Across
- 2. the remains or impression of a prehistoric organism
- 5. group of mammals commonly thought of as pouched mammals
- 6. a class of fishes that includes those with a cartilaginous skeleton
- 9. the most primitive group under the archosaurs
- 10. means "ruling reptiles"
- 13. refers to paraphyletic pongids
- 15. the ray-finned fishes
- 16. other name for actinistia
- 18. class of air-breathing oviparous vertebrates, usually covered with scales or bony plates
- 20. two-footed locomotion
- 21. a superclass of jawless fish in the phylum Chordata
- 23. vertebrates that possess jaws
- 26. a phylum that includes all vertebrates
- 31. jawed fishes that are distinguished by the bony spines projecting in front of their fins
- 33. humans
- 36. bats
- 38. deep sea, mud-burrowing, eel-like scavengers
- 39. any member of a group of six species of living air-breathing fishes and several extinct relatives belonging to the class Sarcopterygii
- 40. includes snakes, lizards and a group of tropical or subtropical reptiles.
Down
- 1. sister group of the bony fishes
- 3. the bony fishes
- 4. an animal of a large group distinguished by the possession of a backbone or spinal column
- 7. interlocking bones that form the spinal column
- 8. bear embryos enveloped in extraembyronic membranes
- 11. a cold-blooded vertebrate animal of a class that comprises the frogs, toads, newts, and salamanders
- 12. first known aquatic reptiles
- 14. a class of vertebrates known as lobe-finned fishes
- 17. extinct agnathan chordates resembling eels
- 19. a class of armoured prehistoric fish
- 22. refers to hoofed animals
- 24. a four-footed animal
- 25. a bird with talons
- 27. specialized long hairs evident in carnivores
- 28. specialized feet used to stun or grasp prey
- 29. often called pterodactyls
- 30. the highest class of the subphylum Vertebrata comprising humans and all other animals that nourish their young with milk
- 32. a vertebrate class that includes the birds
- 34. a group of extinct reptiles
- 35. a delicate, transparent, sac-like membrane
- 37. complex, folded respiratory organs mostly found in fishes