Fossil Detective Open Response

Every fossil tells part of a story, but how do scientists know which fossils are older than others? This reading passage introduces students to the detective work of comparing fossils found in different rock layers and locations. Readers discover how scientists use clues like rock layers, index fossils, and radiometric dating to determine the relative ages of fossils. Rather than relying on a single piece of evidence, researchers combine several methods to build a clearer picture of Earth’s long history.

Students strengthen reading comprehension by following explanations, comparing scientific methods, and understanding how multiple sources of evidence work together. The passage introduces important vocabulary such as index fossil, relative dating, rock layers, radiometric dating, and geologic evidence in language that’s easy to understand. Written in a conversational style, this worksheet encourages students to think like scientists who solve mysteries by carefully examining clues left behind millions of years ago.