|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.
|P. Y. Parkhaev and Y. Demidenko 2010||"Hollow, asymmetrical, pyramidal sclerites, straight or curved, narrowing towards distal end. Sclerites lack distinctly outlined base due to absence of any contraction at proximal end. Cross-section of sclerite irregularly trapezoid or irregularly polygonal, or rarely has irregularly triangular shape, transforming distally into triangular or trapezoid outlines. Distal end blind, rounded or pointed with narrow and often broken off tip. External ornamentation represented by longitudinal ribs and transverse rugae."|