Findings in title quoted from the linked paper^1 in Nature Ecology & Evolution and an Italian-language summary^2 by ANSA news agency.

From the linked paper:^1

>Pleistocene archaeology records the changing behaviour and capacities of early hominins.

>These behavioural changes, for example, to stone tools, are commonly linked to environmental constraints.

>Simbiro III level C, in the upper Awash valley of Ethiopia, allows us to test this assumption in its assemblage of [575] stone tools made only with obsidian, dated to more than 1.2 million years (Myr) old.

>Following the deposition of an accumulation of obsidian cobbles by a meandering river, hominins began to exploit these in new ways, producing large tools with sharp cutting edges.

>We show through statistical analysis that this was a focused activity, that very standardized handaxes were produced and that this was a stone-tool workshop.

>We argue that at Simbiro III, hominins were doing much more than simply reacting to environmental changes; they were taking advantage of new opportunities, and developing new techniques and new skills according to them.

>[The 575 of 578] standardized obsidian handaxes provide ample evidence of the repetitive use of fully mastered skills.

>[The early hominins] creatively solved through convergent thinking technological problems such as effectively detaching and shaping large flakes of the unusually brittle and cutting volcanic glass.

^1 Mussi M., et al. A surge in obsidian exploitation more than 1.2 million years ago at Simbiro III (Melka Kunture, Upper Awash, Ethiopia). Nature Ecology & Evolution (2023). https://doi.org/10.1038/s41559-022-01970-1

^2 Officina artigianale di 1,2 mln di anni fa scoperta in Etiopia, 20 Jan. 2023, https://www.ansa.it/sardegna/notizie/2023/01/20/officina-artigianale-di-12-mln-di-anni-fa-scoperta-in-etiopia_9c0dda4f-c7f8-4fd4-9cbd-3fbce9af0a20.html