Life Through Time - Visual Timeline

This exhibit was researched, written and designed by Richard Paselk, Curator Emeritus.

A Timeline of the Eons’s, Era’s, & Periods

The development of life over the last 3,700 million years of the Earth's history is one of the great stories told by modern science. During most of this time living things left only traces to indicate their existence. Then, about 544 million years ago, during what is referred to as the Cambrian explosion, animals learned how to make hard, mineralized body parts. Suddenly rocks resulting from sand and mud deposits become laden with fossil remains, and our picture of ancient life grows enormously in scope and detail.

Scroll for Timeline

Archean and Proterozoic Eons

Precambrian - 4,570 to 542.0 Million years ago

Precambrian

4,570 to 542.0 Million years ago

The Precambrian encompasses nearly 90% of Earth's history, and almost a third of the history of the Universe. It begins with the formation of the Earth from the dust and gas of the solar nebula, includes the origin and early evolution of life, the beginning of plate tectonics, and the development of an oxygen atmosphere. It ends with one of Earth's great extinction events, making way for the development of modern plants and animals.

Museum case index:
Case #1 - Precambrian

Phanerozoic Eon

Phanerozoic Eon (542.0 Million years ago to present)

Paleozoic Era

542.0 to 251.0 Million years ago

Cambrian Period

Cambrian depiction - Artwork — **Cambrian Explosion**
*© G. Paselk, 2011*

542.0 to 488.3 Million years ago

Sudden appearance of fossil remains referred to as the Cambrian explosion. Marine animals with skeletons make their first appearance in shallow seas.

Read more:
Cambrian Description and Visuals

Museum Case Index:
Case #2 - Cambrian

Ordovician Period

Ordovician depiction - artwork — **Ordovician Radiation**
*© G. Paselk*

488.3 to 443.7 Million years ago

More complex shelled animals lived in seas during this period, which ended in a mass extinction.

Read more:
Ordovician Description and Visuals

Museum Case Index:
Case #3 - Ordovician

Silurian Period

Silurian - depiction - artwork — **Silurian Marinescape**
*© G. Paselk*

443.7 to 416.0 Million years ago

A warm climate and high sea level gave rise to large reefs, while on land simple land plants emerged.

Read more:
Silurian Description and Visuals

Museum Case Index:
Case #4 - Silurian

Devonian Period

Devonian depiction - painting — **Devonian Transition**
© G. Paselk

416.0 to 359.2 Million years ago

New predators such as sharks, bony fishes and ammonoids ruled the oceans. On land, scorpions, spiders, wingless insects and the first amphibians were starting to thrive.

Read more:
Devonian Description and Visuals

Museum Case Index:
Case #4 - Devonian

Devonian Audio Tour:
Submerge yourself in the aquatic adventures of the Devonian

Carboniferous Period

359.2 to 299.0 Million years ago

Mississippian Subperiod

Mississippian depiction - artwork — **Mississippian Crinoid Meadow**
*Sarah Hamblin*

359.2 to 318.1 Million years ago

During this period, sea lilies dominated the limestone seas and reptiles began to appear along with ferns.

Museum Case Index:
Case #6 - Mississippian Subperiod

Pennsylvanian Subperiod

Pennsylvanian depiction - artwork — **Carboniferous Tropical Forest**
*Treena Joi*

318.1 to 299.0 Million years ago

Coal swamp forests thrived during this period. A dragonfly ancestor lived then with a 29-inch wing inch.

Museum Case Index:
Case #7 - Pennsylvanian Subperiod

Permian depiction - artwork — **Permian Landscape**
*© G. Paselk*

Permian Period

299.0 to 251.0 Million years ago

Reptiles started to thrive in water and on land and conifer forests appear in this period. The Permian ended with greatest mass extinction event known in Earth's history.

Read more:
Permian Description and Visuals

Museum Case Index:
Case #8 - Permian

Mesozoic Era

251.0 to 65.5 Million years ago

Triassic Period

Triassic depiction - artwork — **Late Triassic Landscape**
*© G. Paselk*

251.0 to 199.6 Million years ago

The Permian extinction event was so severe that entirely new fauna and flora appear in the Triassic. Mammals and dinosaurs started to appear in this period.

Read more:
Triassic Description and Visuals

Museum Case Index:
Case #9 - Triassic Subperiod

Jurassic Period

Jurassic depiction - artwork — **Post storm cleanup**
*Gary Bloomfield*

199.6 to 145.5 Million years ago

Ammonites and dinosaurs made a huge comeback after near extinction at the end of the Triassic. The first bird fossils and flying pterosaurs showed up in the fossil record.

Read more:
Jurassic Description and Visuals

Museum Case Index:
Case #10 - Jurassic Subperiod

Cretaceous Period

Cretaceousn depiction - artwork — **End of an Era**
G. Paselk

145.5 to 65.5 Million years ago

The first flowering plants appeared at the end of the Mesozoic era, along with the extinction of dinosaurs, pterosaurs, mesosaurs and ammonoids, to name a few.

Read more:
Cretaceous Description and Visuals

Museum Case Index:
Case #11 - Cretaceous Subperiod

Cenozoic Era

65.5 Million years ago to present

Paleogene Period

Paleogene depiction - artwork — **Mid-Paleogene scene with grazing Mesohippus**
*Treena Joi*

65.5 to 23.03 Million years ago

Primitive mammals and birds began to flourish. The Paleogene includes what used to be the first part of the Tertiary.

The Paleogene has three divisions:

Paleocene Epoch (65.5 to 55.8 Million years ago)
Eocene Epoch (55.8 to 33.9 Million years ago)
Oligocene Epoch (33.9 to 23.03 Million years ago)

Read more:
Paleogene Description and Visuals

Museum Case Index:
Case #12 - Paleogene Subperiod

Neogene Period

Neogene depiction - artwork — **Neogene Scene**
*Kellan Korcheck and M. Royce*

23.03 Million years ago to present

Mammals evolved in oceans and on land. The Neogene case now includes Geologic time up to the present, covering what used to be the later Tertiary and the Quaternary, but is now the Neogene and the Quaterary.

The Neogene has two divisions:

Miocene Epoch (23.03 to 5.332 Million years ago)
Pliocene epoch (5.332 to 2.580 Million years ago)

and the Quaternary also has two divisions:

Pleistocene Epoch (11.700 yrs ago to 2.58 Million years ago)
Holocene Epoch (11.5 thousand years ago to present)

Read more:
Neogene Description and Visuals

Museum Case Index:
Case #13 - Neogene Subperiod

Neogene Audio Tour:

Listen to a detailed account of changing continents and the animals that inhabited them.

Note: If you have trouble hearing the audio tour try downloading first than playing. The audio goes with the image of the case below.

Picture of the Neogene Case at the museum

Prehistoric Mammals of the Cenozoic

65.5 Million years ago to present

Six cases highlight major mammal groups found in North America over the entire Cenozoic.

Carnivores

Diversify and Conquer

Museum Case Index:
Case #14 - Carnivores

Herbivores

Grass Roots Movement

Museum Case Index:
Case #16 - Herbivores

Giants

What's the Big Idea?

Museum Case Index:
Case #18 - Giants

Horses

Before the Cart

Museum Case Index:
Case #15 - Horses

Proboscideans

Unforgettable Faces

Museum Case Index:
Case #17 - Proboscideans

Pleistocene Extinctions

Close Encounters with Mankind

Museum Case Index:
Case #19 - Pleistocene

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