I thought that Pyramiding was a general doming of the carapace, almost like a bubble was caught inside the shell and was gradually making it taller and more convex. I also was under the impression that pyramiding was caused by a diet severely lacking in nutrients and just abhorrently poor in general (something like using white bread, dog food, meat, or some other heinous "food").
(NOTE: For the purposes of this post I will explain Pyramiding as it pertains to Greek Tortoises. As pyramiding affects different chelonians differently, all of the information I present will not be universally applicable. However, regardless of the turtle, tortoise or terrapin in question, a keeper must supply the diet, UV exposure, humidity level, and other key elements that mimic as closely as possible the natural habit from whence the chelonian originated in order to maintain good shell, bone, and general health. An individual who is unable or unwilling to commit to this is also unfit to share a home with these beautiful creatures and another pet should be found--perhaps a goldfish...or a plant.)
Pyramiding is a malady that manifests itself in individual scutes rather than in the carapace as a whole as I previously supposed. This is because Pyramiding is simply excessive growth and shells grow by adding keratin to the scutes. So the scutes grow too fast and start forming a piled or "pyramid-like" shape instead of a smooth surface that healthy shells should have. ("Pyramiding" is a somewhat general term that covers most shell deformities, so it is possible that other types of Pyramiding look different than this.)
In the last paragraph I used the phrase "...Pyramiding is simply..." which is actually an oxymoron. This condition is not completely understood, so you, my readers, should remember that I am not a herpetologist and that the explanation that I give herein of Pyramiding is fairly watered-down. I do this for two reasons: First, I don't have the knowledge to delve into this topic more deeply. Second, the purpose of these articles that I write is to establish a basic understanding of complex topics and then to direct the curious/serious keeper to scholarly sources.
One such source is the World Chelonian Trust. It has two excellent articles, one on deformities/pyramiding in general and the other on the causes of pyramiding. These articles supply experiential scientifically collected information and pictures on this all-too-common ailment. I highly suggest reading these and other articles found through Googleing "tortoise pyramiding". However, in using such a broad search tool you are very likely to run into very non-scientific sources that claim to be scientific (whereas The Greek Tortoise Guild, while non-scientific, only claims to be a collection of information that leads readers to scientific sources).
I recently read an answer posted on one of those sites that let the general public respond to an individual's question. The author of the comment stated his view in a very factual manner and then stated (I must admit that this is a paraphrase), "I've had turtles for years, so I KNOW WHAT I'M TALKING ABOUT!" I decided to do my own research on the topic and found numerous credible sources, and several scientifically researched and authored sources that stated the exact opposite of what this man claimed, and then they went on to substantiate their claims with evidence (and now I'm writing a blog post about that same topic today). So, just because someone claims to know everything about Greek Tortoises from head to tail and carapace to plastron, do your own research by checking scholarly sources and talking to a veterinarian that specializes in or is at least familiar with tortoises. You will notice that I did not mention talking with pet stores. Unfortunately, some of my worst experiences with poor tortoise-care has happened in pet stores. On the other hand, if it weren't for pet stores and breeders, no one outside of the Mediterranean, Northern Africa, Eastern Europe or the Middle East would ever enjoy the beauty of the Greek Tortoise. We owe them a great debt. I am merely trying to emphasize how important it is to make sure that we all get our facts straight concerning Greek Tortoise husbandry.
Hector and Phoebe were purchased from a pet store in another state. I saw pictures of them online and spoke several times with the store owner who was actually the most knowledgeable person I had yet spoken with about Greek Tortoises. He knew the scientific name of the specific Greek Tortoises that we were discussing (Testudo graeca ibera), what country their lineage came from and even the specific region of that country (which I checked-out and indeed Greek Tortoises are found there, so I know he wasn't just making it up), how to correctly temperature-sex tortoises, he knew the breeder personally and knew him to be competent, etc. I was impressed. Surely I would be getting healthy Greek Tortoises from an establishment that knows how to care for them...
These silhouettes do well at emphasizing Phoebe's Pyramided scutes. Hector's are the same.
We have had Phoebe and Hector for about six months--not enough time to do this kind of damage. Even when we first got them we noticed that their scutes were raised much more than our past Greek Tortoises, but we attributed it to a difference in the environments from whence their subspecies originated.
Since we began learning more about Pyramiding and realized that our Hector and Phoebe had fallen victim, we researched their diet more thoroughly and made adjustments as appropriate. Hopefully, their condition will not worsen, though their shells will never be as smooth as Delilah's was:
The contrast is startling, isn't it?