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Mass Extincition

By michaela.perry
  • 700 BCE

    The Ordovician Mass Extinction

    Graptolites were sea creatures. They were filter feeding animals and colony builders. Their demise of over a million years was caused by a short, severe ice age that lowered sea levels, triggerd by the uplift of the Appalachians.
  • 600 BCE

    The Devonian Mass Extinction

    Trilobites were the most diverse and abundant of the animals that appeared in the Cambrian explosion 550 million years ago. Their success was helped by their spiky armour and multifaceted eyes. The culprit was the newly evolved land plants that emerged, covering the planet during the Devonian period. Their deep roots stirred up the earth, releasing nutrients into the ocean. This triggered algal blooms which sucked oxygen out of the water, suffocating bottom dwellers like the Trilobites.
  • 500 BCE

    The Permian Mass Extinction

    Known as "the great dying", this was by far the worst extinction event ever seen; it nearly ended life on earth. the Tabulate Corals were lost during this period. Today's corals are an entirely different group. What caused it? A cataclysmic eruption near Siberia blasted CO2 into the atmosphere. Methanogenic bacteria responded by belching out methane.
  • 400 BCE

    The Triassic Mass Extinction

    Palaeontologists were baffled about the origin of these toothly fragments, mistaking them for bits of clams or sponges. But the discovery of an intact fossil in Scotland in the 1980s finally revealed their owner- a jawless eel like vertebrate names the Conodont which boasted this remarkable set of teeth lining its mouth and throat. They were one of the first structures built from hydroxyapatite. Of all the great extinctions, no clear cause has been found for this one.
  • 300 BCE

    The Cretaceous Mass Extinction

    Dinosaurs may have rules the land during the Cretaceous period but oceans belonged to the ammonites. But volcanic activity and climate change already placed the ammonites under stress. The asteroid impact that ended the dinosaurs reign provided the final blow. Only a few dwindling species of ammonites survived.