| A | B |
|---|
| Amphibians | These animals begin their lives in water and breathe with gills. As adults, they live on land and breathe with lungs. |
| Bipedal | The ability to walk upright on two legs. |
| Birds | A class of animals with feathers, wings and beaks. They lay eggs with hard shells and have hollow bones to reduce the density of their skeleton. |
| Cenozoic | Age of the Mammals |
| Ectothermic | Organisms that rely on the environment for body heat. (Cold-Blooded) |
| Endothermic | Organisms that produce their own body heat. (Warm-Blooded) |
| Eon | The largest division of geologic time |
| Fish | An ectothermic vertebrate that lives in the water and has fins. |
| Geologic Era | One of four time periods representing a time of major sediment deposition and movement; Precambrian, Paleozoic, Mesozoic, and Cenozoic. |
| Geologic Period | An extended amount of time marked by a series of related events. These are also called Epochs. |
| Hominid | A member of a biological group including human beings and related species that walk upright. |
| Mammal | Animals that have hair and produce milk for their young. |
| Marsupials | Mammals whose immature offspring complete their development in an external pouch. |
| Mesozoic | Age of the Reptiles |
| Paleozoic | 570 mya-245 mya; "Ancient Life"; first plants, fish, amphibians, reptiles (watertight skin, incubate eggs out of water) |
| Precambrian | Name for the time in earths early history that accounts for ninety percent of earth's time, but only unicellular organisms lived; autotrophic prokaryotes enriched the atmosphere with oxygen. |
| Primate | Any of the various mammals of this order have a highly developed brain, eyes facing forward, a shortened nose and muzzle, and opposable thumbs; lemurs, lorises, monkeys, apes, and hominids. |
| Reptile | Vertebrates that live on land, scales cover body, lay eggs, cold blooded. |
| Social Structure | A pattern of organized relationships among groups of people within a society. |
| Technology | The means by which a society provides its members with those things needed and desired. |
