| A | B |
|---|
| chordate | The phylum whose members have a notochord, a nerve chord and slits in their throat area at some point in their lives. |
| endotherm | An animal whose body controls and regulates its temperature by controlling the internal heat it produces. |
| notochord | A flexible rod that supports a chordate's back. |
| ectotherm | An animal whose body does not produce much internal heat. |
| fish | An ectothermic vertebrate that lives in the water and has fins. |
| swim bladder | An internal gas-filled organ that helps a bony fish stabilize its body at different water depths. |
| habitat | The specific environment in which an animal lives. |
| amphibian | An ectothermic vertebrate that spends its early life in water and its adulthood on land, returning to water to reproduce. |
| reptile | An ectothermic vertebrate that has lungs and scaly skin. |
| paleontologist | A scientist who studies extinct organisms, examines fossil structure, and makes comparisons to present day organisms. |
