†order Zenaspidida Stensio 1958 (vertebrate)
Petromyzontida - Cephalaspidiformes
Parent taxon: Osteostraci according to R. S. Sansom 2009
See also Voichyshyn 2006
Sister taxa: Aachenaspis, Fieldingaspis, Meelaidaspis, Ohesaareaspis, Tuvaspis, Camptaspis, Tremataspidiformes, Tremataspidida, Benneviaspidiformes, Thyestiida, Waengsjoeaspis, Yvonaspis, Cornuata, Ateleaspidiformes, Benneviaspidida
Subtaxa: Parameteoraspididae Spangenhelmaspis Superciliaspididae Wladysagitta Zenaspididae
Ecology: fast-moving nektonic carnivore
Distribution:
• Devonian of Canada (2: Northwest Territories, Quebec collections), Latvia (1), Norway (8), Svalbard and Jan Mayen (7), Ukraine (12), the United Kingdom (6)
Total: 36 collections including 64 occurrences