Animals with back bones Vertebrates

Fishes

Three Classes or Groups Agnatha- Lampreys and Hagfishes Chondrichthyes- Sharks and rays, Chimera Osteichthyes- Bony Fishes

Fishes Characteristics Gills for oxygen exchange Sexual Reproduction with external fertilization Two Chambered hearts Agnatha and Chondricthyes have cartilage skeletons Scales Bony fish contain a swim bladder

Semi-terrestrial animals Means double life Amphibians

Three Classes or Groups Urodela- Salamanders and newts Anura- Frogs and toads Apoda- The legless caecilians

Amphibians Characteristics Undergo Metamorphosis Tadpole to frog or Toad Salamander lose gills in the adult Ectotherm Three Chamber Heart Need Skin Wet to Breathe

Reptiles

Characteristics Scaly Skin- Prevent Water Loss Most with 3 chamber heart/ Some have 4 chambers like the crocodilians Skeletal Changes Amniotic Egg- provides nutrients and membrane to protect it from terrestrial environment Ectotherm

Reptiles Main Groups Squamata- Snakes and Lizards Chelonia- Turtles and Tortoises Crocodilia- Alligators and Crocodiles Tuatara

Birds

Characteristics Feathers- Modified scales for insulation and flight Sternum- breast bone for flight muscle attachment Endotherms Four Chamber Heart

Mammals

Characteristics Have Hair Endotherms Glands- secrete various substances needed by the animal ( saliva, milk, hormones) Diaphragm- sheet of muscles that allow for the chest cavity to expand and contract

Characteristics Adaptations for obtaining food Mammal limbs Consuming Food Teeth, Cud Chewing, Multiple stomachs Mammary Glands to Nurse Young Intelligent

Mammals Types of Mammals 1. Placental Mammals Young Develop in the Uterus Ex. Humans, Whales 2. Marsupials Young Develop in a Pouch Ex. Kangaroos, Koala Bears 3. Monotremes Young Develop in Eggs Ex. Platypus, Spiny Ant Eater