|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
Obolellata - Naukatida
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.
|M. Streng et al. 2016||Shell biconvex and astrophic, externally smooth or with radial ornament; ventral interarea with concave pseudodeltidium, symphytium or deltidium, which may be perforated apically by foramen; ventral interior with variably developed visceral platform and/or anteris forming spoon- or tube-like structures (modified after Popov et al. 1997).|