Rhenium osmium dating
But the fact that it's more than a billion years old means that it's still by far the oldest recognizable multicellular complex organism.
Microscope images of the fossil Bangiomorpha pubescens show it closely resembles modern bangio red algae.
Since the introduction of NTIMS tech-nique, Re-Os isotope analyses have become possible for Osmium has a blue-gray tint and is the densest stable element; it is approximately twice as dense as lead and slightly denser than iridium.
Calculations of density from the X-ray diffraction data may produce the most reliable data for these elements, giving a value of 22.587 ± 0.009 g/cm 3 for osmium, slightly denser than the 22.562 ± 0.009 g/cm 3 of iridium; both metals are nearly 23 times Using Rhenium and Osmium in tank penetrators would mean using metals two to five times more precious than gold as tank ammunition.
In an email, he said people were skeptical that Bangiomorpha was really a red algae fossil because it was so old and there weren't any other eukaryotes similar to the ones who live today in the fossil record from that time.
"Most recognizable eukaryotes don't show up until around 800 million years ago." The reason it was so hard to tell how old Bangiomorpha was is that to measure the age of rocks, geologists typically rely on chemical techniques that can only be applied to layers of volcanic rock, Gibson said, and there wasn't much of that in the cliffs where the fossils were found.
Roger says the new, more precise age for Bangiomorpha measured by Gibson, Halverson and their colleagues is "definitely important — but it doesn't completely solve the problem." He said he still finds it "very concerning" that no other fossils of recognizable complex organisms besides Bangiomorpha older than 800 million years have been found to date.
It has also been used to measure the intensity of continental weathering over geologic time and to fix minimum ages for stabilization of the mantle roots of continental cratons.
Knowing precisely how old the fossil is also allowed the researchers to estimate that the very first plant likely evolved around 1.25 billion years ago.
Bangiomorpha, a microscopic fossil organism just fractions of a millimetre long, was first discovered beautifully preserved in layers of chert — effectively, glass — in cliffs on Somerset Island in Nunavut.
A Canadian-led study aims to settle the controversy over extraordinary Arctic fossils that represent the oldest known sexually reproducing organism and the oldest multicellular organism that used photosynthesis.
The fossil organism identified as a red algae called But the fact that its age could have been anywhere in a 500-million year span led to some controversy.