1. Soil units of the Arenosol reference group are linked with Cryosols (Gelic Arenosols), Solonchaks (Hyposalic Arenosols), Gleysols (Gleyic Arenosols), Andosols (Tephric Arenosols), Podzols (Albic or Hyperalbic Arenosols),Plinthosols ( Plinthic Arenosols),Ferralsols ( Hypoferralic Arenosols),

2. In Cladistics or phylogenetics, an outgroup is a more distantly related group of organisms that serves as a reference group when determining the evolutionary relationships of the ingroup, the set of organisms under study, and is distinct from sociological outgroups.The outgroup is used as a point of comparison for the ingroup and specifically allows for the phylogeny to be rooted.