Life on Earth likely began in the ancient oceans. Millions of years ago, there were marine organisms who died and, in certain circumstances, left a record of their lives as fossils. Scientists are able to study prehistoric ocean life by finding fossils… sometimes very far inland! Some of these prehistoric sea creatures went extinct when they couldn’t adapt to changes in their environment, and some were successful and have modern-day relatives. These extant species have sometimes changed a lot, and sometimes very little. Depending on the fossils, we can see evidence of the environment the animal experienced all those years ago. In this activity, students will gather evidence to support an explanation of whether an organism went extinct, or has evolved into a modern organism. They will also address and model the fossilization process and excavation techniques used by paleontologists.