Aside from making it hard for surgeons to operate, the rib cage is essential. It’s a calcium battery, frame for our muscles and protects our organs and bone marrow. Ribs by themselves (like in snakes) sacrifice durability for flexibility. A broken rib endangers vital organs, a bit counterproductive considering their purpose.
The creature I have in mind is one with a rib cage made of separate bones (ribs) that are crossed together like hands, allowing them to be opened and closed similar to a bivalve. Fully opened their ribs would look like hair clippers. This would expose the organs, leaving only skin as protection but for the sake of the question we’ll assume that the organs are somewhere else or protected by another bone layer. The overall morphology of the creature is dog-like and it functions as an obligate carnivore in my sci-fi setting. It’s not a mutant or anything it just adapted or mutated to be this way. But why? I’m rather uncertain about the feature so I’m looking for a plausible explanation for it.
What would these ribs be used for? (Besides making a veterinarians job easier.)