Turtles belong to the order Testudines and come in approximately 300 species, including sea, terrestrial, and freshwater turtles, each adapted to their environments. Their unique anatomy includes a bony shell, sturdy legs, and a retractable neck for protection, and they have varying diets based on habitat. Unfortunately, many turtle species are endangered due to habitat loss and hunting, leading to ongoing conservation efforts including habitat protection and captive breeding programs.