Portion of ancient Australian chert microstructures definitively pseudo-fossils


Share post:

A team of scientists including Carnegie’s Dina Bower and Andrew Steele weigh in on whether microstructures found in 3.46 billion-year-old samples of a silica-rich rock called chert found in Western Australia are the planet’s oldest fossils. The purported fossils have been a heated scientific controversy for many years. The team asserts that at least a portion of the microstructures are actually pseudo-fossils. Their findings are published in Astrobiology.

Portion of ancient Australian chert microstructures definitively pseudo-fossils
Different types of imaging show the microstructure that was originally designated 
as the fossil Eoleptonema apex [Credit: Dina Bower & Andrew Steele]

More than two decades ago, microscopic filamentary structures, less than two dozen micrometers in length, found in Australia’s Apex chert formation were declared to be fossils of photosynthetic bacteria from the Archean eon. These alleged microfossils were obviously of great interest to scientists interested in the origins of life on Earth as well as those trying to determine the best way to look for life on other planets.

But since then, subsequent research involving Owen Green at Oxford University (who is also a co-author on this study) has called these claims into question, putting forward the idea that the structures are fossil-like mineral formations, but not actually the remains of life. Debate about the authenticity of the Apex chert microfossils has raged over the last several years.

The research team — which also included Marc Fries of the NASA Johnson Space Center and John Lindsay (now deceased) of the Lunar and Planetary Science Institute — analyzed the orientation of the quartz crystals (quartz is a form of silica, which makes up chert) surrounding the alleged microfossils in order to determine whether the crystals and microstructures were both formed as part of the same geological processes.

“Based on our findings, we think that the Apex fossil that was designated as Eoleptonema apex in the originally described samples that we re-studied here was actually formed when a series of quartz grains cracked and was filled in with carbon-rich material to create a sheet-shaped structure within the larger crystal,” Steele explains.

The source of the carbon could have been biological, or abiotic, but this structure itself is not a fossil, the team asserts.

“Studies have shown that 60 percent of the originally described alleged microfossils were found in material that is younger than its host rock, E. apex being one such example. This study further develops a new technique in order to study the indigeneity of the microfossils in the rock and shows without a doubt that this particular example is a pseudo-fossil. The other microstructures in the primary rock (i.e. the oldest part of the rock) should now be analyzed critically in order to prove that similar processes have not been responsible for the formation of those features,” said Bower.

Source: Carnegie Institution [February 16, 2016]



Related articles

A human touch for ancient manuscripts in Italy

Ancient manuscripts are treated like hospital patients at a famous book restoration institute in Rome that has worked...

One million year old bird bones found in Australia’s Nullarbor Plain

Scientists believe they have found the complete fossilised skeleton of a prehistoric wedge-tailed eagle during excavations on the...

Another ancient university’s remains found in Bihar

Remains of an ancient university have been discovered in Bihar, which is home to Nalanda and Vikramshila universities,...

A mile deep, ocean fish facing health impacts from human pollution

Deep-water marine fish living on the continental slopes at depths from 2,000 feet to one mile have liver...

Study sheds light on the function of the penis bone in male competition

A new UCL study examines how the baculum (penis bone) evolved in mammals and explores its possible function...

Hubble sees an aging star wave goodbye

This planetary nebula is called PK 329-02.2 and is located in the constellation of Norma in the southern...

New species of duckbilled dinosaur found

The newly described Probrachylophosaurus bergei, a member of the Brachylophosaurini clade of dinosaurs, has a small flat triangular...

Fish of dinosaur era with unique ‘hook-shaped sail’ on its back

A 90-million-year-old fossil fish, which has been on display at the Perot Museum of Nature and Science in...