|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|C. G. Barras 2007||Stem group Atelostomata with a clearly disjunct apical disc containing a small number of complemental plates (Fig. 2C). The complemental plates preclude the direct contact of oculars II and IV. The periproct lies at the posterior of the test in a slight depression, the remnant of a periproctal groove (Pl. 2, fig. 1c). The genus retains the primitive short phyllodes (Fig. 10G) and the peristome lies in a slight depression (Pl. 2, fig. 1b).|