Answer:
Hadean eon: origin of earth
Archaean eon: oldest fossils of prokaryotic cells appear
Proterozoic eon: oldest fossils of eukaryotic cells appear
Paleozoic era: first tetrapods and insects appear
            the cambrian explosion
Mesozoic era: dinosaurs evolve and radiate
             origin of mammals
Cenozoic era: humans appear
            major radiation of pollinating insects