Look: Ancient predator found 500 million years later with brain still intact

The eyes have it by Jennifer Walter Updated: Feb. 20, 2024 Originally Published: July 8, 2022 Animation by Sabrina Cappelli © Royal Ontario Museum

Shutterstock 500 million years ago, the most fearsome creatures in the ocean were radiodonts — predatory, shrimp-like organisms that reached just a few feet in length.

One of the smallest to ever exist was Stanleycaris hirpex. The species ranged in size from one to just over eight centimeters long. Animation by Sabrina Cappelli © Royal Ontario Museum

And while it may be tiny, S. hirpex is helping researchers unravel huge evolutionary mysteries.

Art by Sabrina Cappelli © Royal Ontario Museum

Photo by Jean-Bernard Caron, © Royal Ontario Museum Writing this week in the journal Current Biology, researchers announced the discovery of 268 previously unreported S. hirpex specimens from the Burgess Shale fossil site in Canada.

The specimens are so well-preserved that their brains and nervous system tissues are still intact.

Animation by Sabrina Cappelli © Royal Ontario Museum

Photo by Jean-Bernard Caron © Royal Ontario Museum Radiodonts are often found in fragments, making the discovery of so many whole-body fossils a jackpot for researchers.

Photo by Jean-Bernard Caron © Royal Ontario Museum “Since most radiodonts are only known from scattered bits and pieces, this discovery is a crucial jump forward in understanding what they looked like and how they lived.” Jean-Bernard Caron, study co-author and curator at the Royal Ontario Museum, in a press release.

Norman Celis / 500px/500px/Getty Images The once-plentiful predators also shed light on how their modern-day successors — insects and spiders — developed brains and eyes.

S. hirpex boasts a large third eye on its head, which was a surprise to researchers. A third eye has never been seen in a radiodont before.

ozgur kerem bulur / 500px/500Px Plus/Getty Images Even 500 million years ago, the visual capabilities of these animals were already highly developed like their modern kin, explained study co-author Jean-Bernard Caron in a press release .

S. hirpex also has a segmented head and brain, which is similar to the ones many insects have today.

Art by Sabrina Cappelli © Royal Ontario Museum That revelation can help researchers piece together the evolution of certain traits — and better appreciate what was passed down from ancient ancestors.

Look: Ancient predator found 500 million years later with brain still intact

And while it may be tiny, S. hirpex is helping researchers unravel huge evolutionary mysteries.

The specimens are so well-preserved that their brains and nervous system tissues are still intact.

S. hirpex boasts a large third eye on its head, which was a surprise to researchers. A third eye has never been seen in a radiodont before.

S. hirpex also has a segmented head and brain, which is similar to the ones many insects have today.

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