The numismatic evidence anchors the ritual activity firmly in time. The numerous coins recovered from the deposits range in date from the early second century AD to the late fourth century AD, with a clear peak in minting during the second half of the fourth century. That concentration matters, because it suggests the sanctuary flourished precisely during Late Antiquity, an era when traditional Roman religion was increasingly under pressure from Christianity and older cults were retreating into discreet, secluded spaces. A mine gallery, accessible only through a controlled entrance and plunged into permanent darkness, would have suited the Mithraic liturgy well. Mithraea across the Roman world were typically small, cave-like rooms without windows, and scholars have long noted that the cult’s reverence for the cave in which Mithras slew the bull made subterranean spaces especially attractive. Yet the Kropfsberg site holds a caveat: no direct depiction of Mithras, whether an altar, inscription, or metal plate, has so far come to light.

To test the ritual hypothesis, researchers turned to the animal bones. In total, 486 animal bones and teeth were recovered by hand from the Late Antiquity layers, of which 295 remains, weighing nearly 567 grams, could be identified to species. The analysis was carried out at the Natural History Museum Vienna, in its First Zoological Department and Archaeological-Zoological Collection, using the standard quantification methods of archaeozoology: the number of identified specimens, or NISP, and the weight of the material, the latter helping to estimate which species contributed most meat. The state of preservation was remarkably good, so good that fragile bones from birds and very young animals survived in high numbers, a fact that immediately hinted the assemblage was not an ordinary domestic refuse pile.

The species profile is dominated by domesticated animals, and the pattern is unusual. By fragment count, pig remains prevail at 47.5 percent of identified specimens, followed by chicken at 38.6 percent, sheep and goat at 12.9 percent, and cattle at a mere 1 percent. The weight analysis shifts the picture slightly, because heavier bones carry more mass: pigs still dominate at 50.5 percent, but sheep and goat follow at 20.7 percent, cattle at 15 percent, and chicken at 13.8 percent, indicating that after pigs the small ruminants were the most important meat suppliers at the site. Compare this with contemporary Late Antiquity settlements in northeastern Austria, such as Oberleiserberg, Drösing, Michelstetten, Zwingendorf, Potzneusiedl, and Podersdorf, where cattle typically make up 38 to 45 percent of identified remains and chicken rarely exceeds 5 percent. The Kropfsberg percentages fall entirely outside those ranges.

The age and sex structure of the animals sharpens the contrast further. Epiphyseal fusion of the bones shows that the overwhelming majority of pigs and sheep or goats were non-adult. Nearly 88 percent of the pig remains came from animals younger than two and a half to three years, with almost a third of them younger than one year. Tooth analysis confirmed the pattern: four of the five pig teeth recovered were milk fourth premolars from animals younger than six months, and the single permanent third molar belonged to an animal of roughly eighteen to twenty months. Sheep and goats tell the same story, with almost 89 percent of remains from individuals younger than three years and a third younger than one year. In ordinary settlements, animals were kept to adulthood because cattle, sheep, and goats had economic value beyond meat, in traction, wool, and milk. Slaughtering animals young is economically wasteful, unless the goal is a table of tender, succulent meat for a very specific occasion.

The chickens add a final, telling detail. Sex could not be determined for the mammals because too few adult bones were present, but the chicken bones could be sexed metrically. Comparing the Kropfsberg measurements, such as the greatest lengths of the coracoid, humerus, radius, ulna, carpometacarpus, and femur, with the large reference assemblage from the Avar-period cemetery of Vienna Csokorgasse, the researchers found that the values fall within the range of variation of male individuals. A dominance of male chickens, combined with the slaughter of juvenile pigs and sheep, matches precisely the faunal signature documented at Mithraea elsewhere in Europe, from older studies such as the classic mid-twentieth-century excavations to recent analyses of sanctuaries in Germany, Switzerland, Belgium, and France. Similar profiles have also been reported from the cult cave of Zillis in the Swiss canton of Graubünden, itself interpreted as a Mithraic site, and from sanctuaries of other deities, including the sanctuary of Jupiter Heliopolitanus at Carnuntum and the Apollo-Grannus sanctuary at Neuenstadt am Kocher, where chickens likewise play an outsized ritual role.

The bones also preserve the physical evidence of butchery and consumption. Chop marks far outnumber cut marks across all species. Pig crania were split in two, with additional chops removing the incisive bone, frontal bone, and maxillae, and severing the skull from the neck at the occipital condyles. Long bones were chopped diagonally at the joints, and one femur shows longitudinal blows for marrow extraction. Ribs were reduced to small portions, vertebrae were split mediansagittally or parasagittally, and sheep and goat carcasses were dismembered in comparable fashion, with cut marks above the teeth on the maxillae indicating careful separation of the head. Even the chicken bones carry oblique and transverse chops and cuts on the femur, tibiotarsus, furcula, coracoid, and radius. These marks demonstrate that the remains are food waste from meals eaten on site, while gnawing marks from scavengers show that at least some refuse lay exposed on the ground, or only partially buried, for a time. One pig rib bears new bone formation consistent with periostitis, the single pathological specimen in the assemblage.

Fire and sediment tell an even more intricate story. About 20 percent of the identified material, and many of the unidentified bones, show the black coloration characteristic of exposure to temperatures between roughly 300 and 600 degrees Celsius. Burning of animal remains is documented in numerous ritual practices across antiquity, including within the Mithras cult itself. Meanwhile, micromorphological analysis of soil thin sections revealed tiny bone splinters embedded in the matrix, mixed with charcoal and clods of sediment in a pit-like floor depression. A comparable phenomenon was first described at the Mithraea of Biesheim and Kempraten, where bone splinters embedded in floor layers were interpreted as evidence of multi-stage ritual activity. At Kropfsberg the splinters were not part of a renovated floor but were deposited in a deliberate depression, again suggesting ceremonies that unfolded in several phases, involving feasting, burning, and the working of bone fragments into the ground.

The teeth even offer a calendar. Age at death reconstructed from tooth eruption and wear, principally the milk fourth premolar and the unworn third molar of pigs, points to slaughtering around the summer season, though the researchers caution that the sample is small and the eruption timing of third molars in ancient pig populations may have been closer to that of wild boar, around 23 to 26 months, than to modern domestic pigs. Taken together, the evidence sketches a vivid scene: somewhere in the late fourth century, in the darkness of an old copper mine in the Alps, a small community slaughtered young pigs, sheep, and roosters, cooked and ate them in ritual meals, burned a fifth of the bones, and left the debris in a sealed underground chamber. Whether the Kropfsberg sanctuary ultimately belonged to Mithras cannot be proven without an image or inscription, and the authors acknowledge that comparable faunal profiles occur in other religious contexts. But the enclosed and lockable setting, the bench-like substructure, the votive sheets, the coins, and now an animal assemblage that mirrors known Mithraea north and south of the Alps make the Tyrolean mine one of the most intriguing new windows onto the secret religions of Rome’s fading frontier.

Subject of Research: Archaeozoological analysis of faunal remains from a possible Late Antique Mithraic sanctuary in an Austrian copper mine

Article Title: Faunal remains from the Late Antiquity ‘cave sanctuary’ (Mithraeum?) of Kropfsberg (Tyrol, Austria)

Article References: Faunal remains from the Late Antiquity ‘cave sanctuary’ (Mithraeum?) of Kropfsberg (Tyrol, Austria). (n.d.). https://doi.org/10.3897/anhmw.187321

Image Credits: AI Generated

DOI: 10.3897/anhmw.187321

Keywords: archaeozoology, Mithraism, Late Antiquity, Kropfsberg, Tyrol, Roman religion, faunal remains, ritual feasting, copper mining, chickens, pigs, Natural History Museum Vienna