1. Evolution of Tetrapods
The move onto land
365 mya

2. Lobe-fin Fishes Ancestor
Lead to 3 groups of lobe-finned fish
1) Lungfish
2) Latimeria
( a deep ocean fish once thought extinct)
3) tetrapod ancestor

6. Icthyostega : Tetrapod common ancestor
2 Extant Branches
Amphibians
Amniotes

7. Class Amphibia Reproduce in water Eggs with no shell Larvae fish-like
gills
2 chamber heart
Adults tetrapod-like
lungs
3 chamber heart

8. 3 Orders of Amphibians 1) Salamanders & newts 2) Frogs & Toads
3) Cecilians

9. Amniotes Embryos protected by membrane called amnion.
The amnion holds liquid around the embryo
Amnionic fluid
Reptiles were the first
Amniotes.
Amniote eggs let
reptiles move farther from water.

10. Evolutionary Advantage of the Move to land
Few predators
lots of food and space

11. Adaptations needed for land:
1) Lungs
a) amphibians also get O2 through skin
b) had to lose scales
c) only damp skin can take up O2

12. 2) Legs A) bonds connect to spine B) lift body C) same bones
In all vertebrates

13. 3) Improved circulatory system
Larval amphibians
& fish (1 loop)
Adult amphibians & tetrapods. (2 loops)

14. Adaptations to move to inland (far from water)
Amnion to keep embryo from drying out
Waterproof skin to keep YOU from drying out
Reptiles developed scales for waterproofing
Waterproof is air proof too so needed better lungs (more folding = more surface area)

17. Class Reptilia 1) scales 2) improved lung
3) 3 chambered heart (some 4)
4) amniote eggs

18. Orders of Extant Reptile
1) turtles & tortoises
2) snakes and lizards
3) tuatara
4) crocodilians

19. Some reptiles became dionsaurs then Some dinosaurs became birds

20. Class Aves (birds) Amniote egg Feathers (modified scales)
Wings & flight
Warm blooded
4 chamber heart
Most advanced lung

22. Class Mammalia Hair Mammary glands (milk) Amnion Warm blooded
4 chamber heart
2nd best lung w/ alveoli
Came from a primitive reptile ancestor