‘Remarkably preserved’ 500-million-year-old sea creature discovered

A sea creature that lived millions of years ago has been discovered in a “remarkable state of preservation” by scientists.

Even though trilobites swam the oceans some 500 million years ago, researchers said the animals still look as though they “died yesterday”.

The creatures met their end after becoming completely encased in ash after a volcanic explosion, preserving soft tissue and other parts of the body in pristine condition.

Dr Greg Edgecombe, a palaeontologist at the Natural History Museum, said: “I’ve been studying trilobites for nearly 40 years, but I never felt like I was looking at live animals as much as I have with these ones.

“I’ve seen a lot of soft anatomy of trilobites, but it’s the 3D preservation here that is truly astounding.”

Trilobites are some of the most widely studied fossil marine animals, with more than 20,000 species identified over the past 200 years.

Dr Edgecombe said studying trilobites is important because they provide scientists with “one of the most comprehensive datasets” for analysing the evolutionary history of an extinct species.

The creatures were also geographically diverse, making them excellent index fossils for geologists calculating the age of the rocks in which they are found.

While trilobite fossils are widely available, well-preserved soft tissue is harder to find because bacteria and other micro-organisms hasten decomposition.

The current trilobites, which range between 10mm and 26mm long, were found in the High Atlas mountain range in Morocco.

Scientists nicknamed them “Pompei trilobites” because they met an end similar to the inhabitants of Pompeii after the eruption of Mount Vesuvius.

Scans showed most body parts were well preserved, including the digestive system.

Even small “lamp shells” attached to the trilobites’ external structure were attached by fleshy stalks as they were in life, the researchers said.

The scientists also discovered that appendages at the edge of the mouth had curved spoon-like bases, a feature that was not visible in other fossils because they were so small.

Harry Berks, from the University of Bristol, said these “exquisite” details give “a clearer picture of how trilobites fed”.

He added: “The head and body appendages were found to have an inward-facing battery of dense spines, like those of today’s horseshoe crabs.”

A soft tissue structure around the mouth called the labrum was also documented for the first time in trilobites.

Professor Abderrazak El Albani, a geologist based at University of Poitiers, in France, said: “As a scientist who has worked on fossils from different ages and locations, discovering fossils in such a remarkable state of preservation within a volcanic setting was a profoundly exhilarating experience for me.”

He said volcanic ash deposits could also be potential targets for new discoveries of ancient species.

The findings are published in the journal Science.