Ray skeletons, like sharks, are made out of cartilage and are very difficult to preserve. Luckily, like sharks, rays also have a conveyor-like system for their dental plates, and replace them often throughout their lifetimes. K-12 teachers @maggie-paxson, @catherine-mueller, and Brett Stubbs discovered 2 different ray plates while at Montbrook. These fossils may be small, but are designed to crush mollusk shells! Once a shell is held between two plates, the rough surface of the teeth keeps the shell from slipping out, allowing the muscular jaws of the ray to grind down on the unfortunate mollusk, breaking it open.