Zenaspidida

Zenaspidida
Fossil of Zenaspis powriei
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Agnatha
Class: Osteostraci
Order: Zenaspidida
Stensiö, 1958
Subgroups
Synonyms

Zenaspida

Zenaspidida is an extinct order of osteostracans, a group of jawless stem-gnathostomes. They possessed a distinct headshield, which varied in width to length ratio by species.