Geologic timeline

GEOLOGICAL TIMELINE

Earth through Time

BEGINNING

• Oxygen at 16.5%
• Carbon dioxide at 3809 ppm

END

• Oxygen at 26%
• Carbon dioxide at 579 ppm

PaleoZoic era

Age of Invertebrates 541 to 252 mya

Cambrian PERIOD 541-485 mya

Fossil Record shows explosion of life in the sea. Often called the "Cambrian Explosion" due to the relatively short time over which this diversity of forms appear. Evolution of animals with shells begins. Oxygen levels rose enough to support life

Ordovician Period 485 to 444 mya

Animals with bones appear, Supercontinent Gondwana, find marine invertebrates like brachiopods, trilobites, cephlapods and primitive fish.. Mass extinction at the end of this period occurs possibly caused by glaciation

Silurian Period 444-419 Mya

Early jawed fish appear, coral reefs fluorished leading to limestone deposits, and primitive vascular plants appear

Devonioan Period 419-359 mya

First amphibians, evolution of fish, Jawless fish and placoderms peak in diversity, dominated by ferns, Changes in atmosphere occur as oxygen increase and carbon dioxide decreases.Mass extinction occurs at end of period.

Carboniferous Period 359-299 mya

First reptiles, warm humid climate, coal abundant swamps, reptile diversity, Glaciation events during the late Carboniferous

Permian Period 299-252 mya

Gymnosperms present, reptiles dominant, supercontinent Pangaea formed causing changes in climate patterns and ocean ciculation

BEGINNING

• Oxygen at 24.3%
• Carbon dioxide at 672 ppm

END

• Oxygen at 22.6 %
• Carbon dioxide at 1276 ppm

Mesozoic era

Rise of mammals and birds

triassic Period 252-201 mya

First dinosaurs early mammals, stromatolites became widespread, Pangaea exists and mass extinction at end.

Jurassic Period 201-145 mya

Dinosaurs are abundant and diverse, break up of Pangaea with opening of Atlantic ocean and rich fossil record.

Cretaceous Period 145-66 mya

Early flowering plants, placental mammals, continents drift toward current positions, K-Pg exinction event

BEGINNING

• Oxygen at 22.7 %
• Carbon dioxide at 829ppm

END

• Oxygen at 21%
• Carbon dioxide at 400+ ppm

Cen0zoic era

Age of Mammals 66mya-present day

Tertiary Period 66-2.6 mya

Evolution of early primates and hominids, and uplift of the Rocky Mountains and the formation of the Great Rift Valley in Africa.

quaternanry Period 2.6 mya -present

Modern humans, extinction of large mammals and birds, ice age glaciation

800,000 mya

Age of oldest continous Ice core in Antarctica-provides record of atmosphere, temperature and GHG's

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