The Original landmass of the Earth; the supercontinent known as Pangaea shown in one of it's configurations.
Long before dinosaurs ruled over the Earth; one large continuous area of land, known as Pangaea that existed during the Paleozoic and Mesozoic eras about 250 million years ago encompassed the largest portion of the world's landmass. A single enormous ocean surrounded Pangaea and was known as Panthalassa.The Pangaea theory states that all present continents were once amassed together and collectively known as a 'supercontinent' called Pangaea. The word 'Pangaea' means 'all lands' in Greek, accurately defining the way the continents were 200 millions years ago before it split up.
It was during this period of Earth's past that "geological records show that the Earth experienced a global catastrophe.... "A huge Siberian volcano destroyed the world's forests 250 million years ago in what scientists say was the worst extinction event the planet has ever witnessed, new research has disclosed... It rained fire and acid rain for hundreds of thousands of years and killed 90 percent of all life, including plants and vegetation.... Earth scientist, Prof Mark Sephton, of Imperial College London, said:: "Ironically, the worst imaginable conditions for plant and animal species provided the best possible conditions for the fungi to flourish."
"It created the perfect storm."
He added: "Acid rain fell on Earth for hundreds of thousands of years which killed the trees and plants and allowed the fungus to take over the planet."
"It has been conjectured that "basalt lava flows were unleashed on the continent from a location centred on what is present day Siberia. Up to 96 per cent of all marine species and 70 per cent of land species became extinct. Traditionally, scientists had thought that land plants weathered the catastrophe without much loss.
"Today's findings suggest that much of the vegetation on Pangaea did not survive and that the world's forests were wiped out, according to the researchers. Geological records show that there was a massive spike in the population of Reduviasporonites across Pangea as the Permian period came to an end. The scientists suggest that this means that there was in increase in the supply of wood for them to decay.
"The tiny organisms that covered the planet more than 250 million years ago appear to be a species of ancient fungus that thrived in dead wood, according to new research published October 1 in the journal Geology.
"The researchers behind the study, from Imperial College London and other universities in the UK, USA and The Netherlands, believe that the organisms were able to thrive during this period because the world's forests had been wiped out. This would explain how the organisms, which are known as Reduviasporonites, were able to proliferate across the planet.
"Researchers had previously been unsure as to whether Reduviasporonites were a type of fungus or algae. By analysing the carbon and nitrogen content of the fossilised remains of the microscopic organisms, the scientists identified them as a type of wood-rotting fungus that would have lived inside dead trees."
"The team reached their conclusions by analysing the carbon and nitrogen content of Reduviasporonites under state of the art microscopes and comparing the results with those from modern fungi.
They discovered that Reduviasporonites and modern fungi show similar chemical characteristics."
"Fossil records of Reduviasporonites reveal chains of microscopic cells and reflect an organism that lived during the Permian-Triassic period."
An enlarged image of Reduviasporonites. Scientists believe extinct fungus species capitalised on a world-wide disaster and thrived on early Earth.
(Credit: Image courtesy of Imperial College London)
"The team suggest that the basalt lava, which flowed during Permian-Triassic catastrophe, unleashed toxic gases into the air. The gases had a dual effect, producing acid rain and depleting the ozone layer. The outcome was the destruction of forests, providing enough rotting vegetation to nourish Reduviasporonites so that they could proliferate across Pangaea.
"The team reached their conclusions by analysing the carbon and nitrogen content of Reduviasporonites using a High Sensitivity Mass Spectrometer and comparing the results with those from modern fungi. They discovered that Reduviasporonites and modern fungi show similar chemical characteristics."
Although there are a number of scientists who do not agree and remain skeptical of scientists who claim that they have identified an ancient fungus that flourished about 250 million years ago, feeding on dead trees as it spread across the planet. Those remains point to a crucial clue that some believe to equate with the identity of what killed off much of Earth's plant and animal life at the time.
Scientists Mark A. Sephton, Henk Visscher, Cindy V. Looy, Alexander B. Verchovsky, and Jonathan S. Watson.believe: "One of the most controversial biological proxies of environmental crisis at the close of the Permian is the organic microfossil Reduviasporonites. The proliferation of this disaster species coincides with the mass extinction and numerous geochemical disturbances. Originally Reduviasporonites was assigned to fungi, opportunistically exploiting dying end-Permian forests, but subsequent geochemical data have been used to suggest an algal origin. We have used high-sensitivity equipment, partly designed to detect interstellar grains in meteorites, to reexamine the geochemical signature of Reduviasporonites. Organic chemistry, carbon and nitrogen isotopes, and carbon/nitrogen ratios are consistent with a fungal origin. The use of this microfossil as a marker of terrestrial ecosystem collapse should not be merely discounted. Unequivocally diagnostic data, however, may have been precluded by post-burial replacement of its organic constituents."
"The team analyzed carbon and nitrogen isotopes from samples of Reduviasporonites. As the researchers report today in Geology, those analyses identified chemicals unique to Reduviasporonites, whose reign spanned the Permian and Triassic periods, and other compounds associated with dead tree matter, within the same microfossils. Astrobiologist and lead author Mark Sephton of Imperial College London says the analyses show that the organism fed on dead wood. In addition, he notes, the Reduviasporonites microfossils have been found in sediments deposited at the P-Tr boundary all across what was then Pangaea. "This suggests that we are looking at something truly global in effect."
"Sephton explains that for Reduviasporonites to be so common at the P-Tr boundary, they must have thrived on a disaster that brought about "a dramatic change in the environment." The most likely cause, he says, is a massive release of sulfur dioxide and other noxious gases from volcanic eruptions. Those gases would have caused highly acidified rain, enough to poison most of the planet, killing trees and creating a global feast for Reduviasporonites. "When things turned really bad," Sephton says, "they were most at home."
"It's a good story if it turns out to be true, says paleontologist C. Kevin Boyce of the University of Chicago in Illinois. The analyses of the carbon isotopes provide the "strongest evidence" of a fungal lifestyle for Reduviasporonites, he says. They do "a much better job than previous work" in identifying components of Reduviasporonites versus bits of organic matter from fossilized dead trees. So was Reduviasporonites a fungus? "Maybe," Boyce says. "What [the team's] work does is at least reopen that door."
Citations: Mark A. Sephton, Henk Visscher, Cindy V. Looy, Alexander B. Verchovsky, and Jonathan S. Watson. Chemical constitution of a Permian-Triassic disaster species. Geology, October 2009; v. 37; no. 10; DOI: 10.1130/G30096A.1; Geology, October 2009 v. 37 no. 10 p. 875-878. Telegraph.co.uk: Published: 12:08PM BST 01 Oct 2009.
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