1. Phylum Chordata

2. Characteristics of Chordates ► Notochord ► Dorsal nerve cord ► Pharyngeal pouches or gill slits ► Postanal tail

3. ► Subphylum Cephalocharodata- This subphylum is composed of about 2 dozen blade-shaped animals known as lancelets. They retain all characteristic throughout life. ► Subphylum Urochordata- This subphylum is commonly known as tunicates ( sea squirts). Larva posses all chordate characteristics while adults exhibit only Pharyngeal pouches.

4. Subphylum Vertebrata ► All characteristics of chordates ► Distinguishing characteristics  Vertebral column or spine  Cranium or skull that protects the brain  Endoskeleton composed of bone or cartilage

5. Major groups of Vertebrates

6. Lampreys and Hagfishes ► Long, eel-like bodies ► Lack jaws ► Paired fins ► bones

7. Sharks, Skates and Rays ► Class Chondrichthyes  Jaws  Paired fins  Skeleton of cartilage

8. Boney Fishes ► Class Osteichthyes  Jaws  Most have a skeleton composed of bone

9. Amphibians ► Class Amphibia  Included frogs, toads and salamanders  Skin is moist and permeable to gases and water  Most lay eggs in water  Most have an aquatic larval stage

10. Reptiles ► Class Reptilia  Turtles, crocodiles, alligators, lizards and snakes  Skin is dry and scaly  Eggs that can be laid on land

11. Birds ► Class Aves  Adapted for flight ► Feathers ► Hollow bones ► Unique respiratory system

12. Mammals ► Characteristics  Endothermy  Hair  Completely divided four chamber heart  Milk produced from mammary gland  Single jawbone  Specialized teeth

13. Order Monotremata ► Egg-laying mammals ► Most primitive of mammals ► Only three species  Two anteaters and one platypus

14. Order Marsupialia ► 250 species ► The U.S. has only one species – the Virginia opossum ► Young develop in a pouch

15. Placental Mammals ► Diverse group composed of at least 18 orders ► 95% of mammals are placental ► They live on land, in water and the air