Across
- 1. related families
- 3. A taxon composed of related phyla
- 5. One or more kingdom
- 7. smallest units of geological time
- 9. scientist who studies fossil
- 10. the grouping of objects or organisms
- 12. related classes
- 13. two or more periods
- 15. a record of earths history
- 17. similar related genera
- 18. evidence of an organism
Down
- 2. dating measure the age of rocks
- 4. longest unit of geological time
- 6. identifying species
- 8. related orders
- 9. the movement of several large plates
- 11. a named group of organisms
- 12. two or more epochs
- 14. Groups of species closely related
- 16. life the time it takes for half the isotope to decay