Examples: Snakes, lizards, crocodiles and turtles.
Features: Reptiles are vertebrates that have their skin covered with scales, breath through their lungs and have a three-chambered heart. They are ectothermic, meaning that their body temperature varies with that of the environment. Most are oviparous (lay eggs).
Includes: all turtles, including terrestrial, fresh water and sea turtles. These are divided into three suborders: Pleurodira (turtles with side retraction of the neck into the shell), Cryptodira (turtles with retraction of the neck into the shell so that it forms an “S” inside it) and Amphichelydia (all extinct).
Including turtles, tortoises and freshwater turtles (terrapins).
Cheloniidae e Dermochelyidae
Although 31 genera have been classified for this family, there are only 5 remaining – Caretta, Chelonia, Eretmochelys, Lepidochelys, and Natator. This family of turtles is characterized by the presence of a secondary palate, head partially retractable or not, extremeties in the form of non-retractable flippers, covered with numerous small scales, and elongated fingers tightly bound by connective tissue with one or two claws in each flipper. The shell is covered with horny scutes, varying in number from species to species.
The only representative of this family is Dermochelys coriacea. It is of difficult fossilization due to the mosaic of the bony plates of the carapace, and the thick layer of fat between the bone and the “leather” coat typical of this species. This family is characterized by an extreme reduction of the bones of the carapace and plastron, and the development of a dorsal layer consisting of a mosaic of thousands of small polygonal bones. Its carapace has no scutes (the scutes are only present during the juvenile stage), the skull does not have nasal bones, the jaw surface is covered by keratin and the skeleton is filled by fat with extensive areas of vascularized cartilage, found also in the vertebrae and in the joints of the fins. These turtles have no claws.