Zenaspidida
| Zenaspidida | |
|---|---|
| Fossil of Zenaspis powriei | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Infraphylum: | Agnatha |
| Class: | †Osteostraci |
| Subclass: | †Cornuata |
| Order: | †Zenaspidida Stensiö, 1958 |
| Subgroups | |
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| Synonyms | |
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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.