Synonym: Arthrodiriformes Grande and Eastman 1986
Parent taxon: Placodermi according to G. C. Young and J. A. Long 2014
See also Bryant 1932, Denison 1975, Denison 1978, Dineley and Metcalf 1999, Gadow 1898, Grande and Eastman 1986, Hay 1902, Jobbins et al. 2022, Long 2011, Nelson et al. 2016, Obruchev 1964, Straka and Semken 1969 and Young 2010
Sister taxa: Acanthothoraci, Acanthothoraciformes, Antiarcha, Antiarchiformes, Asiacanthus, Austroptyctodus, Bianchengichthys, Brindabellaspida, Campbellodus, Changyonophyton, Coccostei, Coelosteichthys, Deinodus, Entelognathus, Hybosteus, Neopetalichthys, Nessariostoma, Oestophorus, Petalichthida, Petalichthyida, Petalichthyida, Phyllolepida, Pseudopetalichthyida, Pseudopetalichthyiformes, Ptychostei, Ptyctodontida, Rhenanida, Rhenaniformes, Sedowichthys, Stensioellida, Tollichthys, Wangolepis, Yunnanacanthus
Subtaxa: Acanthaspida Actinolepidoidei Actinolepina Africanaspis Antarctolepis Arctolepidae Arctonema Arenipiscis Aspidichthys Atlantidosteus Brachydeirina Brachythoraci Brachythoracoidei Bruntonichthys Bullerichthys Bungartiidae Burrinjucosteus Callognathus Camuropiscidae Coccosteina Copanognathus Cosmacanthus Cravenaspis Diplognathus Erikaspis Errolosteus Eskimaspis Euarthrodira Eubrachythoraci Glyptaspis Goodradigbeeon Grazosteus Groenlandaspididae Harrytoombsia Heintzosteus Heterostiina Hollardosteus Holonematina Huaningichthys Incisoscutoidea Kendrickichthys Kimberleyichthys Kueichowlepis Latocamurus Laurentaspis Lurapullaspis Machaerognathus Mcnamaraspis Murmur Mylostomatidae Operchallosteus Overtonaspis Pachyosteidae Pachyosteina Parawilliamsaspis Phlyctaenina Phlyctaenioidei Phylctaeniida Phyllolepidoidei Platyaspis Prescottaspis Qataraspis Rhachiosteidae Rolfosteus Selenosteidae Squamatognathus Stegophthalami Taemasosteus Taunaspis Temnothoraci Timanosteus Titanichthyidae Toombalepis Toombsosteus Torosteus Trachosteus Tubonasus Tyriolepis Wheathillaspis Wuttagoonaspina Yinosteus
Ecology: nektonic carnivore