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Exquisitely well-preserved fossils have been discovered from two Cambrian sites in the western USA, the Pioche Formation, and the Marjum Formation. The fossil Euarthropods, Alalcomenaeus, ‘thought’ to have lived around 500 million years ago, had dark staining down the central portion of their body. These were identified as the remains of the original central nervous system.

The team pointed out that the preservation of such tissues in fossils has come under intense scrutiny. They said, “the nervous system is prone to rapid decay, relative to other tissues, under controlled laboratory conditions”. However, the team were emphatic that people need to change their minds. They said it was time “to gravitate away from the preconception that nervous tissues are too labile [unstable] to become fossilized, as evidence keeps accumulating that neurological preservation is possible”.

Of course, such soft-tissue organs normally decay quickly. To be preserved they must have been rapidly covered in sediment. Such evidence points our thoughts towards Noah’s Flood, some 4,500 years ago. This provided the right conditions for the preservation of the fossil and the rock encasing it.

• Ortega-Hernández, J. and 2 others, Proclivity of nervous system preservation in Cambrian Burgess Shale-type deposits, Proceedings of the Royal Society B Biological Sciences, 11 Dec 2019.