|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.
|J. Sprinkle 1973||Calyx conical to club-shaped, composed of numerous thick adjacent plates showing fairly good pentameral symmetry and bearing circular or slightly elliptical epispires on their margins. Single very thick basal plate at based of calyx. Domed oral surface consists of central mouth, lateral anal pyramid, and 5 relatively short ambulacra with single plates bearing long biserial brachioles. Long, slowly tapering stem with 1-piece columnals attached to base of calyx. Early Ordovician (Upper Tremadocian), Morocco.|