Evidence of fossilised brains in small arthropods 500 million years ago has been found

Evidence of fossilised brain tissue was found in arthropods that lived 500 million years ago according to a team of researchers. In case the confirmation comes, it would be a very important paleontological discovery because it would answer one of the most mysterious questions of paleontology: can nervous tissue, especially the brain, fossilize?

The discovery of these two fossils of Alalcomenaeus, an arthropod that lived between 543 and 490 million years ago, could help to find an answer to this question. In addition to the exoskeleton, in fact, also the soft tissues of the brain and nerves would have remained fossilized, tissues that in the vast majority of cases tend to disappear precisely because they are not hard unlike the skeleton (or teeth). Compared to bones, soft tissues degrade much earlier and therefore there is no time to start the fossilization process that leaves an impression.

In a new study, published in Proceedings of the Royal Society B, the research team describes the discovery of these fossil findings occurred, as explained by Javier Ortega-HernĂ¡ndez, a paleobiologist at Harvard University and one of the authors of the study, in exceptional circumstances.

One of the fossils, found in the Utha, has symmetrical spots along the perpendicular line of the body of the creature, spots reminiscent of those of the nervous system of some arthropods living today, including some species of crabs, spiders and scorpions. These same spots also contained good levels of carbon, a basic element of the same nervous tissue. And furthermore, these dark spots seem to be connected to the four eyes of the animal, which reminds once again to a nervous system.

The researchers then compared this fossil with two other fossils, one found in the same area and another in China, which seem to have the same traces as regards the possibility of fossilisation of brain matter.

Already in the past paleontologists had found a specimen of Alalcomenaeus for which it seemed that the fossilized imprint of the nervous tissue was also present in addition to that of the skeleton but the announcement of the discovery was greeted with a certain skepticism. Now this new discovery will give strength to the theory that also nervous tissues can fossilize at the level of footprints.

Another similar discovery had already occurred in 2012 when a team of researchers had found a fossilized Fuxianhuia protensa fingerprint that seemed to contain also the imprint of the brain.
According to some researchers, not the majority, it’s possible in fact, through a real stroke of luck, that the brain can fossilize and leave a footprint thanks to the fossilized footprints of the same bacteria that degraded it which would form a sort of biofilm.