“…In the case of SV, the cultivation of millet, although possible only during spring–summer, resulted in a strong C 4 signal in this population (Laffranchi, 2016; Laffranchi et al, 2016). The cultivation of millet in the Po plain is documented since the Bronze Age (Tafuri et al, 2009; Tafuri et al, 2018; Varalli et al, 2016) and continued to be practiced during Late Antiquity and early Middle Ages (Ganzarolli et al, 2018; Laffranchi, Mazzucchi, et al, 2020; Marinato, 2016, 2017, 2019; Maxwell, 2019). In contrast, the low minimum temperatures characterizing mountain areas make the latter incompatible with the cultivation of C 4 plants (Teeri & Stowe, 1976).…”