1. Chordates Dr. Margaret Diamond
The Animal Kingdom
Chordates
Dr. Margaret Diamond

2. Chordates Subphyla Urochordata – tunicates (invertebrate)
Cephalochordata – lancelets (invertebrate)
Vertebrata – jawless fish, cartilagenous fish, bony fish, amphibians, reptiles, birds, mammals

3. Chordate characteristics
At some stage all have:
Notochord
Provides support
Dorsal hollow nerve cord
Spinal cord
Fluid filled
Pharyngeal gill slits or pouches
Develop into gills or other body parts
Post-anal tail

4. Chordate characteristics

5. Invertebrate Chordates
Urochordata – tunicates
Cephalochordata – lancelets
Have all chordate characteristics BUT no vertebrae

6. Vertebrate Classes

7. Agnatha – Jawless Fish Lampreys and hagfish
Have been around for 500 my
Eel-like
Smooth, slimy skin
Round, jawless mouth
Cartilagenous skeleton – no backbone
May be parasitic
Ectotherm (cold-blooded)

8. Cartilagenous Fish Chondrichthyes Sharks, rays and skates
Skeleton of cartilage
Lateral line system
Senses changes in water pressure
Excellent sight and smell
Placoid (tooth-like) scales with denticles
Oil in liver helps them to float – sink if stop swimming
Gills – some must swim to breathe
Ectotherm

9. Bony Fish Osteichthyes Tuna, goldfish, Nemo, etc. – 95% of all fish
Bony skeleton
Bony scales
Swim bladder for buoyancy; can float in one place without swimming
Ectotherm

10. Amphibia Frogs, salamanders, newts First vertebrates on land Legs
Lungs
Eggs fertilized and laid in water
Larva = tadpole; develops in water
Skin is thin, smooth, moist
Can breathe through skin
Ectotherm

11. Reptilia Lizards, snakes, turtles, dinosaurs, crocodiles
First vertebrates to live completely on land – adaptations
Thick, dry skin
Amniote egg with leathery shell; laid on land
Internal egg fertilization
Stronger legs
Ectotherm

12. Birds Aves Amniote egg with hard shell Internal fertilization
Endotherm = warm-blooded
Feathers
Light-weight bones
No teeth – crop and gizzard
Crop stores food
Gizzard has stones to grind food
Air sacs – increase oxygen intake
Legs and feet covered with thick, dry scales
Endotherms (warm-blooded)

13. Mammalia Mammals Endotherms Internal fertilization
Most give birth to live young (not eggs)
Mammary glands (nurse young)
Hair
Teeth
Lungs with diaphragm (helps with breathing – pulls air in and pushes it out)
Larger brain