How the Median Occipital Fossa Became Aymara

Cesare Lombroso’s famous account of “how criminal anthropology was born” positions the discovery of the anomalous median occipital fossa as the cornerstone of his theoretical elaboration on the born criminal and its atavistic nature. This final retelling, which followed several earlier versions, was published a few years after the scientist’s death in 1909. While the founding event acquired a mythic quality, Lombroso never questioned the scientific value of the “discovery.” His attempt to prove that the fossa was indeed a result of atavism became an obsession, beginning with his initial writing on the subject, “Existence of a median occipital fossa in the skull of a delinquent” from January 12, 1871. In this chapter, I aim to trace the most significant stages of the ensuing debate surrounding the atavistic interpretation of this anatomical feature. The literature produced was vast and highly specialized, and the timeframe considered here spans the most intense phases of the controversy over its significance, from 1871 to 1876 in Italy, and from 1883 to 1895 internationally. The primary goal of my reconstruction is to clarify Lombroso’s theoretical and methodological design, which culminated in his decision to name the median occipital fossa typology—found in the skull of Calabrian “brigand” Giuseppe Villella—after a South American people, the Aymara.