Earth’s History Through Fossils

5.       What major event marked the end of the Paleozoic and Mesozoic eras according to the fossil record? Describe one theory that proposes to account for this.

a.       Both eras ended with a mass extinction of land and marine life on Earth. The Paleozoic era marked the end of trilobites (which at the time made up more than half the kinds of living things). The Mesozoic era marked the end of many land and marine animals, the end of the dinosaurs. One theory that explains the sudden loss of the dinosaurs states that Earth was struck by an asteroid.

6.       Briefly describe the principles and assumptions that form the basis of interpreting Earth’s history from the rocks.

a.       Through being able to read rocks on Earth, we are able to distinguish the visible/invisible characteristics and traits between certain time periods on Earth. Through carbon dating, we are able to pinpoint a timeframe when the fossil/rock was found.

7.       How are the numbers of the ages of eras and other divisions of the geologic time scale determined?

a.       The eras are predetermined based off of what happened in the period, what rose to “power”, and what ultimately died off.

8.       Describe the three basic categories of fossilization methods.

a.       There are three broad ways in which fossils are commonly formed, they include, preservation or alteration of hard parts, preservation of the shape, preservation of signs of activity.

9.       Describe some of the things that fossils can tell you about Earth’s history.

a.       Fossils can tell you actual or altered remains of plants and animals. It could be just simple evidence of former life, such as the imprint of a leaf, the footprint of a dinosaur, or droppings from bats in a cave. Fossils can tell you if a major event happened due to high concentrations of an out of this world object.

Read more: http://www.swagbucks.com/refer/smr0011