Comment on 'Early Homo erectus lived at high altitudes and produced both Oldowan and Acheulean tools' by Mussi et al. (2023)

Comment on ‘Early Homo erectus lived at high altitudes and produced both Oldowan and Acheulean tools’ by Mussi et al. (2023) ROSALIA GALLOTTI • Researcher • LabEx ARCHIMEDE and UMR 5140 Archéologie des sociétés méditerranéennes, Université Paul Valéry Montpellier 3 – CNRS, Campus Saint Charles, 34199 Montpellier and Université Bordeaux, CNRS, UMR 5199 PACEA-PPP, Bâtiment B18 Allée Geoffroy Saint-Hilaire CS 50023, 33615 Pessac Cedex, France GIOVANNI MUTTONI • Professor • Dipartimento di Scienze della Terra ‘Ardito Desio’, Università degli Studi di Milano, via Luigi Mangiagalli 34, 20133 Milan, Italy SERENA PERINI • PhD student • Dipartimento di Scienze della Terra ‘Ardito Desio’, Università degli Studi di Milano, via Luigi Mangiagalli 34, 20133 Milan, Italy JEAN-PAUL RAYNAL • Directeur de recherche émérite • CNRS, France Abstract Mussi et al. (2023) claim that Homo erectus produced both Oldowan and Acheulean tools at Melka Kunture. Melka Kunture is one of the key East African sites to investigate the Oldowan/Acheulean transition and its toolmaker(s), resting on a solid chronostratigraphy and in depth lithic analyses previously published. We asses that Mussi et al. (2023) contains i) an incorrect reinterpretation of the stratigraphy and magnetostratigraphy at the Garba locality and ii) no robust data to verify the previously published hypothesis that Homo erectus was the only toolmaker at the Oldowan/Acheulean transition. Comment Mussi et al. (1) report new analyses on a child mandible discovered in 1981 in the late Oldowan Garba IVE site at Melka Kunture (Ethiopia), confirming its identification as Homo erectus. These results are particularly welcome because of the scarcity of hominin remains co-occurring with industries in well controlled and dated contexts (1). Mussi et al. (1) also assessed that “Homo erectus produced both Oldowan and Acheulean tools”. We contend that this hypothesis was published earlier (2,3; not cited in Mussi et al. (1)) and it remains speculative in absence of hominin fossils from the early Acheulean Garba IVD site and the difficulty to categorically attribute the humerus from the early Acheulean Gombore IB site to Homo erectus (4,5), whose dating (~1.66 Ma) should be taken with caution (6). Previous papers indicate that at Garba IV the Oldowan/Acheulean transition represents a continuous techno-economic process (2,3) as revealed by the study of a large corpus of artefacts (7,8) retrieved in a high-resolution chronostratigraphy (6,9,10). We also contend that the original chronostratigraphy of the Melka Kunture sequence of Perini et al. (6), on which Mussi et al. (1) based their inferences, has been incorrectly reported in Mussi et al. (1). Perini et al. (6) assessed the chronostratigraphy of the Melka Kunture sequence, including Garba IV, by integrating magnetostratigraphic data from nine individual sections with previously published 40Ar/39Ar ages (11). Furthermore, two additional sections have been studied for a better definition of the critical Olduvai subchron at the base of the sequence (9). In their review of the ‘geochronological context of the Garba deposits’ based on ‘direct surveys made in 2013 and 2017’, Mussi et al. (1) introduced however what seems to be a reinterpretation of some critical aspects of the original chronostratigraphy of Perini et al. (6). Notably, in Mussi et al. (1) archaeological level F at Garba IV is correlated to the Reunion subchron at ~2.1 Ma (see their Fig.1C-D), but in the original chronostratigraphy (6) level F was reported ~80 cm above and not correlative to a short normal polarity interval interpreted as a possible record of the Reunion subchron (6) (for differences between Mussi et al. (1) and Perini et al. (6) see Figure 1 of this comment https://drive.google.com/file/d/1zKHpocne8HAPlxjZkaJfQKRiKik5qh0x/view?usp =sharing). This new and forced interpretation, which makes level F more than 100 kyr older than originally calculated (6), does not seem imputable to field observations produced after Perini et al. (6), as Garba IV was sampled for magnetostratigraphy by GM in 2017, at the time of the ‘direct surveys’ cited by Mussi et al. (1). Another element of discrepancy is the vertical distance between archeological levels F and E in Mussi et al. (1) that is 60 cm in their Fig.S11 and 140 cm in their Fig.1. We also stress discrepancies in the order of tens of cm in the stratigraphic positions of paleomagnetic samples in Mussi et al. (1) relative to Perini et al. (6) (see Figure 1 of this comment). An additional element of criticism is that the composite stratigraphy of Mussi et al. (1), valid for the Garba gully (see their Fig.1B), reports magnetic polarity reversals, such as the base and top Jaramillo and the Brunhes/Matuyama boundary, that were retrieved (6) from entirely different sections (Garba III and Garba XII) located ~100 m to the Est of the Garba gully (see Figure 1 of this comment). Such oversimplified piecing together of data from different sections gives the false impression of a stratigraphic continuity that does not exist. We therefore suggest to refer to Perini et al. and Muttoni et al. (6,9) for a realistic description and representation of the (complex) chronostratigraphy at Melka Kunture. Acknowledgements We thank the Authority for Research and Conservation of Cultural Heritage (ARCCH, currently Ethiopian Heritage Authority) of the Ministry of Culture and Tourism (currently Ministry of Tourism) for fieldwork permits given to the French Archaeological Mission at Melka Kunture and to the Italian Archaeological Mission at Melka Kunture and Balchit which excavated Garba IV site in 1973-1982 under the direction of J. Chavaillon and the supervision of M. Piperno and in 2005, 2008, and 2009 under the direction of M. Piperno and the supervision of R. Gallotti. Author contributions All authors were involved in discussion and wrote the manuscript. G.M. and S.P. made magnetostratigraphy. R.G. supervised Garba IVD, E, and F excavation in 2005, 2008, and 2009 and analysed Garba IV lithic collections. J.-P.R. made stratigraphical analyses. References 1. Mussi et al., Science 382, 713–718 (2023). 2. Gallotti, M. Mussi, Journal of Anthropological Sciences 95, 137-181 (2017). 3. Gallotti, M. Mussi, in The Emergence of the Acheulean in East Africa and Beyond. Contributions in Honor of Jean Chavaillon. R. Gallotti, M. Mussi, Eds. (Springer, Cham, 2018), pp. 53-92. 4. Di Vincenzo et al., Quat. Sci. Rev. 122, 207–221 (2015). 5. Cazenave et al., Comptes Rendus Palevol, 16, Issues 5–6, 521-532 (2017). 6. Perini, G. Muttoni, E. Monesi, R.T. Melis, M. Mussi, Quat. Sci. Rev. 274, 107259 (2021). 7. Gallotti, J. Hum. Evol. 65, 594–620 (2013). 8. Gallotti, M. Mussi, PLOS ONE 10, e0145101 (2015). 9. Muttoni, S. Perini, R.T. Melis, M. Mussi, Quat. Sci. Rev. 319, 108330 (2023). 10. -P. Raynal, G. Kieffer, G. Bardin, in Studies on the Early Paleolithic Site of Melka Kunture, Ethiopia, J. Chavaillon, M. Piperno, Eds. (Istituto Italiano di Preistoria e Protostoria, Roma, 2004), pp. 137–166. 11. E. Morgan et al., J. Hum. Evol. 62, 104–115 (2012).