The Circeo i cranium, discovered in Italy's Guattari Cave, has become a symbol of Neandertal spirituality and mortuary practice. Its discovery context and bony trauma are often attributed to Late Pleistocene ritual cannibalism. The cranium was introduced in I939, concluding that ritual cannibalism was practiced at Grotta Guattari. The skull shows two mutilations: one caused by violent blows on the right temporal region, suggesting a violent death, and the other by incising the periphery of the foramen magnum, creating a subcircular opening. Sergi at the University of Rome observed similar fractures on the Circeo i cranium and modern crania specimens, leading to the conclusion that the Circeo i specimen was the remnant of a cannibalistic Neandertal mortuary ritual. Blanc interpreted the basal intentional mutilation as identical to modern headhunters of Borneo and Melanesia. He appealed to contextual evidence, including the lack of associated hominid remains in the cave, the discovery of the cranium in a circle of stones, the upward orientation of the broken base, and the contrast between the stone-floored main cave chamber and the unpaved inner chamber. Blanc's conclusion regarding the Circeo i discovery represents one of the most established interpretations in paleoanthropology.

The Circeo i cranium, shows symmetrical enlargement of the foramen magnum. This pattern is similar to other hominid skulls and fossil hominid crania. The researchers examined the cranium in I986 for evidence of ancient hominid-induced damage. They studied cannibalized human remains from the American Southwest and a random sample from the University of Rome Melanesian cranial series. They found that the good architecture of the occipital was suitable for symmetrical fracture, suggesting human. 

The Circeo i cranium, a Neandertal skull, has been found to have a significant amount of cave coral, obscuring much of its lower facial skeleton. The cranium was found to be asymmetrically positioned on its left side, with most fractures being ancient. Recent damage to the specimen includes minor chippage to the right frontal and basicranium, breakage of the right temporal's zygomatic process, and vault exfoliation. Laboratory preparation damage in the form of drilling marks is evident on the occipital. All damage to the Circeo i Neandertal cranium was inflicted after fossilization, presumably during and after recovery. The damage pattern on the Circeo i specimen is similar only at the gross, superficial edge of basal breakage to the pattern observed by Blanc, Sergi, and others on the Circeo specimen. The study reveals damage to the zygomatic process of the right temporal, with pits and grooves indicating carnivore-induced damage. The damaged area has two large grooves and an irregular foramen magnum. The endocranial surface shows some ancient trauma, with a small pit marking the endocranial edge. A damaged patch extends along the ridge of the superior sagittal limb of the cruciate eminence, with deep gouges. The damaged area also comprises two major striae of io-mm length. The study also examines the Circeo 2 and 3 mandibles, revealing postfossilization preparation damage and striae caused by study instruments. The damage and surface alterations are consistent with carnivore manipulation of the fresh cranium. The Circeo i specimen from the Guattari deposit, demonstrates no polish, cut marks, or percussion-impact features, suggesting that it was not a hominid-made object. However, the Neandertal cranium does show ancient modifications consistent with camivore manipulation. The discovery of the Circeo i cranium has led to several hypotheses about prehistoric hominid activity on the surface of the deposit. However, the exact disposition of the cranium and its immediate associations were lost shortly after its discovery, and all subsequent arrangements are conjectural. The cranium's symmetry corresponds with anatomical symmetry and is not diagnostically hominid-made. The evidence for carnivore modification of the cranium is strong but not unequivocal. Actualistic investigations on striped hyaena modification of modern human crania may provide further insight into carnivore modifications to hominid skeletal remains.