Tortoiseshell Tortoiseshell Tortoiseshell or tortoise shell is a material produced from the shells of the larger species of tortoise and turtle, mainly the hawksbill sea turtle, which is an endangered species largely because of its exploitation for the material. The large size, fine colour and unusual form of the hawksbill's scutes make it especially suitable. The distinctive patterning is referred to in names such as the tortoiseshell cat, several breeds of guinea pig, and the common names of several species of the butterfly genera "Nymphalis" and "Aglais", and some other uses. Tortoiseshell was widely used from ancient times in the West
Turtle shell of the turtle's shell is unique because of how the carapace represents transformed vertebrae and ribs. While other tetrapods have their scapula, or shoulder blades, found outside of the ribcage, the scapula for turtles is found inside the ribcage. The shells of other tetrapods, such as armadillos, are not linked directly to the vertebral column or rib cage allowing the ribs to move freely with the surrounding intercostal muscle. However, analysis of the transitional fossil, "Eunotosaurus africanus" shows that early ancestors of turtles lost that intercostal muscle usually found between the ribs. Recent breakthroughs in stem-turtle fossil records contribute to