Characteristics of Reptiles

Characteristics of Reptiles Class Reptilia includes snakes, lizards, crocodiles, alligators and extinct dinosaurs. The majority of reptiles are terrestrial and are adapted to a wide range of habitats. Alligators have a wide U-shaped, rounded snout like a shovel, crocodiles have V-shape. Teeth are wider in alligators and overlap lower jaw Crocodile or alligator? Gila monster Heloderma suspectum

Characteristics of Reptiles Evolved from amphibians about 350 million years ago and dominated the Earth between 245 million and 65 million years ago—the Age of Reptiles (Mesozoic era).

Characteristics of Reptiles Adaptations to terrestrial life include their dry, scaly skin (resistant to water loss and wear and tear) and their amniotic egg (consists of a hard shell and multicellular membranes, which encase the embryo in a secure, self0contained aquatic environment).

Characteristics of Reptiles Are ectothermic. Regulate their body temperature by controlling how much heat they absorb. Use lungs for respiration and have a circulatory system composed of two loops and a 3-chambered heart, in which one chamber is partially divided.

Characteristics of Reptiles More advanced nervous system than amphibians. Most have a highly-developed sense of smell. Are equipped with a specialized organ sensitive to low concentrations of odors called the Jacobsen’s organ, located in the roof of the mouth.

Characteristics of Reptiles Excrete nitrogenous wastes in the form of uric acid. In the body, uric acid is much less toxic than ammonia or urea. Thus, it requires little water for dilution, and reptiles lose only small amounts of water in their urine.

Characteristics of Reptiles More than 5,000 species of modern reptiles divided into 4 orders: Order Testudines: turtles, tortoises, and terrapins. Box turtle is land dweller along with larger galapagos tortoise and terrapin are semi-aqautic in nature and medium sized Box Turtle: Geochelone nigra vicina Galapagos tortoise Diamondback Terrapin Malaclemys terrapin Terrapene ornata

Orders of Reptiles Order Squamata: lizards and snakes. Anole: Anolis carolinensis Corn snake: Elaphe guttata

Orders of Reptiles Order Crocodilia: crocodiles and alligators. Siamese crocodile Crocodylus siamensis American Alligator Alligator mississippiensis

Orders of Reptiles Order Rhyncocephalia: tuataras Sphenodon punctatus Coast of New Zealand about 40 cm or 15 inches Sphenodon punctatus

Stores nitrogenous wastes produced by embryo Surrounds all membranes and cushions developing embryo Thin membrane enclosing the fluid in which embryo floats Encloses the yolk A fat-rich food supply Provides protection from damage and evaporation of water from egg Contains proteins and water needed by embryo