|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Rhynchonellata - Pentamerida - Clorindidae
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.
|C. M. O. Rasmussen et al. 2010||Small-sized, equi-biconvex to slightly ventri- biconvex with triangular to sub-pentagonal outline and moderately globose convexity in adult specimens. Widest point from mid-valve to anterior one-third of valve. Ventral valve arched with umbo usually protruding posterior of hingeline with an initially low and obscure sulcus that may become very pronounced at anterior commissure. Ventral interarea relatively high, narrow and curved. Dorsal valve less convex, usually with a sharply defined fold in adult specimens, but fold may also be low and obscure, nearly rectimarginate in juvenile specimens. Distinctive growth lamilae seen towards the anterior margin. Ventral interior with short deep and narrow spondylium supported by an even shorter median septum. Dorsal interior with sub-parallel, anteriorly abbreviated inner plates supporting equally short, but very thick, divergent outer plates. Carinae may be developed as bases of brachial processes, though these also could be hook structures.|