amphibians + reptiles

4. a young frog
8. a biological community of interacting organisms and their physical environment
9. tetrapod vertebrate animals
12. an extinct species known for its striking coloration and unique habitat in the cloud forests of Costa Rica
13. all extant and extinct amphibians and amniotes
16. the flexible membrane of skin possessed by most male frogs and toads
17. supercontinent that incorporated almost all the landmasses on Earth
18. a specialized respiratory organ that many aquatic animals use for aquatic gas exchange
19. mall slender-bodied amphibian with lungs and a well-developed tail
20. a tailless amphibian with a short squat body, moist smooth skin, and very long hind legs for leaping

1. a genus of toads
2. animals that neither develop nor retain a spine/back bone
3. ectothermic, anamniotic, four-limbed vertebrate animals
5. a geologic period
6. tetrapod vertebrate animals with an ectothermic metabolism and amniotic development
7. the process of transformation from an immature form to an adult form in two or more distinct stages
10. commonly referred to as a "cold-blooded animal
11. the scientific study of animals
14. a lizard-like amphibian with an elongated body and tail and short limbs
15. is the change in the heritable characteristics of biological populations over successive generations.