1 / 7

Chapter 17 Section 3 Evolution of Multicellular Life

Chapter 17 Section 3 Evolution of Multicellular Life. Objectives: -Describe the key forms of life in the Paleozoic, Mesozoic, and Cenozoic eras. What has been learned from fossils. Several episodes of mass extinction that fall between time divisions

eddy
Télécharger la présentation

Chapter 17 Section 3 Evolution of Multicellular Life

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 17 Section 3Evolution of Multicellular Life Objectives: -Describe the key forms of life in the Paleozoic, Mesozoic, and Cenozoic eras

  2. What has been learned from fossils • Several episodes of mass extinction that fall between time divisions • Mass extinctionan event that occurs when many organisms disappear from the fossil record almost at once • The geologic time scale begins with the formation of Earth about 4.6 billion years ago.

  3. Precambrian – 87% of history • Oldest fossils about 3.4 billion years old resembling cyanobacteria stromatolites. • Stromatolites still form today in Australia from mats of cyanobacteria. • The stromatolites are evidence of the existence of photosynthetic organisms on Earth during the Precambrian. • Only prokaryotic life found in fossil record

  4. End of Precambrian – 543 MYA • Multicellular eukaryotes, such as sponges and jelly-fishes, diversified and filled the oceans

  5. Paleozoic and Cambrian Period • Paleozoic Era: more animals and plants • Early: fishes, aquatic vertebrates, ferns • Middle: amphibians • Late: reptiles and mass extinction • Cambrian Period: oceans teemed with many types of animals, including worms, sea stars, and unusual arthropods, trilobites

  6. Mesozoic - 248 MYA • Triassic Period: mammals and dinosaurs • Jurassic Period: dinosaurs and birds • Cretaceous Period: more mammals, flowering plants, but mass extinction of dinosaurs 65 MYA

  7. Chixulub Impact Event • Texas K-T Boundary

More Related