1. Paleozoic Era 570,000,000 yrs ago to 225,000,000 yrs ago Life starts in the seas and moves onto land Six periods: Cambrian Ordovician Silurian Devonian Carboniferous Permian

2. Paleozoic Era Cambrian Period (570-500 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 (500-435 MYA) 1 st 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 (435-395 MYA)  Ozone (O 3 ) layer formed which blocks harmful UV radiation; life could evolve on land.  1 st land plants (mosses & ferns) followed by 1 st land animals (invertebrates like spiders & scorpions).  1 st jawed fish (later evolved into sharks-made of cartilage).

6. Paleozoic Era Devonian Period (395-345 MYA)  1 st vertebrates on land – amphibians Evolved from the lobed-fin fish which include the lungfish.

7. Paleozoic Era Devonian Period (395-345 MYA)  “Age of the Fish” (giant armored fish).  1 st 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 (345-280 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 (280-225 MYA) Early Permian reptiles, Cacops in front & Casea in back. The middle Permian reptile, Anteosaurus.  Reptiles dominate.  Pangaea begins to form (dry climate)  Mass Extinction (90% of all marine invertebrates go extinct & 70% of all land species go extinct).

13. View of Earth—Permian Period

14. FIVE Mass Extinction