Era - a system of chronology.

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era - it is a large time period, historical period.So-called system of chronology, as well as the beginning of this era.The entire history of our planet can be divided into periods.Between themselves, they differ in certain climatic and geographical changes, as well as a significant breakthrough in the development of flora and fauna.Many people wonder what to eat and what age they are.Consider the basic stages of development of the Earth.

Archean era

At this time our planet was formed, period lasted about a billion years.Life on Earth has not been in the ocean chemical reactions between acids, alkalis, salts.Archean era gave rise to the protein substances.It was then that began to emerge living organisms.

Proterozoic era

Huge duration period of the planet, which lasted about 2 billion years.At this time, develop algae and bacteria, the organisms acquire their own bodies, they become multicellular.Era - a time period when there is something new, distinguished stage of the formation of Proterozoic deposits of iron ore.This period is characterized by the fact that all life processes occur in the ocean.

Paleozoic era

This is the period difference of the permanent changing climatic conditions, it is divided into 6 stages.At this time, developing flora and fauna, there are many species of fish.Along the banks grow conifers, ferns.Around the middle of the era of the first amphibians appeared in the form of reptiles, beetles, grasshoppers.The period is characterized by constant upheavals, changing the shapes of the continents.

Mesozoic Era

Stage consisting of Triassic, Jurassic and Cretaceous periods.The Mesozoic era - is the emergence of land and sea turtles, frogs, shrimp, new varieties of coral.Is dominated by reptiles and dinosaurs.In the middle age there are the first representatives of modern birds and insects.The Cretaceous period saw the extinction of the dinosaurs and pterosaurs.

At this time, improved climatic conditions, with the result that the land is covered with greenery.On land there are the first species of cypress and pine trees, and flowering plants.In the Mesozoic era are beginning to cooperate insects and flora.During this period, the continents acquire new forms and dimensions, as a result of the split formed the island.Atlantic Ocean is increasing in size, flooding large tracts of land.

Cenozoic era

«How many years it takes a period in which humanity lives?" - Often ask people this question.The Cenozoic era (it lasts to this day) began about 66 million years ago.She distinguished the advent of modern birds, mammals and angiosperms, of course, man.By the middle of the era we have formed almost all the main groups of the kingdoms of nature.At this time there are steppes and meadows, new types of grasses, shrubs.Also in nature formed the main types agrotcenozov and biogeocenosis.Man begins to adapt to the environment, to use nature to meet personal needs.That people later changed the organic world.The Cenozoic Era is divided into three periods: the Paleogene, Neogene and Quaternary.She continues today.

considered age divided by climatic and geographical characteristics.But there are other systems of chronology.For example, saying "our era", many imply stage, which originates from the Nativity.Also, people allocate industrial, technotronic and other periods that something distinguished, have changed the way people think about the world, changed the attitude to living organisms.