|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
Rhombifera - Pleurocystitidae
It was assigned to Pleurocystitidae by Sprinkle (1974); to Rhombifera by Sepkoski (2002); and to Deltacystinae by Sumrall and Sprinkle (1995) and Nardin and Bohatý (2013).
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 1974||Flattened pleurocystitid cystoids having a rounded triangular shape and a nearly symmetrical profile. Plating arrange- ment nearly symmetrical but abnormal for this family; BB, ILL, and LL circlets well devel- oped, closed (?), and present on both calyx sur- faces, RR and 00 circlets greatly reduced in size. Periproct small, occupying only 10-20%1 of the ventral side and containing relatively few, medium-sized periproctals. No pectini- rhombs present externally, although traces of slits have been observed internally on L4? and perhaps B2?. Two long biserial brachioles attached to summit beside central mouth, with brachiolar food groove running along inside dorsal surface. Proximal stem enlarged with smooth columnals; distal stem bears elongate flanged and smooth columnals|