1. Chordata Classification

2. Chordates 4 characteristics: Notochord Pharyngeal slits
Dorsal, hollow nerve cord
Muscular, post-anal tail

3. Craniates Animals that have a brain case, or a skull
Skull – box of hard tissue (cartilage or bone) that encases the brain, olfactory organs, eyes, inner ear and usually jaws/teeth
Neural crest cells (collection of cells that disperse during development) become:
Parts of the cartilage/bone of the skull and jaws, as well as teeth
Inner layer of skin cells that line the face region
Sensory capsules in which sensory organs develop
Several types of neurons

4. Craniates continued… More active Have a higher metabolism
More extensive muscular system
Especially along the digestive tract
More developed circulatory system
Heart with 2 or more chambers
Red blood cells – to deliver oxygen to muscles
Hemoglobin
Kidneys – to remove wastes from the blood

5. Vertebrates Have backbones
Replaces the notochord (provides structure & flexibility)
More extensive skull and bone structure to protect the central nervous system

6. Gnathostomes “jaw-mouth” Animals with hinged jaws
For gripping, slicing, tearing , and chewing food
Also have an enlarged forebrain
To house enhanced sensory equipment (for smell and vision)

7. Osteichthyans
Animals that have a bony endoskeleton
Cartilage or bone

8. Tetrapods “4 feet” Have 4 limbs
Evolved to living and moving on the land
Fusion of pelvis and backbone and the development of bone structure for terrestrial living
Lung development for obtaining oxygen from air
Pharyngeal slits become inner ear parts (not gills)

10. Amniotes
Animals who’s young are protected within an egg surrounded by specialized membranes
Membrane functions:
Shell – protection and water retention
Membranes for nutrient transfer and gas exchange
Amnion – membrane that acts as a shock absorber