Fossils are very interesting things. On one hand, the creatures to whom they belonged lived and died way before we were even here, and on the other hand, they can still teach us so many things that we have no other way of knowing. This is why when you find a rarity, such as a completely fossilized ancient animal, you know that you’ve stumbled upon something big.
But it isn’t just entire animals that are precious coves of information. Sometimes, even an intact part of an extinct creature can teach us much about what was going on with the planet before we even started evolving into what we are today.
Fossilized nervous system
A team of researchers led by Dr. Javier Ortega-Hernández from the Universidad Nacional Autónoma de México stumbled upon one of the oldest Cambrian fossils – a 520 million year old arthropod nervous system.
The nervous system was immediately recognized by the bluish line dotted with dark splotches from which extend small, thin lines. It is pretty much the only intact nervous system found of a creature that lived around the same time when the Cambrian explosion took place.
Dated at over 520 million years old, the fossils offer enormous insight over how nervous systems evolved since before the Cambrian explosion. Belonging to an arthropod, it is immediately evident that it differs from the nervous systems of today’s arthropods, resembling those of velvet worms, which are cousins to modern day arthropods.
According to the lead author, the fossilized nervous system is somewhat of a combination between the Onychophoran’s (velvet worm) and the arthropods’. This is most likely because the Cambrian creature didn’t need to evolve all the specialized functions modern arthropods had to evolve to stay alive.
The Cambrian explosion
520 million years ago, when the owner of the fossilized nervous system lived, the seafloor was crawling with crustaceans, arthropods, and many other critters. This is because it was the beginning of the Cambrian explosion – the time in our planet’s history when a large number of animal groups all evolved during the same short amount of time.
Chengjiangocaris kunmingensis, as the critter in the study was called, grew to as little as six inches. It was one of the largest animals on Earth for that particular time, and scientists believed that it had as many as eighty pairs of legs. This made it scuttle about the ocean floor like a crab, shoveling sediment in its mouth in order to take out the nutrients.
Image source: Wikimedia