Mass extinctions are periods in Earth’s history when abnormally large numbers of species die out simultaneously or within a limited time frame. The Cretaceous-Tertiary (or K-T) extinction event is probably the most well-known to many people because it wiped out the dinosaurs, but many other mass extinction events have occurred throughout the history of the Earth. Some of these mass extinction events are even more devastating than K-T. The most severe occurred at the end of the Permian period when approximately 96% of all species disappeared. Many smaller scale mass extinctions of plants and animals have occurred as recorded in the fossil records. Discover more about Earth’s major extinction events below in the following case assignment.
STOP! Before you proceed, make sure that you have read the Home page for this module and followed the links provided there. This assignment requires information from those resources.
Case Part I: Geologic History of Earth
The first part of this assignment requires that you consider the history of extinction on our planet as explained in the links you viewed on the Home page. From the Museum of Paleontology tutorial on the Home page, answer the following questions. Use full sentences in paragraph form:
When you clicked on the ?bookmarks,? which events were listed and in what order (there were six)?
In the Geologic Time Scale section, images of which organisms are included in the Archaean time period?
Which three periods of time are described as ?Eras?? List the representative organisms included in the photos that appear when you click on each Era.
From the Sam Noble Museum Mass Extinctions