Across
- 2. The earliest vertebrates
- 6. The anterior clustering of specialized sensory organs
- 10. amphibians, repltiles, birds, and mammals (literally means four footed)
- 11. the advance bony fishes (the sleek shape)
- 13. "cartilage" and "fish" ((include the sharks)
- 14. include mostly carnivorous species
Down
- 1. "shell" and "skin"
- 3. all living agnathans _______ bone and possess 4 single nostril
- 4. Another evolving key vertebrate innovation
- 5. solid cylindrical body that often encloses the notochord
- 7. those without an amnion
- 8. fishes without jaws
- 9. some fossil agnathans
- 12. Series of separate bones or cartilage blocks firmly joined as a backbone that defines the major body axis.