Abundance ratios for the α elements Mg, Ca, and Ti (from top to bottom) as a function of [Fe/H]. Sextans stars are large red symbols. The new EMP stars studied in this paper are the red circles. The sample of Aoki et al. (2009) that we reanalyzed is shown as red triangles. Data from Shetrone et al. (2001b) are upside-down triangles. Gray dots are literature data for MW halo stars (Venn et al. 2004; Cohen et al. 2013; Yong et al. 2013; Ishigaki et al. 2013). Orange and blue symbols refer to RGB stars observed in Sculptor (Jablonka et al. 2015; Tafelmeyer et al. 2010; Starkenburg et al. 2013; Simon et al. 2015) and Fornax (Tafelmeyer et al. 2010), respectively.