Parent taxon: Placodermi according to R. van der Laan 2019
See also Bryant 1932, Denison 1975, Denison 1978, Dineley and Metcalf 1999, Gadow 1898, Hay 1902, Jobbins et al. 2022, Obruchev 1964, Straka and Semken 1969, Young 2010 and Young and Long 2014
Sister taxa: Acanthothoraci, Acanthothoraciformes, Antiarchi, Asiacanthus, Austroptyctodus, Bianchengichthys, Brindabellaspida, Campbellodus, Changyonophyton, Coccostei, Coelosteichthys, Cratoselachiidae, Deinodus, Entelognathus, Hybosteus, Neopetalichthys, Nessariostoma, Oestophorus, Petalichthida, Petalichthyida, Petalichthyida, Pseudopetalichthyida, Pseudopetalichthyiformes, Ptychostei, Ptyctodontida, Rhenanida, Rhenaniformes, Sedowichthys, Stensioelliformes, Tollichthys, Wangolepis, Yunnanacanthus
Subtaxa: Acanthaspida Actinolepina Africanaspis Antarctolepis Arctonema Arenipiscis Aspidichthys Atlantidosteus Brachydeirina Bruntonichthys Bullerichthys Callognathus Coccosteina Copanognathus Cosmacanthus Cravenaspis Diplognathus Erikaspis Errolosteus Eskimaspis Euarthrodira Eubrachythoraci Glyptaspis Grazosteus Harrytoombsia Heintzosteus Heterostiina Hollardosteus Holonematina Huaningichthys Incisoscutoidea Kimberleyichthys Kueichowlepis Latocamurus Laurentaspis Lurapullaspis Machaerognathus Mcnamaraspis Murmur Operchallosteus Overtonaspis Pachyosteidae Pachyosteina Parawilliamsaspis Phlyctaeniiformes Phlyctaenina Phylctaeniida Phyllolepida Platyaspis Qataraspis Rolfosteus Squamatognathus Stegophthalami Taemasosteus Taunaspis Temnothoraci Timanosteus Toombalepis Toombsosteus Tubonasus Tyriolepis Wheathillaspis Wuttagoonaspina Yinosteus
Ecology: nektonic carnivore