![Picture](/uploads/4/3/5/6/43569555/2045834.jpg?250)
A modern horse (mammal)
A modern frog (amphibian)
The Geologic Time Scale
Welcome to the Duxbury Museum of Natural History website! Here we give you information on all the eras of Earths history. We hope you learn lots and have fun exploring our website! What is the Geologic Time Scale? The Geologic Time Scale is the progression of Earth’s history, starting at the beginning of time. Arthur Smith suggested the idea in 1913. The Geologic Time Scale documents the changes in Earth’s life and its geology. How did Scientists Create the Geologic Time Scale? Canal builder William Smith noticed a connection between rock layers that he was digging through. William found certain fossils in certain rock layers. Scientists finally realized the connection was that if a fossil was found in a certain rock layer, then that was the rock in which the fossil had lived on. Scientists noticed that that would mean they could study that rock layer to find out what other kinds of life lived there. How Do Scientists Decide When one Era Ends? Scientists focus on the major changes in climate, life, and geology to decide where one era ends and another begins. Say there was a mass extinction during an era, that would most likely mark the end of that certain era. This is because mass extinctions cause a huge change in earth’s life forms, an eras are heavily based on what is living at that point in time. Interesting Facts About The Geologic Time Scale Rodinia was the name of the first supercontinent in Earth’s history. There were a total of 8 mass extinctions in Earth’s history. North America was once covered in a warm, shallow sea! |
A modern Alligator (reptile)
|