Turtles are weird. . .
Dermal bone plates form a dorsal carapace and a ventral plastron
Carapace and plastron are usually covered with keratinous epidermal scutes
Carapace typically is fused to the ribs and vertebrae
Limb girdles lie inside the ribcage
Since the ribcage cannot expand, turtles use ěpistonî movements of internal organs and pectoral girdle to fill and empty lungs