Fig. 2.

Characterization of ancient and modern millet seeds. a Top row unearthed foxtail millet seeds; second row de-embryonated foxtail millet seeds; third row unearthed broomcorn millet seeds; fourth row de-embryonated broomcorn millet seeds. Scale bar 2 mm. b Illustration for measurement of millet seeds. θ angle of embryo notch; w ₁ width of the opening of the embryo notch; w _t width of the seed at the longest side; d ₁ depth of embryo notch; d _t depth of the seed at the longest side