|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Rhynchonellata - Orthida - Orthidiellidae
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.
|O. I. Nikitina et al. 2006||Shell ventribiconvex; anterior commissure gently sulcate; radial ornament costellate. Ventral interarea apsacline, deltidium narrow, arched, imperforate. Dorsal interarea short, anacline; notothyrium open or closed partly by chilidial plates. Ventral interior with a shallow delthyrial cavity, occupied by small undifferentiated muscle field; teeth short, stout, supported by low, slightly divergent dental plates; mantle canals saccate, vascula media straight, slightly divergent. Dorsal interior with a broad, poorly defined notothyrial cavity that bears a short, blade-like cardinal process posteriorly; brachiophores short with stout bases; adductor muscle scars are paired elongate oval depressions separated by a broad median ridge; dorsal mantle canals digitate.|