1. Paleozoic Era 540,000,000 yrs ago to 250,000,000 yrs ago
Life starts in the seas and moves onto land
Six periods:
Cambrian
Ordovician
Silurian
Devonian
Carboniferous
Permian

2. Paleozoic Era Cambrian Period (540-490 MYA)
Cambrian Explosion – Most major animal phyla are found in the fossil record (mostly aquatic invertebrates with exoskeletons).
Burgess Shale – major fossil site located in Canadian Rockies

3. Paleozoic Era Ordovician Period (490-445 MYA)
1st vertebrates (in ocean) - jawless fish (filter feeders)
The lamprey of today is a parasite.
The hagfish is a scavenger.

4. Creatures of the Ordovician Period

5. Paleozoic Era Silurian Period (445-415 MYA)
Ozone (O3) layer formed which blocks harmful UV radiation; life could evolve on land.
1st land plants (mosses & ferns) followed by 1st land animals (invertebrates like spiders & scorpions).
1st jawed fish (later evolved into sharks-made of cartilage).

6. Paleozoic Era Devonian Period (415-360 MYA)
1st vertebrates on land – amphibians
Evolved from the lobed-fin fish which include the lungfish.

7. Paleozoic Era Devonian Period (415-360 MYA)
“Age of the Fish” (giant armored fish).
1st bony fish (scales and swim bladder for buoyancy).

8. View of Earth—Devonian Period

9. Life of the Devonian Period

10. Paleozoic Era Carboniferous Period (360-300 MYA)
1st reptiles
North America has a tropical climate creating coal deposits of today
Amphibians & insects dominate and become large
(dragon flies-1m wing span; cockroaches-10 cm long).

11. View of Earth—Carboniferous Pd

12. Paleozoic Era Permian Period (300-250 MYA)
Reptiles dominate.
Pangaea begins to form (dry climate)
Mass Extinction (95% of all marine invertebrates go extinct & 70% of all land species go extinct).
Early Permian reptiles, Cacops in front & Casea in back.
The middle Permian reptile, Anteosaurus.

14. View of Earth—Permian Period
Siberian Traps

15. FIVE Mass Extinction