1. PALEOZOIC ERA (542 Mya - 251 Mya) Andrea Villalba, Fabiola Ferrabone, Alfredo de Obaldia, Nicole Cortez

2. About 400 million years ago the surface of Earth looked like this. The continents united to form Pangaea.

3. Cambrian Period (542-488 Mya) Cambrian Explosion algae evolve most of the water is populated by armored arthropods (trilobites) Rodinia breaks up and becomes Gondwana Ordovician Period (488-444 Mya) abundance of marine species first arthropods go ashore to colonize Gondwana Ordovician-Silurian extinction Silurian Period (444-416 Mya) 4 continents corals, mollusks, and jawless fish evolution of vascular plants

4. Devonian Period (416 - 359 Mya) fish evolve into the first tetrapods first trees evolve first amphibians evolve 70% of the species go extinct in the Late Devonian extinction Carboniferous Period (359 - 299 Mya) tetrapods evolve into reptiles glaciation of Gondwana Permian Period (299 - 251 Mya) Pangaea is formed Panthalassic Ocean surrounds Pangaea PERMIAN EXTINCTION

5. Environment continuous continental shift (Rodinia fragments into Gondwana) inicially warm during the Cambrian, followed by an ice age Pangaea’s interior was likely very dry

6. Flora mainly aquatic during the early Paleozoic small vascular plants beside lakes dense forests during the Carboniferous Period Cooksonia

7. Fauna vertebrates appear in the form of fish during the Devonian period arthropods fish evolve into tetrapods reptiles increase in number by the late Permian Trilobite Dimetrodon Tiktaalik rosae

8. Mass Extinction (Permian Period) Theories 1.Siberian Traps eruptions produced ash clouds 2.Greenhouse effect triggered by the sudden release of methane from the sea floor

9. Mass Extinction Consequences 95% of marine species died 70% of terrestrial vertebrates became extinct recovery of life on Earth took 10 million years

10. Thank You!