A remarkable discovery at a Roman archaeological site in northwestern Spain is offering new insights into the aesthetic tastes, spiritual beliefs and long-distance trade practices of the ancient Romans. At the settlement of A Cibdá de Armea, archaeologists unearthed a 450-million-year-old trilobite fossil — an extinct marine arthropod — that appears to have been intentionally modified for use as jewelry between the 1st and 3rd centuries CE.
This find is historic on several fronts: It is the first confirmed instance of a trilobite fossil used as personal adornment in the Roman world and only the third known example of such usage by any ancient human population. Measuring just under 4 centimeters (about 1.5 inches), the fossil shows seven artificial wear facets on its underside — flattened areas likely created to help the piece lie flush when mounted in a bracelet or pendant. Researchers believe it may have been encased in gold, silver or leather.
Its striking reddish hue, caused by mineralization in iron oxide, helped researchers trace its origin to the Tristani Beds in the southern Central Iberian Zone, which is about 430 kilometers (267 miles) from the site. That such a small item was transported over such a vast distance suggests it held considerable value, not just as an ornament but as a symbol imbued with magical or protective powers.
According to the study, which was published in Archaeological and Anthropological Sciences, the fossil was discovered alongside a bronze coin of Emperor Augustus, Rome’s first emperor, who ruled from 27 BCE to 14 CE. Roman historian Suetonius wrote that Augustus was fascinated by fossils. The emperor reportedly excavated them personally on the island of Capri and exhibited them in what may have been the ancient world’s first paleontological museum at his villa. His collection included what he believed were the bones of giants and mythical creatures — likely the fossils we now recognize as prehistoric remains.
The Armea trilobite offers a rare look at how the ancient Romans incorporated prehistoric objects into daily life and spiritual practice. Fossils in Roman culture were not merely geological curiosities; they were seen as talismans from a primordial world, with the power to protect or bring luck to their owners. The segmented form of the trilobite may even have inspired Roman jewelry designs in jet or black glass known as Trilobitenperlen.
Credits: Jewelry illustration courtesy of A. Fernández-Fernández et al., Archaeol Anthropol Sci (2025). AI-generated image of ancient Romans wearing trilobite jewelry by The Jeweler Blog using ChatGPT and DALL-E 3. Trilobite illustration by Віщун, CC BY-SA 4.0, via Wikimedia Commons.
