Scientists have discovered the preserved brain of a sea monster that likely existed 520 million years ago in the Lower Cambrian.

The creature has been called Lyrarapax unguispinus, and is believed to be one of the very first predators of its day.

Researchers discovered the brain at a site in Yunnan, south-west China, according to the Guardian. It has since been identified as a new member of the group of animals called anomalocaridads, which were once the top predators of the Cambrian seas.

A study on the brain was published in the journal Nature.

The animal featured a body armor, a cone-shaped mouth made of concentric plates, compound eyes, and spokes claws for hunting prey. It could measure up to six-feet long.

Researchers suggest the creature's brain was no more complex than those of tiny velvet worms living in jungles of the southern hemisphere.

"The top predator of the Cambrian had a brain that was much less complex than that of some of its possible prey and that looked surprisingly similar to a modern group of rather modest worm-like animals," lead-author Nicholas Strausfeld, of the University of Arizona's center for insect science, said to the Guardian.

Most anomalocaridid specimens found previously were poorly preserved, making it difficult to establish information about the creatures, according to co-author of the study, Peiyun Cong, a researcher at Yunnan University

Cong added that the brain likely shared similarities with velvet worms, as known as onychophorans.

"For the first time, we didn't have to rely just on the external form of the appendages and their sequence in the head to try and sort out segmental identities, but we can draw on the same tool kit we use for extant arthropods - the brain," said co-author Gregory Edgecombe, of the Natural History Museum, to Science 2.0

Anomalocaridids were extinct by the end of the Paleozonic Era, which was around 251 million years ago.

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