Scientists in Greenland discovered the fossilized brains and nervous system of an ancient animal that lived 520 million years ago. Kerygmachela kierkegaardi swam in the oceans and was a fearsome animal.

It is the ancient relative to today's arthropods.

Sea Monster Brains

Researchers uncovered 15 fossils in loose rocks that were damaged by weather conditions in the area. Previous fossils of Kerygmachela kierkegaardi didn't reveal much about the ancient creature, those fossils were deteriorated to the point where scientists couldn't learn much.

This new set of fossils are so well preserved that scientists are able to peer into its brain. Kerygmachela kierkegaardi lived during the period known as the Cambrian explosion, which occurred 541 million years ago. During this time, life on Earth began to diversify, most types of animals that are present now appeared during this period of time.

Kerygmachela kierkegaardi was a predator that went after smaller marine organisms. Its sized ranged from 1 to 10 inches. Kerygmachela kierkegaardi had two appendages on its head that it used to hunt, 11 small fins that helped it swim, and a long tail. Fossilized remains show that the creature didn't have a three-part brain as previously thought.

Kerygmachela kierkegaardi features a simple single-segment brain, unlike its modern relative arthropods which include animals such as spiders, lobsters, and insects. It does bear a resemblance to what scientists in the study believe panarthropods brains are like. Panarthropods include animals such as water bears and velvet worms.

Fossils show that Kerygmachela kierkegaardi features only the most prominent segment of the brain that is found in arthropods. Arthropods' brains are developed as a bundle of nerve cells close to their gut. Two more segments are developed later also close to their gut and then join the original segment to form their complex brain.

These findings are already being debated. Nicholas Strausfeld spoke to National Geographic to outline concern with the findings of the new study. Strausfeld says that researchers still don't know what the brains of water bears are like. So assuming that they have single segment brains is a leap for the team.

A post shared by Rebecca Gelernter (@nearbirdstudios) on Mar 9, 2018 at 10:32am PST

Fossilized Brains

Scientists previously believed that nervous tissue couldn't be fossilized. Recent findings have unearthed that brain tissue could be preserved in the fossil record. This will give scientists an idea of how animals' brains have evolved over time. One of the oldest known fossilized nervous tissues was found in 2012 in China, and it is of an ancient arthropod called Fuxianhuia protensa.

Researchers were concerned that this may have been a one-time event, but more fossilized remains of Fuxianhuia protensa were found in 2015. Paleontologists were able to recreate the process that led to this fossil.