BI 173 - Chapter 29 - Reptiles.

Amphibian ancestors?

Different groups may have different derivations.

Characteristics:

    Bony skeleton w/ ribs forming thoracic basket.

    Lungs more efficient (no gills).

    Jaws more efficient.

    Dry scaly skin, w/ epidermal scales.

        Often require shedding for growth.

        May form hard plates.

        Few glands.

    3-Chambered Heart. More separation of blood flow.

        In some, ridges become legitimate septum.

    More advanced CNS - 1st real Cerebral Cortex.

    More advanced kidneys w/ uric acid produced.

    Dioecious, w/ internal fertilization, copulatory organs.

        Waterproof, leathery, sometimes calcified eggs.

            Amniote structures w/ other associated membranes.

            Large yolk.

            Young are similar to adults.

Groups:

    Turtles. Water vs Land Forms.

    Lizards & Snakes.

        Lizards - eyelids & ear openings.

        Jaw adaptations.

        Tongue sensing. Forking use.

        Heat sensing - focussed pits.

        Poisons.

    Crocodiles & Alligators.

    Dinosaurs, other extinct groups.

Michael McDarby,
        Based Upon Hickman-Roberts-Larson Biology of Animals,
            1998, WCB McGraw-Hill.
        Internet Version Uploaded 2001.