Trilobite Fossil Found in a Roman Imperial Site

The collection of fossils by humans has a very long history. Archaeological evidence shows that even at Paleolithic sites, fossils were sometimes deliberately gathered and concentrated in specific locations. However, trilobite fossils are extremely rare in archaeological contexts. Prior to this discovery, only a small number had been reported from sites in Western Europe, North America, South Africa, and Australia. A recent study describes a trilobite fossil recovered from a Roman imperial site in northwestern Spain. This specimen represents the eleventh trilobite fossil ever documented from an archaeological context, the first known example from a Roman imperial site, and only the third trilobite fossil known to have been collected, used, and preserved by humans for more than a thousand years.

Roman archaeological site where the trilobite was discovered（圖片來源：Fernández-Fernández, A et al. (2025). ，採用 CC BY 4.0 授權。）

According to the Roman historian Suetonius, the first Roman emperor, Octavian (Augustus), possessed a strong interest in fossils. He reportedly imported fossil specimens from Greece and organized excavations on the island of Capri. Augustus even constructed what is regarded as the first recorded paleontological museum within his villa, where bones believed to belong to giants and monsters were displayed. His successor, Emperor Tiberius, shared a similar enthusiasm. Following an earthquake in Anatolia, he dispatched an official delegation to the region to collect numerous fossils. Most fossils mentioned in historical accounts, however, consist of bones and teeth from large vertebrates. Although a few written sources refer to fossils of smaller invertebrates, such remains are almost absent from archaeological sites. As a result, our understanding of the relationship between Roman society and small invertebrate fossils remains extremely limited.

The trilobite fossil described in this study represents the first recorded trilobite specimen within the Roman world. Its surface bears clear traces of deliberate human modification, giving the object significant archaeological importance.

Trilobite specimen; b shows its appearance in life（圖片來源：Fernández-Fernández, A et al. (2025). ，採用 CC BY 4.0 授權。）

After analysis and taxonomic identification, the fossil was determined to belong to an undetermined species of the genus Colpocoryphe, catalogued as specimen CCA21-3965. Based on current paleontological knowledge, species of Colpocoryphe and related genera were primarily distributed across southwestern Europe, central Europe, North Africa, and western Asia, a geographic range that overlaps with the location of the archaeological site where the fossil was discovered. The preserved portion corresponds to the middle and posterior regions of the trilobite. Although the specimen might represent the remains of a trilobite body, the posture and preservation suggest that it more likely represents a molted exoskeleton left behind after the animal underwent periodic molting.

Geochemical and lithological analysis indicates that the fossil originated from Middle Ordovician shale outcrops located somewhere in the central-southern Iberian Peninsula. This source area lies at least 430 kilometers from the Roman site where the specimen was recovered, strongly indicating that the fossil was intentionally transported there. Archaeological dating of the site places its occupation between the first and second centuries CE. At the time of excavation, the area where the specimen was found appears to have been used as a refuse deposit.

Location within the site where the trilobite specimen was found（圖片來源：Fernández-Fernández, A et al. (2025). ，採用 CC BY 4.0 授權。）

The overall shape of the fossil is approximately circular. Most of the preserved exoskeleton retains its natural form, but the underside and sides of the specimen show as many as seven areas of abrasion. These modifications appear to have been intentionally produced, both to flatten the base and to give the fossil a more rounded overall shape.

Abrasion surfaces on different parts of the trilobite specimen（圖片來源：Fernández-Fernández, A et al. (2025). ，採用 CC BY 4.0 授權。）

The rarity of trilobite fossils and other Paleozoic organisms in archaeological sites is largely due to geological factors. Paleozoic fossils are typically embedded within relatively hard rock layers, which resist weathering and erosion. Consequently, such fossils rarely become naturally exposed at the surface. When Paleozoic fossils do appear in archaeological contexts, they are usually discovered accidentally during quarrying or stone extraction for construction materials.

Historical sources suggest that Roman scholars possessed a certain understanding of small invertebrate fossils. They recognized them as remains of ancient organisms and sometimes interpreted them as evidence that the land had once been covered by prehistoric seas. Because of their rarity, such fossils were often believed to possess magical or protective properties at their places of origin. In some cases, they were used in religious settings as offerings or votive objects.

The specimen described in this study was clearly modified by human hands, indicating that the person who shaped it intended it for a particular purpose. Several possibilities have been proposed. The fossil may have served as a gaming piece in a board game. It might also have been incorporated into a leather bracelet or mounted within a metal frame to form a pendant. Regardless of its precise function, it was likely regarded as a special object possessing protective or magical qualities.

Reconstruction showing the trilobite specimen possibly made into a leather bracelet or pendant（圖片來源：Fernández-Fernández, A et al. (2025). ，採用 CC BY 4.0 授權。）

It is also possible that some Romans simply collected fossils as curiosities or specimens. Numerous artifacts resembling trilobites have been found at archaeological sites. These objects are made from materials such as black glass or jet and are commonly referred to as “trilobite beads” (Trilobitenperlen). Unfortunately, the absence of fossil examples in many contexts has made it difficult to determine whether these beads were directly modeled after trilobite fossils.

The trilobite fossil described in this study may help clarify this question. Its morphology closely resembles that of trilobite beads, suggesting that craftsmen may have imitated the segmented thoracic structure of trilobites when producing these ornaments. In this way, inexpensive replicas could have replaced genuine trilobite fossils, which were both rare and difficult to obtain.

Comparison between the trilobite specimen and trilobite beads（圖片來源：Fernández-Fernández, A et al. (2025). ，採用 CC BY 4.0 授權。）

Based on the archaeological context, the fossil likely belonged to a prominent local family. It may have been placed on a household shrine or carried by a member of the family. Such amulets were often worn by women or children as protection against illness or malevolent forces, a practice supported by iconographic evidence and funerary traditions from the Roman period.

This discovery demonstrates that Roman people not only recognized fossils as remains of ancient organisms buried within the earth, but also attributed sacred and protective meanings to them. Because trilobite-bearing geological formations do not occur in the immediate vicinity of the site, the find also suggests the existence of long-distance fossil circulation networks within the Iberian Peninsula, possibly connected to mineral transport routes. The distinctive appearance of trilobites may have further inspired the design of protective ornaments, such as trilobite beads, which eventually became integrated into Roman material culture.

（Author: Bai Leng）

Reference:

Fernández-Fernández, A., Valle-Abad, P., Rodríguez -Nóvoa, A.A., García-Ávila, M., Romero, S., Gutiérrez-Marco, J. C. (2025). Significance of fossils in Roman times: the first trilobite find in an early Empire context. Archaeological and Anthropological Sciences.