Order Testudinata is the scientific name for the order of animals that includes all species of turtles, terrapins, and tortoises. This group is characterized by their hard, protective shell and their distinctive body plan, which includes a beak-like mouth, four sturdy legs, and a long, strong tail. While Order Testudinata is the most commonly used term for this group of animals in scientific circles, there are also many synonyms and related terms that can be used interchangeably, such as Chelonia, Testudines, and Testudinidae. These terms may be useful in different contexts, such as in taxonomy, anatomy, or ecology, and can help scientists communicate more effectively about these fascinating creatures.