IoM space of the local halo sample described in Sect. 2.1 with ellipsoids showing over-density definitions of Thamnos from running a clustering algorithm (Lövdal et al. 2022) on various samples. The Gaia RVS sample definition used in this work is shown by a red ellipsoid. Other selections include extending the RVS sample (addition of ground-based RVs before clustering instead of adding them to the pre-defined clusters), a blue halo selection (those that are left of the isochrone separating the two sequences shown in e.g. Fig. 4), and complete samples (taking the M_G at the level that all stars down to that magnitude, in that volume, have a g_RVS above the RVS limit). The definitions by Ruiz-Lara et al. (2022b) of Thamnos 1 and 2 are shown as black and cyan ellipsoids here (see R-L+2022 in the legend). Black points show the individual clusters in the Thamnos region when clustering on a 1 kpc halo sample, highlighting the sub-structure we observe. The bottom panel shows the LAMOST DR7 LRS metallicity distributions for selecting from our 6D halo sample (Sect. 2.1) according to the different ellipsoids. These are normalised so that the area of each is equal to 1 and binned each with a relative shift of 0.01 dex to aid the comparison.