The Last Supper of a Trilobite. Czech paleontologists studied the prehistoric creature’s diet

A paper on the diet of these endangered marine arthropods and their role in prehistoric ecosystems has been published in a prestigious scientific journal. NatureCharles University’s Faculty of Science announced this week.

The unique three-dimensionally preserved fossil known as the Rokikon Ball was discovered over a century ago by local collector Karel Holup. However, its secrets have only just been revealed by using the most modern imaging technique with the help of a synchrotron.

After its discovery in 1908, the trilobite fossil entered the collection of the Rockigan Museum, today’s Dr. Bohuslav Horak (part of the West Bohemian Museum in Pilsen).

“I remember this part from my childhood,” noted the study’s first author, Peter Croft, from the Faculty of Science in England. “Because it was my grandfather’s favorite fossil, and that’s why its photo once hung in the paleontology study at the Rockigan Museum, where he helped out.”

More than 100 years ago, paleontologists realized that small shells found in the broken part of the trunk could represent the remains of preserved food in the digestive tract. But they could not be studied because they would destroy the rare fossil.

The breakthrough came with the use of the high-end technology of synchrotron tomography, which allows us to scan high-density objects – including rocks – with a resolution of one-thousandth of a millimeter. The rocicon trilobite was one of the first Czech fossils studied at the European Synchrotron in Grenoble, France.

“Getting slices like most people know from a hospital CT scan is just the first step. This is followed by manual differentiation of individual structures using reconstruction software. The resulting 3D model of the fossil is photographed in a virtual photo studio, highlighting the depth of the image, resulting in a more informative illustration,” explained Valeria Vaskaninova from the UK’s Faculty of Natural Sciences.

The scientists reconstructed the contents of the stomach and intestines and were able to identify the Ordovician animals (Ordovician is the geological formation of the oldest protozoan – note. Red.) saw the trilobite Bohemolichas incola on the sea floor. They found that his digestive tract was completely filled with calcareous shells and fragments of marine invertebrates such as bivalves, bivalves and echinoderms.

According to the researchers, the trilobite simply “ate what stood in its way” from the reconstruction, be it carrion or live prey, including solid shells. He didn’t worry about the composition of his food, but focused mainly on small bites or what he could nibble on.

Paleontologists consider it remarkable that the thin-walled limestone shells were not even partially dissolved in the digestive tract. For them, this indicates that they are not exposed to an acidic environment.

“The neutral or slightly alkaline environment of the digestive system is also observed in present-day crustaceans and arthropods, indicating a very ancient common origin of arthropod digestion,” they said.

After the trilobite died, it became food. The researchers found many tracks of tiny scavengers buried within the trilobite carcass buried deep in the muddy bottom.

From the excavated tunnels, the scavengers targeted the soft tissue but consistently avoided the gut, which was unusual. They may have realized that the activity of digestive enzymes is still going on in the trilobite’s digestive system, so they are in mortal danger here.

However, they were also unlucky, as they soon became trapped in a solid “ball” around the dead trilobite, evidenced by the lack of escape tracks.