3/2 - 7th Grade Agenda Learning Objective: Discuss about how the dinosaurs became extinct. Collect HW: Reading & Notetaking p. 149 - 150 Classwork: Chap 8 Study Guide Video: Walking w/ Monsters before Dinosaurs Textbook Reading: 289 - 297 HW: Reading & Notetaking p.151 -152 Reminder: Chap 8 Test on 3/5 & 3/6

Reflection Prompt: What killed the dinosaurs? Which animal is the closest living relative of the dinosaur?

When was the earth created? Earth was formed about 4.6 billion years ago

What happened during Precambrian Time? Earth was formed about 4.6 billion years ago Earliest forms of life began about 3.5 billion years ago. They were single celled organism similar to bacteria About 2.5 billion years ago, organisms started to use the process of photosynthesis. This increased the amount of oxygen in the atmosphere.

Development of Atmosphere

What happened during Paleozoic Era 544 – 245 Million Years ago? Cambrian Explosion: At the beginning of the Paleozoic Era, a great number of different kinds of organisms evolved.

Cambrian Period – Explosion of Life in the sea (544 Million Years ago)

Devonian Period – Animals invade the land (408 Million Years Ago)

Permian Period (286 Million Years Ago)

End of the Permian Period, there was a mass extinction – (245 Million years ago) 95% of life in the oceans disappeared What do you think might have cause the mass extinction?

Mesozoic Era – Triassic, Jurassic Cretaceous Period (245 – 66 Million Years ago)

End of Cretaceous Period, there was another mass extinction (66 Million years ago) Where did the asteroid hit? Asteroid hit near southeastern Mexico (Yucatan Peninsula) When the asteroid hit Earth, the impart threw huge amount of dust and water vapor into the atmosphere

Which animal is the closest living relative of Dinosaurs? Birds are considered to be closest relatives of dinosaurs

Cenozoic Era – Age of Mammals (65 Million Years to Present)