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 and T-shaped in cross-section. Lyson hypothesizes that this morphology in "E. africanus" suggests that turtles may have fossorial origin. The wide torso gave rise to the turtle shell but during the Permian period, the broadened ribs may have provided great stability in burrowing. The skeletal structure of "E. africanus" in comparison to the extant fossorial gopher tortoise share similar features adapted to withstand the impact and force needed in digging. For example, "E. africanus" exhibits shoulders and forelimb adapted to burrowing, showing increased muscle indicated in structures such as their tubercle on the posterior coracoid and their large and wide