1.2bn-y-o lifeforms found in WA
By Roger Martin
10may02 News.com.au
A TEAM of Australian and Swedish scientists has found evidence that animal-like organisms
existed in a mountain range south of Perth at least 1.2 billion years ago, twice as far
back as previously thought likely.
The finding has the potential to challenge current understandings on when animals, if not
first roamed, at least first crawled on Earth.
The scientists say the tracks left by the organism, first discovered 11 years ago by an
honours student but only re-examined late last year, are similar to those some animals
could be expected to make today. They were found in the Stirling Ranges, about 400km south
of Perth.
Dating of the sandstone puts the find at between 1.2billion and 2 billion years old.
Animal-like organisms were thought to have first appeared on Earth fewer than 600 million
years ago.
Speaking from Stockholm last night, Swedish paleontologist Stefan Bengston said while the
research team could not be sure an animal had left the traces, the evidence suggested it
was a moving organism at the very least.
Dr Bengston said the findings suggested Earth's biosphere was far more complicated
1.2billion years ago than previously thought, and challenged current scientific orthodoxy.
The findings by the team from the University of Western Australia and the Swedish Museum
of Natural History are published today in Science magazine.
Perth geologist Birger Rasmussen, from the UWA's Department of Geology and Geophysics,
said the tracks were the oldest evidence of complex animal-like organisms.
"Potentially you are doubling the age of relatively complex animal-like
organisms," Dr Rasmussen said.
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