1. Vertebrates

2. Non-Vertebrate Chordates
Phylum Chordata
Notochord
Flexible, rod like structure that extends the length of the body
Non-Vertebrate Chordates
Sea Squirt Tunicate
Bluebell Tunicate
Brachiostoma Lancelot

3. SUBPHYLUM VERTEBRATA
Notochord is replaced by the vertebral column

4. The majority of fish reproduce through external fertilization in a process called spawning.
External fertilization must occur in water so the sperm can swim to the egg

5. FISH Jawless Fish No true teeth or jaws
Skeletons made of fibers and cartilage
Lack vertebrae
Two classes: lamprey and hagfishes

6. FISH Cartilaginous Fish Skeletons built of cartilage, not bone
Rays
Sharks
Cartilaginous Fish
Skeletons built of cartilage, not bone
Evolution of jaws and paired fins
Tooth-like scales covering skin, make their skin very rough (sandpaper)

7. FISH Bony Fish Tetrapod- now extinct, four footed animal
Evolved skeletons made of bone
Tetrapod- now extinct, four footed animal
Salmon

8. Costa Rica Poison Dart Frog
AMPHIBIANS
Life in wet places, ectothermic, smooth moist skin, lay eggs (in water)
Most begin their life as aquatic organisms
Ex. Frogs, toads, and salamanders
Spotted Salamander
Costa Rica Poison Dart Frog

9. Ectotherm- animals that obtain body heat from the environment

10. Why does reproduction still depend on water?
Because eggs do not have shells to keep them from drying out.

11. REPTILES
Fully terrestrial life (some live in water), scale covered skin, ectothermic, internal fertilization
Ex. Lizards, snake, turtle
Extinct- Dinosaurs

12. REPTILES Amniotic Egg- Covered with a protective shell
Has several internal membranes with fluid
Benefit: Animals do NOT have to return to the water to reproduce
Evolved Advantage:
Embryo surrounded by own watery environment

13. BIRDS Bones are lightweight, solid, and flexible allowing for flight
ENDOTHERM: An organism that generates its body heat internally by its own metabolism
Probably evolved from reptiles (dinosaurs) because:
Eggs are also amniotic
Scales on legs & feet
Bones are lightweight, solid, and flexible allowing for flight

14. MAMMALS
All mammals have hair, are endothermic, and produce milk in mammary glands

15. MAMMALS Monotremes - egg laying mammals
Marsupials - bear young early and keep in a pouch
Placentals - groups of mammals named for the organ that connects the mother with her developing embryo so that nutrients, oxygen, and wastes can be exchanged
Spiny Anteater
Duckbill Platypus