This activity (located on page 4 of the PDF under GPS: Baby Dinosaurs Activity) is a full inquiry investigation to determine the age of fossils based on where they are discovered. Groups of learners will dig for fossils embedded in a cake of multiple layers, carefully excavating each stratum and eventually preparing a chart from their notes for discussion with the group. The two main lessons from this exercise are that fossils from different layers come from different eras and that multiple interpretations of incomplete fossil evidence are possible. Relates to linked video, DragonflyTV GPS: Baby Dinosaurs.