biologia

By 3l3yn3
  • Period: 4600 BCE to 570 BCE

    Precambriam

    -Guide fosil: Stromatolites
    -Geological events:The planet Earth formed, the continents joined to form Rodinia and then fractured; there was extensive volcanic activity.
    -Climatic events: a primitive atmosphere with traces of oxygen and an ozone layer; the first ice age occurred.
  • First forms of life
    3800 BCE

    First forms of life

    The first life forms appeared, which were very simple organisms, such as bacteria.Life developed in water, and the atmosphere lacked oxygen.
  • More complex organisms
    2500 BCE

    More complex organisms

    More complex organisms emerged, such as eukaryotes. Thanks to photosynthesis, oxygen levels in the atmosphere increased. The first multicellular organisms appeared at the end of this period.
  • Period: 570 BCE to 280 BCE

    Paleozoic

    -Guide fosssil:Trilobitos
    -Geological events: Two mountain ranges formed, and Pangaea II came into being.
    -Climatic events: The Earth's environment transitioned from warm and humid to cold with severe glaciations towards the end of the period. The climate became drier, coinciding with the formation of Pangaea.
  • First arthropods and cephalopods
    485 BCE

    First arthropods and cephalopods

    During the period, the Cambrian explosion occurred, when many new life forms appeared.Life developed only in the sea, and animals whit hard parts such as shells and skeletons emerged
  • Fish age
    443 BCE

    Fish age

    Marine life diversified greatly, and the first fish appeared.The first land plants also emerged, although they were very simple.This period ended with a mass extinction.
  • First expansion
    419 BCE

    First expansion

    After the extinction, life recovered.Land plants developed further, and the first animals on land, such as arthropods, appeared.Jawed fish also emerged.
  • Age of amphibians
    359 BCE

    Age of amphibians

    This period Is known as the age of fishes, as they diversified greatly. The first amphibians and the first forests appeared.At the end of the period, there was another major extinction.
  • Fern forest
    299 BCE

    Fern forest

    Large forest formed, giving rise to coal.There was a lot of oxygen in the atmosphere, which allowed for large insects. The firs reptiles appeared
  • Great extinction
    252 BCE

    Great extinction

    Reptiles became the dominant group, and many species adapted to dry climates. Eventually, the largest mass extinction in history occurred, wiping out most living things.
  • Period: 252 BCE to 66 BCE

    Mezosoic

    Guide fossil:sefalopodos marinos
    Geological events:Pangaea fragments, forming the Atlantic and Indian Oceans, leading to intense volcanic activity, a possible meteorite impact, and a division of power.
    Climate events:The climate was very dry after the continents joined together, creating Pangaea; there was a greenhouse effect (warm climate, no ice ages).
  • First dinosaurs
    225 BCE

    First dinosaurs

    After the great Permian extinction, life began to recover.The first dinosaurs and the first mammals, which were small, appeared.Reptiles diversified greatly, and gymnosperms were the dominant plants.
  • First birds
    135 BCE

    First birds

    Dinosaurs became the dominant animals.The first birds appeared, and there were many marina reptiles.Vegetation was abundant.
  • Fifth mass extinction
    66 BCE

    Fifth mass extinction

    Flowering plants(angiosperms) appeared and spread. Dinosaurs continued to dominate, but at the end of the period, a great mass extinction occurred, wiping out the non-avian dinosaurs and many other species.
  • Period: 66 BCE to

    Cenozoic

    -Guide fossil:Nummulites
    -Geological events:The Himalayas and the Alps form, South and North America join, the continents also separate, the Canary Islands form, and finally, continental drift (orogeny) ends.
    -Climatic events: The polar ice caps form, there is a prolonged period of global cooling, and glaciations cause the rise and fall of sea levels; the last glaciation, known as the Ice Age, occurs.
  • Paleogene
    23 BCE

    Paleogene

    After the extinction of the dinosaurs, mammals and birds diversified greatly. New groups appeared, and the climate was initially warm, though it later began to cool.
  • Neogene
    2 BCE

    Neogene

    Many modern mammals evolved, and grasslands expanded. The first hominids, ancestors of humans, appeared.
  • Quaternary

    Quaternary

    Homo sapiens appeared.Several ice ages occurred, causing the extinction of many large mammals and significant changed in ecosystems.