Both species are rare in the field and are fairly elusive, thus phylogenetic affinities of fairy armadillos have been tested only once. As a result of the research conducted in 2009, the idea of respective monophyly of the 3 previously identified subfamilies Dasypodinae, Euphractinae, and Tolypeutinae (which separated from each other shortly after the Eocene-Oligocene transition) was supported. The Chlamyphorinae subfamily was found to show phylogenetic affinities with the clade Tolypeutinae, which became a significant step to define the previously completely unknown phylogenetic position of this armadillo subfamily within Cingulata. Later, the separation of the fairy armadillo subfamily from their tolypeutine sister-group was estimated to have occurred 32 ± 3 Mya.