Study the image about geologic time. Geochronological scale Paleogene Cenozoic many types of mammals diatrima Neogene Quatemary BUNKS smiodon mammoth human During which period did humans first appear on Earth? O Quaternary O Neogene O Paleogene O Cenozoic Study the image about geologic time . Geochronological scale Paleogene Cenozoic many types of mammals diatrima Neogene Quatemary BUNKS smiodon mammoth human During which period did humans first appear on Earth ? O Quaternary O Neogene O Paleogene O Cenozoic