Researchers have discovered rare, living specimens of stromatolites, the oldest evidence of life on Earth, deep within a remote and protected World Heritage Area in Australia.
The discovery was made by a group of researchers including those from the University of Tasmania in Australia. They made the discovery while surveying peat- bound karstic wetlands, an unusual type of swamp, which occurs only in peaty soils underlain by limestone and similar carbonate rocks.
The stromatolites were previously unknown. According to Bernadette Proemse, a researcher from Tasmania University, “The ecosystem has developed around spring mounds where mineral-rich groundwater is forced to the surface by geological structures in underlying limestone rocks.”
"The find has proved doubly interesting because closer examination revealed that these spring mounds were partly built of living stromatolites," he said.
What are stromatolites?
Stromatolites are laminated structures of micro- organisms which have created layers of minerals using elements dissolved in the water in which they live.
Fossil stromatolites are the oldest evidence for life on Earth. They first appeared 3.7 billion years ago.
Significance of the discovery
• The stromatolites are rare because more advanced life forms such as aquatic snails feed on the micro-organisms required to form them.
• DNA analysis indicates that the Tasmanian stromatolites are micro-organism communities which differ from all other known stromatolites.
• The discovery provides clues on to why stromatolites thrived for millions of years but then virtually disappeared from all but a few exceptional places on Earth.
• The researchers believe that the highly mineralised water flowing from spring mounds is a critical factor in the ability of the stromatolites to survive in the Tasmanian wilderness because it challenges other forms of life.
• The mounds were found to be littered with the shells of dead freshwater snails.
These Tasmanian 'living fossils' are protected by the World Heritage Area and the sheer remoteness of the spring mounds.