A turtle's shell is an integral, living part of its skeletal system, not just a detachable suit of armor. Key Facts About Turtle Shell Sensitivity Composition: The shell is made of approximately 60 fused bones, including the turtle’s ribs and spine. It is covered by a layer of keratin scutes, similar to human fingernails. Nerve Endings: The shell contains a network of blood vessels and nerve endings that connect directly to the central nervous system. Sensory Perception: Because of these nerves,