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Fossil find proves complex life on earth 30 million years older than thought

The fossilized tracks of slug-like creature found in Uruguay are estimated to be 585 million years old.

uruguay fossil 6 29 2012Enlarge
The fossil of a mesosaurus — an aquatic reptile — is seen on April 11, 2012 in Pinamar, Uruguay. (PABLO PORCIUNCULA/AFP/Getty Images)

Researchers have reported finding evidence of the oldest animal known in existence, a slug-like creature measuring around a quarter of an inch long.

The finding of the slug's 585 million-year-old fossilized tracks in Uruguay, proved complex life evolved 30 million years earlier than previously established, according to numerous media reports.

Burrowing tracks from the animal, known as a bilaterian, were found in Uruguayan by University of Alberta geologists Ernesto Pecoits and Natalie Aubet, who along with colleagues reported the findings in the journal Science.

Bilaterans are symmetrical bilaterally, with their top side distinguishable from the bottom side.

Life has been proven to exist on Earth for about 3.5 billion years, according to Wired. However, "actual animals — multicellular, eukaryotic organisms — are only half a billion years old."

Previously, the oldest confirmed animal was another slug-like organism, the Kimberella, dated at 555 million years old and found in Russia.

"We now have the oldest physical evidence that multi-cellular life that could move was around between 600 million and 585 million years ago," said university geomicrobiologist Kurt Konhauser, an article co-authors, quoted in a report in the Calgary Herald.

The pattern of the track — found at bottom of a shallow ocean — indicates that the prehistoric species likely was searching for organic material to eat in silty sediment.

Konhauser, a geomicrobiologist, said the next step was to "find out how these animals evolved to the point where they were able to move about and hunt for food."

More from GlobalPost: New fossils suggest human ancestors originated in Asia, not Africa 

http://www.globalpost.com/dispatch/news/science/120629/evolution-life-earth-animals-million-prehistoric-uruguay