|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||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.
|W. Hantzschel 1975||Spirally coiled structures with circular outline; diameter 2 to 3 cm; surface covered by streaks either running parallel to periphery of circular outline or arranged in subspiral fanlike manner; streaks sometimes transversely annulated.|