article: The Earth could be suffering from shifts in its biochemical balance similar to those believed to have wiped out half of all life 200 million years ago. This is according to a British study that has discovered a catastrophic condition called 'marine photic zone euxinia' took place in one of the prehistoric oceans. This happens when the sun-lit surface waters of the ocean become devoid of oxygen and are poisoned by hydrogen sulphide. Life of the Triassic met a choking end in a runaway greenhouse climate, heating the seas into warm stagnation, according to a new study. Pictured is an artist's impression of what may have happened in the oceans 200 million years ago.  The study authors fear that the planet today could suffer similar consequences . Hydrogen sulphide is a by-product of micro-organisms that live without oxygen and is extremely toxic to most other lifeforms. The study authors fear that the planet today could suffer similar consequences caused by the amount of carbon dioxide being created through the burning of fossil fuels. A team lead by the University of Southampton studied fossilised organic molecules taken from sedimentary rocks that originally accumulated on the bottom of the north-eastern Panthalassic Ocean, which surrounded the continent of Pangaea. The rocks are now exposed on the Queen Charlotte Islands, off the coast of British Columbia, Canada. A team lead by the University of Southampton studied fossilised organic molecules taken from sedimentary rocks that originally accumulated on the bottom of the north-eastern Panthalassic Ocean. The rocks are now exposed on the Queen Charlotte Islands, off the coast of British Columbia, Canada . The experts found signs of bacteria which had suffered severe oxygen depletion and hydrogen sulphide poisoning which would have been caused by massive volcanic rifts in the Earth's tectonic plates. 'As tectonic plates shifted to break up Pangaea, huge volcanic rifts would have spewed carbon dioxide into the atmosphere, leading to rising temperatures from the greenhouse effect,' said Professor Jessica Whiteside. 'The rapid rises in CO2 would have triggered changes in ocean circulation, acidification and deoxygenation. The Panthalassic Ocean was the vast global ancestral Pacific ocean that surrounded the supercontinent Pangaea, during the late Paleozoic and the early Mesozoic eras . 'These changes have the potential to disrupt nutrient cycles and alter food chains essential for the survival of marine ecosystems. Our data now provides direct evidence that anoxic, and ultimately euxinic, conditions severely affected food chains. 'The same CO2 rise that led to the oxygen-depleted oceans also led to a mass extinction on land, and ultimately to the ecological takeover by dinosaurs, although the mechanisms are still under study.' She explained that although the Earth was very different during the Triassic period, the rate of carbon dioxide release from volcanic rifts are similar to those we are experiencing now through the burning of fossil fuels. Professor Whiteside added: 'The release of CO2 was probably at least as rapid as that caused by the burning of fossil fuels today, although the initial concentrations were much higher in the Triassic. 'The consequences of rapidly rising CO2 in ancient times inform us of the possible consequences of our own carbon dioxide crisis.' Meteor impacts contributed to wiping out species during mass extinction events on Earth . Ordovician-Silurian mass extinction - 443.4 million years ago . This was the third largest extinction in Earth's history, and had two peaks of dying separated by hundreds of thousands of years. Around 26 per cent of all marine families were wiped out and 60 per cent of all genera - an estimated 82-88 per cent of all species. Late Devonian mass extinction - 375-359 million years ago . Three quarters of all species on Earth died out in the Late Devonian mass extinction, though it may have been a series of extinctions over several million years. Around 22 per cent of all marine families, and 57 per cent of all genera were wiped out - an estimated 79-87 per cent of all species. Permian mass extinction - 252 million years ago . The Permian mass extinction has been nicknamed The Great Dying, since an incredible 96 per cent of species died out. All life on Earth today is descended from the 4 per cent of species that survived. Triassic-Jurassic mass extinction - 201 million years ago . There were two or three phases of extinction that made up the Triassic-Jurassic mass extinction event. 22 per cent of all marine families and 53 per cent of all genera - an estimated 76-84 per cent of all species. Cretaceous-Tertiary mass extinction - 66 million years ago . The Cretaceous-Tertiary mass extinction was the event that wiped out the dinosaurs. However, many other organisms perished including 16 per cent of all marine families and 47 per cent of all genera - an estimated 71-81 per cent of all species.
highlights: The rate of CO2 released from burning fossil fuels has increased .
  It is now similar to levels released from volcanic rifts during Triassic .
  This created disastrous condition dubbed 'marine photic zone euxinia'
  This happens when surface ocean waters become devoid of oxygen .
prediction: Earth 
   be suffering from 
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   to 
   life 200 million years ago 
   This is 
   to a British 
   condition called' marine photic zone euxinia' 
   place in 
   prehistoric oceans 
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   - 
   waters of the ocean become devoid of oxygen and are poisoned by hydrogen sulphide 
   greenhouse climate, 
   The study authors fear that the planet today could suffer similar consequences . 
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   fossil fuels 
   rocks 
   on 
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   . 
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