There is some debate where the finfoot family, Heliornithidae, fits within Gruiformes. The Sibley–Ahlquist taxonomy of birds, based on DNA-DNA Hybridization, suggested that they are sister taxa to limpkins, the Aramidae, and even placed the limpkins within Heliornithidae in 1990. However, more recent genetic analyses suggests that limpkins are sister taxa to cranes, the Gruidae, and that finfeet are instead sister taxa to rails, the Rallidae. Other studies suggest that finfeet and the Afro-Madagascan flufftails, a group originally thought to be nested within rails, form a lineage called Sarothruridae that separated from each other at the end of the Eocene, probably in Africa. Sarothruridae, in turn, is considered a sister clade to Rallidae.