A fossil web site in Morocco has been referred to as the “Pompeii of trilobites” because it comprises sublimely detailed fossilised moulds of the creatures, preserved after a pyroclastic ash movement from a volcanic eruption round 509 million years in the past.

“My jaw fell onto the desk,” says John Paterson on the College of New England in Armidale, Australia. “I’ve by no means seen the extent of element preserved in these fossil trilobites. They’re completely, no query, the best-preserved trilobites ever discovered.”

Trilobites are marine arthropods that existed from round 520 million years in the past till practically 252 million years in the past. We all know of greater than 22,000 species and numerous fossils have been found, however these are usually simply their powerful exoskeleton. The creatures’ mushy components are solely discovered on uncommon events, and are at all times flattened and broken.

Nonetheless, the second Paterson noticed scans and pictures of trilobite fossils collected in 2022, from south-west of Marrakesh, in Morocco, he knew they have been one thing particular.

“On one of many extra full specimens, the entire appendages are preserved in 3D, proper all the way down to the bristles on their strolling legs,” he says.

To this point, Paterson and his colleagues have collected 4 specimens, every solely round a centimetre lengthy, representing two species from the Tatelt formation in Morocco. Two of the 4 trilobite specimens belong to the genus Protolenus, however the researchers are not sure whether or not they belong to a brand new species. The opposite specimens are Gigoutella mauretanica.

Pompeii is prized by archaeologists as a result of ash from Mount Vesuvius rapidly descended on the Roman metropolis, preserving its buildings and inhabitants. As soon as the ash cooled and fashioned into rock, every of the our bodies decomposed, leaving a cavity that represents an ideal mould. The identical factor occurred to the trilobites, says Paterson.

The workforce scanned the moulds with a micro CT scanner and was in a position to create good 3D pictures of the creatures. “With these specimens, you may see something you need at any angle,” says Paterson.

The scans have allowed the workforce to resolve some necessary particulars of trilobite anatomy which have been lengthy debated, such because the construction of its feeding equipment. For one of many people, it will need to have swallowed ash because it died as a result of its digestive tract is full of volcanic materials and, therefore, clearly preserved.

One other perception was how the creatures used their legs. “They’ve very gnarly-looking spines on the internal facet of their legs,” says Paterson. “These would have acted like a shredding software on no matter was their prey. In different phrases, they chewed with their legs and pushed the meals from their legs as much as their mouth.”