday, the shell can grow quicker than the body and that can lead to pyramiding when the body has no where else to store all those nutrients it starts storing it in the shell. Don’t get me wrong, Mazuri is very beneficial to Tortoise’s. But from what I’ve learned from the Vet over the years is it shouldn’t be the only daily food source. I hope that was helpful
That’s an old myth perpetuated by vets and “experts”. Lack of humidity is the main cause of pyramiding. Here are some good links to read-
https://www.tortoiseforum.org/threads/the-end-of-pyramiding.15137/
https://www.tortoiseforum.org/threads/what-is-and-what-causes-pyramiding.170559/