Sly's shell does not look bad. The ridge you see is normal. True pyramiding is rare in turtles, that's not saying it doesn't happen. When it does, it is usually a result of poor diet and environment. Pyramiding is much more common in tortoises. YBSs are omnivores. They should be fed mostly greens and vegetables with a small amount of protein in the form of prey such as feeder fish, crickets and earthworms. A commercial pelleted diet supplemented with greens and prey is recommended. Calcium and multivitamin supplements, usually powders sprinkled on food, are necessary. UVB lighting is also critical to shell health.