The paper has an exciting conclusion, at least to this non-expert: "Here, we show that rock types similar to those found at Oldowan archaeological sites can be

The paper has an exciting conclusion, at least to this non-expert: "Here, we show that rock types similar to those found at Oldowan archaeological sites can be distinguished by chimpanzees (Plummer, 2004; Braun et al., 2008, 2009b; Plummer et al., 2023). The patterns of selection by the chimpanzees at Bossou show levels of selectivity that are similar to those identified in the earliest hominin toolmakers (Fig. 10). In fact, selection for pounding tools in the Oldowan archaeological record (Lokalalei 2C) shows lower levels of selectivity than that seen in chimpanzees (although the reasons for selection may be governed by different activities that hominins at Lokalalei 2C were engaged in)." https://www.sciencedirect.com/science/article/pii/S0047248424001337 https://www.sciencedirect.com/science/article/pii/S004724842...