History of Earth Timeline

Earth History

BC= Billion years

Oldest Sedimentary Rock

3,800,000,000 BC - 04/16/2013

Made from igneous, metamorphic, or other sedimentary rocks. When these rocks are exposed at the earth’s surface they begin the long slow but relentless process of becoming sedimentary rock. First sedimentary rock found in Greenland 3.8 billion years ago.

First Blue and Green Algea

3,400,000,000 BC - 04/16/2013

The first bacteria was cyanobacteriabacteria, cyanobacteria are larger than most bacteria, and may secrete a thick cell wall. More importantly, cyanobacteria may form large layered structures.
3.4 billions years ago.

Communities of Organisms form "mats"

2,700,000,000 BC - 04/16/2013

Microbial mats are specialized microbial communities that are composed mainly of photosynthetic prokaryotes.

Evidence of Microbial Life

2,100,000,000 BC - 04/16/2013

Carbon isotopes and fossil stromatolites are the evidence to early microbial life.

Eukaryotic Emdosymbiosis Occurs

1,400,000,000 BC - 04/16/2013

Large cells are present suggesting eukaryotic emdosymbiosis has occur and sexual reproduction is now present. 1.4 billion years ago.

First Known Multicellular Organisms Form

1,200,000,000 BC - 04/16/2013

First known multicellular organisms are formed. Are very jelly-fish like. 2.1 billion years ago.

Beginning of the Cambrian period and first abundant fossils

550,000,000 BC - 04/16/2013

Fossils from species like brachiopods, tribolites, anthropods are formed. 550 million years ago.

Beginning of the Ordovician period and first backboned animals

500,000,000 BC - 04/16/2013

During this time period most continents came together to form super-continent Gondwana, also the first sea animals came to land; horse shoe crabs began to mate and spawn on land. 500 million years ago.

Beginning of the Silurian period and the first land plants

440,000,000 BC - 04/16/2013

Corals and other marine organism thrived, also first land plants; didn’t have leaves at first but then turned into mosses and ferns. 440 million years ago.

Beginning of the Devonian period and the first amphibians

400,000,000 BC - 04/16/2013

Many fish and amphibians appeared during this time period; ray-fish and lobe-finned boney fish are examples. 400 million years ago.

Coal Age Forests

350,000,000 BC - 04/16/2013

Giant spore producing trees are abundant. 350 million years ago.

The First Reptiles

345,000,000 BC - 04/16/2013

During carboniferous period, evolved from water animals; Hylonomous is the oldest know reptile. 345 million years ago.

Beginning of the Permian Period

285,000,000 BC - 04/16/2013

Last period of the paleozoic era, largest mass extinction recorded in history of earth, Pangea was formed. 285 million years ago.

Beginning of the Triassic period and first dinosaurs

245,000,000 BC - 04/16/2013

Started after mass extinction, beginning of Mesozoic Period and age of reptiles, dinosaurs evolved from archosaurs (lizard type things). 245 million years ago.

Beginning of the Jurassic period and first mammals

205,000,000 BC - 04/16/2013

Pangea starts to drift apart, and many dinosaurs and first birds start to appear. 205 million years ago.

First birds

150,000,000 BC - 04/16/2013

Jurassic period, developed from dinosaurs, Aves was the biological class these birds were in. 150 million years ago.

Beginning of the Cretaceous Period

140,000,000 BC - 04/16/2013

Warm climate and many shallow inland seas. New birds, mammals, and flowering plants appeared. Many dinosaurs stayed on land and reptiles were in the water. 140 million years ago.

Massive extinction which ends the age of the dinosaurs

65,000,000 BC - 04/16/2013

Cretaceous-Tertiary (K/T) Extinction Event. This may have been caused by an iridium-rich meteorite or comet hitting Earth and causing dust to block out the sun. 65 million years ago.

First primates and mammals diversify

60,000,000 BC - 04/16/2013

Mammals/primates develop different characteristics. Ex: flat nails, thumbs, better vision. 60 million years ago.

First Elephant-like Animals

38,000,000 BC - 04/16/2013

Phosphatherium, small pig sized elephant. 5 million years after dinosaurs went extinct. 38 million years ago.

Camel, horse, big cat and new species on grasslands

30,000,000 BC - 04/16/2013

The animals crossed the ice bridge to Eurasia, and then dispersed to North America. 30 million years ago.

Beginning of the Pliocene Epoch

5,000,000 BC - 04/16/2013

This was a time of global cooling after the warmer Miocene. The cooling and drying of the global environment may have contributed to the enormous spread of grasslands and savannas during this time. The change in vegetation undoubtedly was a major factor in the rise of long-legged grazers who came to live in these areas.

FIrst human like animals

2,000,000 BC - 04/16/2013

Studies show we are related to an ancestor that looked like a squirrel. The ankle bones show that it had a mobile ankle joint like primates today that live in trees. 2 million years ago.

Beginning of the Pleistocene epoch and ice ages

1,000,000 BC - 04/16/2013

Many genera and even species of Pleistocene conifers, mosses, flowering plants, insects,mollusks, birds, mammals, and others survive to this day. Yet the Pleistocene was also characterized by the presence of distinctive large land mammals and birds.

Last ice age

10,000 BC - 04/16/2013

Around 130,000-110,000 years ago the Earth's climates were generally much like those of today, though somewhat warmer and moister in many regions. As the cold grew more severe, the Earth's climate also became drier because the global 'weather machine'.
10,000 years ago.