Scientists Stunned to Unearth 500-Million-Yr-Old 3D Cambrian Trilobites Fossils in Best Preserved Condition in Volcanic Ash

In 2024, researchers announced several new findings collected from certain Cambrian trilobite fossils from Morocco. These fossils stood apart from others of their kind because of their condition, stated the Natural History Museum. These fossils were stored in hot ash of seawater, in such a manner that researchers were able to analyze the remains in 3D. Findings regarding these fossils have been published in the journal Science. 

Researchers associated with the study claimed that these are some of the best-preserved three-dimensional trilobite fossils they have ever analyzed. Examinations unveiled that these remains collected from the High Atlas of Morocco were 500 million years old. Scientists labeled the collection as "Pompeii" due to its remarkable state.

Through the remains, researchers figured out features like the arrangement of legs and their soft tissues like mouthparts and internal organs. Experts think the creatures got enveloped in hot ash of seawater. Fossilisation happened quickly as ash turned into rock. This sequence of events is very similar to what happened with the inhabitants of Pompeii after the eruption of Mount Vesuvius, hence the name. Researchers were able to find even the shells of trilobite in the fossils.

Inside the ash molds, researchers detected many unknown segments of the creature's body, legs, digestive tract, and the hair-like structure attached to their appendages. The tract was filled with ash due to the possible situation in which the fossilization took place. Through these fossils, researchers are hopeful they will be able to examine an aspect that is yet to be explored in detail about these creatures. The relative scarcity of soft tissues in other fossils of trilobites has kept knowledge about their internal organs to a minimum. Experts want to understand more about soft tissues, through Pompeii which does exhibit those features.

Techniques like CT scanning and computer modeling of virtual X-ray slices on "Pompeii" unveiled that appendages attached at the edge of this creature's mouth had curved bases, which was not noted in past fossils. "Pompeii" also showcased that the assertion held by many experts that there were three pairs of head appendages behind a trilobite's antennae was wrong, instead they had four pairs. Examinations also revealed a previously undocumented part known as the labrum (a fleshy lobe covering the mouth) in the trilobite.

"The results revealed in exquisite detail a clustering of specialized leg pairs around the mouth, giving us a clearer picture of how trilobites fed. The head and body appendages have an inward-facing battery of dense spines, like those of today’s horseshoe crabs," co-author Harry Berks, from the University of Bristol added.

The hard calcified exoskeleton of trilobites makes them one of the most prominent creatures in the fossil record. Researchers have had plenty of opportunities to analyze these creatures, but none have been so detailed as these remains from the Cambrian period. "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," Dr. Greg Edgecombe, a paleontologist and author of this study, shared. "An unexpected outcome of our work is discovering that volcanic ash in shallow marine settings could be a bonanza for exceptional fossil preservation."

Researchers were astounded to witness such well-preserved fossils in a volcanic environment and believe more remains from similar settings should be analyzed. "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. I think pyroclastic deposits should become new targets for study, given their exceptional potential for trapping and preserving biological remains, including delicate soft tissues. These findings are anticipated to lead to significant discoveries about the evolution of life on our planet Earth," lead author, Prof Abderrazak El Albani shared.