|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
It was reranked as the class Osteostraci by Gadow (1898); it was reranked as the order Osteostraci by Hay (1902) and Dineley and Metcalf (1999); it was synonymized subjectively with Cephalaspidiformes by Long (2011).
It was assigned to Hypostomata by Gadow (1898); to Aspidoganoidei by Hay (1902); to Monorrhina by Obruchev (1964); and to Agnatha by Dineley and Metcalf (1999).
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.