What did this organism do? Journal #55 What was the most predominant life-form that existed during the Precambrian Era? What did this organism do? What are the 6 periods of the Paleozoic Era?

Today we will identify major geologic and biological developments during the Mesozoic and Cenozoic Eras

End of the Paleozoic Era At the end of Paleozoic Era 90% of marine organisms and 70% of land organisms died. This episode when large numbers of organisms become extinct is known as a mass extinction This extinction happened because there were many new life-forms that appeared.

Mesozoic Era Earth’s surface changed dramatically during the Mesozoic Era. Pangaea broke into smaller continents and the tectonic plates drifted and collided. Creating mountains and shallow seas Conditions of the Mesozoic Era favored reptiles. Age of the Reptiles (Era) What are some examples of reptiles?

Mesozoic Era Earth’s surface changed dramatically during the Mesozoic Era. Pangaea broke into smaller continents and the tectonic plates drifted and collided. Creating mountains and shallow seas Conditions of the Mesozoic Era favored reptiles. Age of the Reptiles (Era) What are some examples of reptiles? Divided into 3 periods

Triassic Period Dinosaurs appeared Some were as small as squirrels and others were 30m long Most were 4-5m long New forms of marine invertebrates also evolved

Jurassic Period Dinosaurs became the dominant life- form 2 major groups of dinosaurs Saurishians (lizard hipped) Herbivores (brontosaurus) Carnivores Ornithischians (bird-hipped) Hervivores (stegosaurus)

Cretaceous Period Dinosaurs continued to dominate the Earth Tyrannosuarus rex Harosuars Ankylosuars Plant life became very sophisticated Flowering plants appeared Trees became abundant Maple Oak walnut

Mass Extinction The Cretaceous Period ended in another mass extinction Environmental changes may have caused this extinction (such as tectonic activity/volcanic activity) Impact hypothesis- giant meteorite crashed into Earth and raised enough dust to block the suns rays for many years. (Iridium is evidence)

Review What are the 3 periods of the Mesozoic Era? What Period did dinosaurs first appear? When did flowering plants first appear? What event marked the end of the Mesozoic Era?

Cenozoic Era Includes the present period Continents moved to their present day positions Movement of the tectonic plates formed mountains such as: Alps Himalayas Dramatic climate changes occurred At times, ice sheets covered 1/3 of land Temperatures decreased and new species adapted “Age of the mammals”

Cenozoic Era is divided into Epochs 2 periods: Tertiary Time before the last ice age Quaternary Began with the last ice age and includes present Cenozoic Era is divided into Epochs

Cenozoic Era is divided into Epochs 2 periods: Tertiary Time before the last ice age Quaternary Began with the last ice age and includes present Cenozoic Era is divided into Epochs

Your Assignment: Complete the graphic organizer Describe the environment of each period and identify at least one life form that existed during that time.