How did the Proterozoic eon get its name?
The Proterozoic Eon, meaning “earlier life,” is the eon of time after the Archean eon and ranges from 2.5 billion years old to 541 million years old. During this time, most of the central parts of the continents had formed and the plate tectonic process had started.
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What was life like in the Proterozoic period?

During the Proterozoic the atmosphere and oceans changed significantly. Proterozoic rocks contain many definite traces of primitive life-forms—the fossil remains of bacteria and blue-green algae as well as the first oxygen-dependent animals, the Ediacara fauna.
How did the Proterozoic eon start?
2,500 million years agoProterozoic / Began
What is the Proterozoic eon known for?
During the Proterozoic Eon, modern plate tectonics became active, and the ancient cores of the continents moved over wide areas of the globe, accumulating smaller fragments of crust and sometimes colliding with other large landmasses. The opposite also happened, leading to continental rifting.

What was the Proterozoic known for?
The Proterozoic Eon is known for hosting the transition to an oxygenated atmosphere. It came during the Mesoproterozoic, and several glaciations during the Neoproterozoic. During the late stages of the Proterozoic, from 635 to 542 mya, the evolution of abundant soft-bodied multicultural organisms occurred.
How did Earth look during the Proterozoic eon?
Highlights from the Proterozoic Eon In the Proterozoic Eon, Earth completely froze into a Snowball Earth or Slushball Earth. It was one of Earth’s many ice ages. Because of the oxygen-enriched atmosphere, the ozone layer thickened and cyanobacteria were threatened.
What major events happened in the Phanerozoic eon?
The time span of the Phanerozoic starts with the sudden appearance of fossilized evidence of a number of animal phyla; the evolution of those phyla into diverse forms; the emergence and development of complex plants; the evolution of fish; the emergence of insects and tetrapods; and the development of modern fauna.
How long did the Proterozoic eon last?
The Proterozoic Eon extended from 2500 Ma to 542.0±1.0 Ma (million years ago) so lasted about 2 billion years.
What plants lived in the Proterozoic era?
Some resemble seaweeds and may represent eukaryotic algae; we know from independent evidence that red algae and green algae appeared in the Proterozoic, probably over 1 billion years ago. There are tantalizing hints from trace fossils and molecular biology that animals may have appeared as much as 1 billion years ago.
What is the Phanerozoic era known for?
The Phanerozoic Eon is the current geologic eon in the geologic time scale, and the one during which abundant animal and plant life has existed. It covers 538.8 million years to the present, and it began with the Cambrian Period when animals first developed hard shells preserved in the fossil record.
How long did the Phanerozoic eon last?
about 541 million years
Phanerozoic Eon, the span of geologic time extending about 541 million years from the end of the Proterozoic Eon (which began about 2.5 billion years ago) to the present.
What is Proterozoic known for?
What was the Phanerozoic eon known for?
It is considered an Eon containing most of the history of life on earth based on the rock record which included fossils as an important tool. It is comprised of three geologic Eras including the Paleozoic, Mesozoic, and Cenozoic meaning ancient, middle, and recent respectively.