GeoLDgic Time ScaLE

Period

Epoch

Millions of

Years Ago

(approx.) Event Highlights

Cenozoic Quaternary Holocene 0.01

Pleistocene 1.8

Neogene Pliocene 5

Miocene 23 Paleogene Oligocene 35

Eocene 54

Paleocene 65 Mesozoic Cretaceous 145

Jurassic

The end of the last Ice Age and the beginnings of agriculture, animal domestication, and large-scale civilization Ice Ages

Dispersal of hominins out of Africa Emergence of bipedal hominins Monkeys radiate Large carnivores make their presence Apes evolve and radiate Monkeys and large running mammals emerge Radiation of modern mammal types First placental mammals First primates First flowering plants Dinosaurs climax and then go extinct at the end of the Cretaceous Dinosaurs are abundant First birds. First mammals (continued)

(continued)

Millions of

Years Ago

Era

Period

Epoch (approx.)

Event Highlights

Triassic

250

First dinosaurs. Conifers abundant

Paleozoic

Permian

Permian trilobites go extinct in an enormous extinction event

Carboniferous

350

First reptiles. Impressive coal forests

Devonian

400

Sharks and amphibians dominate and are abundant

Silurian

440

First terrestrial plants and animals

Ordovician

500

Invertebrates are dominant. First fishes

Cambrian

540

"Explosion" of animal life in the seas, includes trilobites

Precambrian

4,600

Life on Earth begins. Rare fossils of primitive aquatic plants. Some fossil algae date back to 2.5 billion years or more

Was this article helpful?

0 0

Post a comment