| 3850 – 750 | First Prokaryotic Organisms | Single-celled organisms with no nucleus. These are the Earth’s earliest forms of life. |
| 750 – 600 | First Eukaryotic Organisms | These are more complex single-celled organisms, each with a nucleus. |
| 600 – 542 | First Multicellular Organisms | This era marked the emergence of simple multi-cellular organisms. |
| 540 | Trilobites | Arthropods that were among the early prolific complex organisms. They dominated the oceans during the Paleozoic era. |
| 530 | First Vertebrates | Early forms of fish, the first organisms with a backbone. |
| 360 – 300 | Amphibians | These were the first vertebrates to walk on land, evolved from lobe-finned fishes. |
| 230 | Dinosaurs | A group of reptiles that appeared during the Mesozoic era. They were dominant terrestrial vertebrates. |
| 200 | Mammals | Mammals are a group of warm-blooded vertebrates constituting the class Mammalia. |
| 150 | Birds | Descendants of theropod dinosaurs, they have become the most diverse group of land vertebrates. |
| 130 | Flowers | The first flowering plants appeared, allowing for the proliferation of species that depended on them. |
| 60 | Primates | This group includes humans and our closest animal relatives. |
| 0.2 | Homo Sapiens | Our own species, the thinking human, emerged in Africa. |
