Across
- 1. Organisms that live at or near the seafloor
- 3. Transgressive sequence characterized by black shale deposits
- 7. Chordates and echinoderms share a RADIAL or SPIRAL embryonic cleavage (pick one)
- 10. During a regressive event, erosion leaves behind an ________.
- 12. The second known transgressive event in North American history
- 15. Early vertebrate with a central nervous system, skeletal rod and filtering organs
- 16. The first transgressive event and cratonic sequence in North American history
- 17. Location where soft-bodied organisms from the Paleozoic were found in Canada (2 words)
- 18. Rocks found in regions that were, at one time, swampy
- 19. Period of the Paleozoic that had an “explosion” of new organisms
- 20. The type of deposit found behind reef complexes
Down
- 2. Geologist who drew the first geologic map of England, last name
- 4. Paleozoic period where the earliest freshwater fish emerged
- 5. Period of the Paleozoic that is characterized by "great" and rapid biodiversity
- 6. Period that had the third, and largest recorded, mass extinction event
- 8. Evolutionary development that allowed reptiles to move onto land (2 words)
- 9. Deposits that have repeating marine and nonmarine layers
- 11. Paleozoic period characterized by rapid evolution of land plants
- 13. The second known supercontinent in Earth’s history
- 14. Extremely common three-lobed arthropod in the Cambrian