Input (grade 5): The Ordovician (pronounced) is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3 Â 1.7 to 443.7 Â 1.5 million years ago.
Output (grade 7): The Ordovician period is the second of six of the Paleozoic era. It covers the time between about 488 million years to 444 million years ago.