Examples of representing beings: snakes, turtles, crocodiles, lizards, dinosaurs (extinct). Basic morphology: tetrapods, some with carapaces (like turtles). Skin: impermeable keratinized, corneous plates (known as scales). Respiration: pulmonary. Circulation: closed, incomplete, heart with three chambers and partial interventricular septation. Nitrogen waste: uric acid. Thermal control: heterothermic. Types of reproduction: sexual, internal fecundation, shelled eggs with extraembryonic membranes.
