Three orders of magnitude separate protein's longevity based on repeatedly measured decay rates and the evolutionary age assignment for this deposit that houses algal protein remnants.
If the Gunflint chert was emplaced only thousands of years ago, then these dilemmas evaporate.
They found the skullcap alongside stone tools, charcoal pieces, and other human remains.
Tools found included a Levallois point, burins, bladelets, overpassed blades, and Aurignacian tools.
But it has notable differences from those of other archaic humans found in the neighbouring Levant.
The discoverers concluded that: Its period of existence falls within that of another extinct humans, the Neanderthals.
But it has a relatively small brain size, which is estimated at around 1,100 m L, compared to modern human brain which is about 1,400 m L.
Heat can turn them into blackened, more-resistant compounds.
But the Gunflint chert contains signs of a cooler formation history.
In other words, it appears that none of the expected evolution has occurred across 1.88 billion supposed years.
The study authors wrote, "In addition, these microfossils still contain amide functional groups (absorption feature at 288.2 e V), which were likely to be involved in the proteinaceous compounds synthetized by the once living organisms." Biochemistry studies reveal that amide bonds have plenty of potential to perform spontaneous chemistry.