|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
It was reranked as Onchus (Physonemus) by Agassiz (1837).
It was assigned to Onchus by Agassiz (1837); to Ichthyodorulites by Hay (1902); to Cochliodontidae by Eastman (1903); to Heterodontidae by Jordan (1963); and to Holocephali by Nassichuk (1971).
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.