Scientists have discovered ‘prehistoric Pompeii’ with strangely well-preserved trilobites

The special degree of preservation, made possible by entrapment in volcanic ash, preserved not only the hard parts of the trilobite intact, but also rare soft tissues such as its digestive tract and its delicate hair-like structures.

You may have heard about the tragic story of Pompeii. The city was buried under a thick layer of ash and rubble during the eruption of Mount Vesuvius, which killed many people. Despite this terrible event, the volcanic material had a remarkable effect: it formed a kind of mold for the people and objects that covered it, allowing it to stand the test of time remarkably well. The ashes actually served as a preservative that preserved not only the bodies, but even details such as clothing and facial expressions. In the same vein, researchers have now discovered the best-preserved trilobite fossils ever, they wrote in the journal Sciences.

Trilobite fossils
This is a 500-million-year-old fossilized trilobite that was discovered in the High Atlas Mountains of Morocco. Until now, scientists’ understanding of this highly diverse group has been limited. This is mainly because the soft tissues are generally not well preserved. However, the Moroccan trilobites quickly fossilized when they were covered in hot ash in seawater. As the ash fossilized, their bodies were preserved to an unprecedented extent. Researcher Greg Edgecombe said: “A surprising result of our research is the discovery that volcanic ash in shallow marine areas could be an exceptionally valuable fossil preservation resource.”

Live animals
The researchers were amazed by the special degree of preservation. “I’ve been studying trilobites for almost 40 years,” Edgecombe says. “But I have never felt so strongly about looking at living animals as I do with these newly discovered specimens. I have studied a lot of soft tissues of trilobites, but the way these fossils have been preserved is truly amazing.”

Prehistoric Pompeii
It is no coincidence that researchers refer to these fossils as “prehistoric Pompeii.” In both cases, quick covering with ash helped preserve fine details and soft tissues that would otherwise have rapidly degraded. Just as the inhabitants of Pompeii were “frozen” in their daily activities by the ash, trilobites were also captured in their habitat, allowing scientists to obtain a detailed and well-preserved picture of their lives and anatomy.

keep it perfectly
The layer of ash perfectly preserved every part of the trilobites’ bodies, legs, and even the tiny hair-like structures along their limbs. The digestive tract was also preserved after being filled with ash. Even the tiny “lamp shells” attached to the trilobites’ exoskeleton remained in place, just as they were when the trilobites were alive.

Other discoveries
Overall, the fossils reveal fascinating new details about trilobite anatomy. For example, using CT scans and computer modeling of virtual X-ray slices, the researchers found that the appendages on the edge of the mouth have curved, spoon-like bases. These structures are too small to be seen in less well-preserved fossils. Previously, trilobites were thought to have three pairs of main appendages behind their long antennae, but the current study shows that there are actually four pairs. Also, a fleshy flap covering the mouth has now been documented for the first time in a trilobite. “The results reveal in great detail the presence of specialized appendages around the mouth, giving us a better idea of ​​how trilobites fed,” said co-author Harry Perks. “The appendages around the head and body appear to have a set of dense, inward-facing spines, similar to those found in modern horseshoe crabs.”

Trilobites are well-studied fossil marine animals because of their tough, calcified exoskeletons, which often stand the test of time. Over the past two centuries, paleontologists have described more than 20,000 different species. But the recent discovery of these beautifully preserved trilobite fossils is dramatically changing scientific understanding of this long-extinct group.

This discovery provides new and in-depth insights into these extinct marine animals. “As a scientist who has worked with fossils from different periods and locations, it was very exciting for me to discover fossils that were so well preserved in a volcanic environment,” says lead researcher Abdulrazak Al-Albani. More similar discoveries can be expected in volcanic deposits. The researchers are looking forward to examining more of these deposits more thoroughly. “I think it is definitely worthwhile to continue studying volcanic deposits, given their exceptional ability to capture and preserve biological remains, including delicate soft tissue,” says Al-Albani. “These discoveries are expected to provide important insights into the evolution of life on our planet.”