Alternative spelling: Petalichthida
Synonym: Petalichthyiformes
Full reference: O. Jaekel. 1911. Die Wirbeltiere. Eine Übersicht über die Fossilen und Lebenden Formen [The Vertebrates. An Overview of the Fossil and Living Forms] viii-252
Parent taxon: Placodermi according to G. C. Young 2010
See also Grande and Eastman 1986, Long 2011 and Nelson et al. 2016
Sister taxa: Acanthothoraci, Acanthothoraciformes, Antiarchi, Arthrodira, Asiacanthus, Austroptyctodus, Bianchengichthys, Brindabellaspida, Campbellodus, Changyonophyton, Coccostei, Coelosteichthys, Cratoselachiidae, Deinodus, Entelognathus, Hybosteus, Neopetalichthys, Nessariostoma, Oestophorus, Petalichthida, Petalichthyida, Pseudopetalichthyida, Pseudopetalichthyiformes, Ptychostei, Ptyctodontida, Rhenanida, Rhenaniformes, Sedowichthys, Stensioelliformes, Tollichthys, Wangolepis, Yunnanacanthus
Subtaxa: none
Ecology: nektonic carnivore