The pothole in the Filo Quarry, which came to light by chance during quarrying at the end of the 1950s consisted of a shaft, initially 11 m deep, which proceeded to the north-west in a small cavern. The deposit filling the cavern was excavated in 1966 by the Italian Institute of Speleology. It comprised three main formations separated by marked stratigraphic inconsistencies. The fill contained an important assemblage of faunal remains (over 10 species) relating to the final phases of the Wűrm period (Pasini 1968). The complete demolition of the upper part of the deposit by the quarrying activity and several contradictions in the interpretation of the data from the first excavations have prevented the establishment of a chronology for the deposit, which in the light of present and still provisional knowledge correlates to isotopic stages 3 and 2. The new research, whose main objective was to document the remaining lower stratigraphic levels, uncovered two distinct strata of clay silt (U.S. 99/U.S. 100) in the NE cavity of the impluvium which contained fossils relating to small rodents and large mammals.
The new investigations recovered 49 new fossils and identified the remains of wolf, Canis lupus, bison of the steppe, Bison priscus and megaceros, Megaloceros giganteus and gathered taphonomic and geological data. (MiBAC)