Across
- 3. modern snakes, lizards and ancestors constitute of lepidosaur
- 4. bone and fish
- 7. spiny forms
- 11. fishes with jaws
- 16. solid cylindrical body encloses the notochord
- 17. shell and skin
- 18. reptiles with two temporal fenestrae
- 19. early shark
- 25. round and mouth
- 26. mostly fossil lobe-finned fish
- 28. birds with talons
- 29. pointed noselike extension of the braincase
- 31. encases the embryo in a protective water compartment
- 32. fishes without jaws
- 33. one of the largest ray
- 36. previous called holosteans
- 37. plates and skin
- 38. scales covered with cosmine
- 39. vertebrates with amnion
- 40. vertebrates without amnion
Down
- 1. group of salamander
- 2. spiny root
- 5. cartilage and fish
- 6. fleshy finned-fish
- 8. tooth like microfossils
- 9. four-fouted vertebrates
- 10. external nostril opening
- 12. no feet
- 13. large group embracing the group of bony fishes
- 14. no tail
- 15. anterior clustering of specialized sensory organ
- 20. group of tetrapods
- 21. snakes and lizards
- 22. sharks and rays
- 23. ray finned-fish
- 24. rat fishes
- 27. usually covered with scales and bony plates
- 30. major innovation that evolved in vertebrates
- 34. openings on the surface of some animals
- 35. extended flap of skin