Menendez Found the oldest fossils of plants
Saturday, November 20, 2010
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Found the oldest fossils of plants
From: http://www.lavoz.com.ar/ciudadanos/hallan-los-fosiles -more-old-to-plant
Ricardo Astini, a geologist at UNC, tiny fossilized spores found in the forest of Jujuy, the oldest evidence of terrestrial flora.
life came under the protection of the seas. More than three billion years the Earth's surface was very hostile. There was no oxygen and the sun was very strong because there was no ozone layer.
The first photosynthetic organisms of the ocean began to fill the atmosphere of oxygen and ozone. But the Earth was a desert. Then, the first plants began to colonize the sea coast.
That happened 470 million years ago, according to the latest study published in the scientific journal New Phytologist
the participation of the geologist Richard Astini, National University of Cordoba (UNC).
The discovery occurred in river sediments Chapels in the jungle Jujuy. There they found fossilized microspores five floors.Astini works in the Research Center Earth Sciences (Cicterra) of the UNC and CONICET. Also participating were researchers at the Argentine Institute of Snow Research, Glaciology and Environmental Sciences Mendoza (IANIGLA) and Liege University (Belgium).
This finding advances in 10 million years the emergence of land plants. Earlier fossils dating back 460 million years and were found in Czech Republic and Saudi Arabia.
"We worked consistently throughout the range. First we studied paleoenvironmental and we realized that the area was an estuary primitive terrestrial plant sites where anyone could grow, "explains Astini.
With these data, the researchers took samples of clay rocks, with more potential to preserve microfossils.
These rocks are treated with acids that brought light to the microspores.
"They have few persons microns (one millimeter a thousand microns) and are translucent. The reason is because they have preserved a cover that protects them. The same protection is an evolutionary trait that allowed plants to colonize the Earth's surface, "he says.
spores are a mechanism of plant reproduction. In the sea are naked, but out of it need a cover to protect them from sun, wind and oxygen that corrodes. Astini
explains that these microspores belong to a group of plants called liverworts, very simple, similar to mosses and still exist. "They are little girls with simple green leaves. Are not vertical, but creeping "he says.
He adds that the plants known to people, vascular, emerged 100 million years after the fossils found by him. Dating
. The age was determined from animal microfossils found in the same stratum and that he knows his age and evolution.
"stratigraphic evidence indicated they were from the Ordovician era (490 million to 440 million years ago), animal fossils allow us to better refine the period, "he said.colonization of the land surface by plants was a revolution in the history of life. By their presence, the climate became less hostile and allowed a large biodiversity of living organisms evolve, including humans.
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