Phylum Chordata - Jefferson County Public Schools

Phylum Chordata Characteristics of Chordates Notochord Notochord Dorsal nerve cord Pharyngeal pouches or gill slits Postanal tail Subphylum

Cephalocharodat a- 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. 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 Major groups of Vertebrates Lampreys and Hagfishes Long, eel-like bodies Lack jaws Paired fins

bones Sharks, Skates and Rays Class Chondrichthy es Jaws Paired fins Skeleton of cartilage

Boney Fishes Class Osteichthyes Jaws Most have a skeleton composed of bone 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

Reptiles Class Reptilia Turtles, crocodiles, alligators, lizards and snakes Skin is dry and

scaly Eggs that can be laid on land Birds Class Aves Adapted for flight Feathers

Hollow Unique bones respiratory system Mammals Characteristics Endothermy

Hair Completely divided four chamber heart Milk produced from mammary gland Single jawbone Specialized teeth Order Monotremata Egg-laying

mammals Most primitive of mammals Only three species Two anteaters and one platypus Order Marsupialia 250 species The U.S. has only one species the Virginia opossum

Young develop in a pouch Placental Mammals Diverse group composed of at least 18 orders 95% of mammals are placental They live on land, in water and the air