This sounds like something that could still exist. An iron rich environment is necessary, or so it is assumed, and we know that this is uncommon. We know that these fossils occurred in an oceanic environment and were surely limited even then to rare iron rich oases. The conditions about these oases would surely be similar to that discovered around volcanic smokers.
In fact these smokers are rich in iron and it is very possible that these particular life forms make their home there. No one has looked yet.
This is also a viable answer to another geological question about magnetite. Most placer rivers contain a lot of magnetite in the form of black sand that is rarely if ever associated with an actual magnetite deposit. Could we be dealing with erosional release of magnetite in grain form from ancient sediments?
Or perhaps be assembled in deep metamorphic conditions before been released into the rivers. Recall that magnetite is almost as stubborn as gold and is a heavy metal. That is why it shows up in gold placer operations.
An informant of mine went to the beach once and noticed that the sand seemed greyer than normal even though it was obviously silica. He inspected it carefully and found no special evidence on anything other than silica.
He then pulled out his handy neodymium magnet (many times stronger than iron magnets) and swirled it around through the sand. He pulled out a great deal of super fine magnetite powder. He asked me what I thought might have caused this to happen. I had no good answer except to extend the classic not credible erosional idea. We now have the answer.
The existence of magneto bugs around smokers needs to be investigated and the possible existence today of their larger cousins also needs to be checked. Thirty years ago we did not know that smokers existed. Perhaps we should look?`
Paleocene/Eocene Global warming produces new life form
Researchers discover 'giant' magnetofossils from microorganisms that thrived 55 million years ago
Researchers from McGill University, along with colleagues from the California Institute of Technology, the Curie Institute in Paris, Princeton University and other institutions, have unearthed crystalline magnetic fossils of a previously unknown species of microorganism that lived at the boundary of the Paleocene and Eocene epochs, some 55 million years ago. Their results were published Oct. 21 in the Proceedings of the National Academy of Sciences.
The research might help scientists understand more thoroughly the potential effects of significant changes in the Earth's climate.
Though they are only some four microns long, these newly discovered, spear-shaped magnetite crystals (magnetofossils) – unearthed at a dig in New Jersey – are up to eight times larger than previously known magnetofossils. Magnetofossils are remnants of magnetite crystals produced by a type of bacteria called magnetotactic bacteria that are capable of orienting themselves along the direction of the Earth's magnetic field.
The new fossils are "unlike any magnetite crystal ever described," the study's first author Dirk Schumann – a graduate student at McGill's Department of Earth and Planetary Sciences – told Nature News.
"Previous reports suggested that the source of the magnetic signature in the boundary layer was a type of magnetite that was formed by the impact of a comet," said lead researcher and corresponding author Dr. Hojatollah Vali. "In our previous paper we proved that the magnetic signature comes from biogenic material.
"This is an entirely new class of organism that no one has reported before," explained Vali, a professor jointly appointed in McGill's Departments of Anatomy and Cell Biology and Earth and Planetary Sciences. "When my colleagues and I first discovered magnetofossils in deep-sea sediments in the mid-1980s, we knew already that magnetotactic bacteria produced magnetite and then we looked for the magnetofossils. In our new study, we discovered the magnetofossils first without knowing the organism."
This species of microorganism, explained Vali, lived during a period of abrupt global warming known as the Paleocene-Eocene Thermal Maximum (PETM), when worldwide temperatures rose by 5° to 6° C over a period of 20,000 years.
"What's very interesting is that we know the very specific time frame when these organisms existed," he said. "If you go below it, we don't find them, and if you go above it, we don't find them. Five degrees warmer may not seem like much, but there was much more iron available due to increased weathering.
The additional iron is required for the microorganism to produce the giant magnetofossils. It is clear that a similar abrupt global warming climatic event could have a severe impact upon our biosphere."
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