Across
- 5. the inside of birds bones is mostly what
- 7. where does most air go when a bird inhales
- 8. reptile like animals that maintain a constant internal body temperature
- 11. pollinate flowers in both tropical and temperate zones
- 13. duckbilled dinosaur that lived in small family groups
- 14. animals that can generate their own body heat
- 16. a vertebrate that has dry, scaly skin, lungs, and terrestrial eggs with several membranes
- 18. perching birds
- 19. ventral part of the shell
Down
- 1. period of mass extinction
- 2. what does reptile urine contain
- 3. ate leafy plants
- 4. removed from the blood by the kidneys
- 6. rely on behavior to help control body temperature
- 9. type of hunter that traveled in groups
- 10. when dinosaurs became dominant
- 12. what is the backbone of a turtle/tortoise
- 15. made of protein and develop from pits in the birds skin
- 17. helps birds break down food by grinding it