The proportion of different platform types for flakes in contexts 1–3 (Layer A and the upper part of Layer B) and context 10a (the upper part of Layer E).

<p>The proportion of different platform types for flakes in contexts 1–3 (Layer A and the upper part of Layer B) and context 10a (the upper part of Layer E).</p

Four discoidal cores from Saffaqah.

<p>Note that the core on the bottom left has an unequal plane of intersection and would be classed as hierarchcial, but that its upper surface is still conical like the other discoidal cores.</p

A giant flake lying horizontally on the surface of context 2.

<p>A giant flake lying horizontally on the surface of context 2.</p

Boxplot of estimated core volume for selected Saffaqah localities, showing that localities associated with the dyke have the largest cores.

<p>Note that the very largest cores from 206–76 are too large to show at this scale.</p

Acheulean technology and landscape use at Dawadmi, central Arabia - Fig 17

<p><b>Handaxe (top), cleaver (middle), and early stage biface (bottom) from Saffaqah.</b> The handaxe and cleaver are made on large flakes, while the early stage biface is made on a cobble. The handaxe is from Saffaqah 177 and is 165 mm long. The cleaver is from Saffaqah 206–76 surface and is 144 mm long. The early stage biface is from Saffaqah 206–76 excavation context 10b (Layer E) and is 193mm long.</p

The vertical distribution of artefacts in the Whalen Trench by material, size, and density.

<p>Layers were drawn by the present authors and correspond to those in the 2014 excavation. Only the upper part of Layer F containing artefacts is shown. Note that the vertical scale is exaggerated.</p

Examples of discoidal cores from Saffaqah 206–76.

<p>Note that both surfaces are centripetally worked with scars terminating at peaks in the centre of the pieces.</p

The location of Dawadmi in central Arabia, showing other areas of Acheulean discoveries mentioned in the text.

<p>Basemap reprinted with permission from Esri, ArcGIS, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, Aex, Getmapping, Aerogrid, IGN, IGP swisstopo, and the GIS User Community under a CC-BY license, original copyright 2018.</p

The horizontal distribution of cores, flakes, and bifacial tools in the Whalen Trench divided by layers.

<p>The horizontal distribution of cores, flakes, and bifacial tools in the Whalen Trench divided by layers.</p

Plan of the Whalen et al. and Palaeodeserts trenches, showing Whalen’s three excavation units (S, T, and U) and the section of his excavation from which lithics were sampled for depth analysis in the present study.

<p>Plan of the Whalen et al. and Palaeodeserts trenches, showing Whalen’s three excavation units (S, T, and U) and the section of his excavation from which lithics were sampled for depth analysis in the present study.</p