- A dinosaur is a kind of extinct animal
- A bone is a part of some animals
- An example of a fossil is the bones of an extinct animal
- Therefore, the bones of dinosaurs are an example of fossils

- The bones of dinosaurs are an example of fossils
- Index fossils can be used to determine the approximate age of other fossils in that area
- Hence, index fossils can be used to determine the approximate age of the fossils of the bones of dinosaurs

Therefore, index fossils can be used to determine the approximate age of the fossils of the bones of dinosaurs
[Question]A scientist finds the bones of a dinosaur. What could help the scientist determine the approximate age of the dinosaur bones?
[Context]- A dinosaur is a kind of extinct animal 
- Index fossils can be used to determine the approximate age of other fossils in that area 
- A bone is a part of some animals 
- An example of a fossil is the bones of an extinct animal