Scientists have unveiled the most anatomically complete specimens of Cambrian trilobites ever found, showcasing these ancient creatures in stunning 3D images. The pristine fossils, dating back to the Cambrian period (541 million to 485 million years ago), were discovered in 2015 encased under layers of volcanic ash from the Cambrian Tatelt Formation in Morocco. This volcanic burial preserved even the animals’ delicate soft tissue, revealing anatomical features never observed before.
“These new specimens not only preserve the antennae and walking legs, but also mouth structures and even the entire digestive system in three dimensions (3D),” explained Dr. [Paleontologist’s name], a paleontologist from the University of New England and corresponding author of the study, in an email to Live Science.
The researchers unearthed two species of trilobites at the site – Protolenus (Hupeolenus) sp. and Gigoutella mauretanica. To meticulously examine these long-extinct arthropods, the scientists employed X-ray microtomography – an imaging technique used to view the interior of an object slice by slice – to piece together a virtual 3D model. These models captured “the finest details including the outer surface of the animals, each segment of their bodies, their legs, and even the hair-like structures along their appendages,” explained Dr. [Sedimentologist’s name], a sedimentologist at the University of Poitiers and lead author of the study, in an email to Live Science.
The exceptional preservation and high-quality 3D images allowed scientists to observe previously unseen parts of trilobites, such as the mouth structures of Protolenus (Hupeolenus) sp. This included “a fleshy lobe covering the mouth, called a labrum, which was documented for the first time in trilobites,” said Albani.
These trilobites were remarkably well-preserved for half a billion years thanks to the volcanic ash from an ancient eruption that entombed the creatures in a manner similar to the preservation of Pompeii after the A.D. 79 eruption of Mount Vesuvius. “As volcanic ash is so fine-grained, not unlike talcum powder, it can mold the tiniest anatomical features on the external surface of these animals, right down to the bristles on the walking legs,” explained Paterson. “This, coupled with rapid burial, allowed for the amazing 3D details to be preserved in these trilobites,” Paterson added.
The volcanic ash also played a crucial role in preserving the animals’ internal structures. In the case of the specimen with its entire digestive system intact, the unfortunate trilobite likely ingested ash in the water before its demise. This ash prevented the soft tissues from degrading, according to the study published Thursday (June 27) in the journal Science.
Trilobite fossils are found globally and are easily recognized by their segmented bodies composed of a hard exoskeleton. This tough exterior is often well-preserved in fossils, enabling scientists to identify 22,000 trilobite species spanning a vast period of time, according to the study. These new discoveries provide an unprecedented glimpse into the anatomy and lives of these fascinating creatures that roamed the Earth millions of years ago.
