Reptiles: Scaly Or Slimy

Reptiles: Scaly or Slimy? Kingdom: Animalia Phylum: Chordata Class: Reptilia

Reptiles:  have dry, thick, scaly skin. This is to prevent drying out the organism and for protection to some extent.

 legs are positioned more underneath the body for support and for running. Legs on amphibians are positioned on the side; not capable of lifting the body off the ground, nor running.

 have internal fertilization and reproduce on land.

 lay amniotic eggs that have a tough outer covering and multiple membranes within. (Benefit?)

 most have inefficient three-chambered hearts, similar to amphibians. They compensate with spongy lungs that have increased surface area to absorb more oxygen into the blood.

 crocodilians have 4-chambered hearts: two atria, two ventricles. (Benefit?)

 are ectotherms. (Benefit?)

 most are skilled predators w/ a good sense of smell, which uses their tongue and Jacobson’s organ; vipers have pits (sense warm-blooded prey). Orders of Reptiles 1. Squamata—snakes and lizards. Found everywhere except the polar regions. Lizards: Have clawed toes, external ears and moveable eyelids. Most lizards are found in hot climates only. Most lizards eat insects or other small prey. Snakes: Are adapted to sliding rapidly over a variety of terrain and into small places searching for food. Kill prey in one of three ways: Constriction (boas, pythons), Venom (rattlesnakes, cobras) or swallowing whole (most snakes like garter snakes, water snakes).

2. Crocodilia— crocodiles, alligators and relatives (only 23 species in world). Are fast runners and strong swimmers. Alligators are found in the Americas only (except one species found in eastern China). Saltwater Crocodiles (Crocodylus porosus) are the largest reptiles of all (18-20 feet long weighing 1500-2000 lbs.). Eat fish or land animals that come to the water to drink.

3. Chelonia—turtles and tortoises. Have an extension of the skeleton that makes a two part shell. Top part is the carapace, bottom is the plastron. Some eat fish, many eat plants.

4. Rhynchocephalia—tuataras. Primitive lizard-like reptile with big scales and a third “eye” on top of their head (light sensing only).