Malacochersus Manouria Psammobates Pyxis Stylemys (extinct) Testudo Tortoises or land turtles are land-dwelling reptiles of the family of Testudinidae , order Testudines . Like their marine cousins, the sea turtles , tortoises are shielded from predators by a shell. The top part of the shell is the carapace , the underside