of D. attemsi implies the range of the species is moving north. Not only in Sweden are species of Lumbricidae expanding their range; many of the species found in Finland are exhibiting similar increases in range and Lumbricidae worms are also expanding into northeastern Europe, starting from the near Baltic Sea.

A 2022 molecular phylogenetic study of the highly diverse Franco-Iberian genus Zophoscolex showed most of the Iberian species to form a distinct clade, formally