How do we know what prehistoric environments were like? Objective Students will learn scientific methods used to reconstruct paleoclimatic conditions. They will also learn how to identify plants using a dichotomous key. Lastly, students will be able to compare past and present climate at Florissant. Background Part One: Leaf Identification Activity Paleontologists and/or paleobotanists use several methods to reconstruct paleoclimatic conditions. Fossils are the clues that paleontologists and paleobotanists use to find out information about the very distant past. Fossils are incredibly importan Duration: 60 Minutes.