Ctenaspididae

Ctenaspidae
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Pteraspidomorphi
Subclass:	Heterostraci
Order:	Cyathaspidiformes
(unranked):	Cyathaspidida
Family:	Ctenaspidae
Genera
See text

See text

Ctenaspidae is a family of extinct cyathaspidiform heterostracan agnathans in the suborder Cyathaspidida.

If Amphiaspidida can be ignored as a daughter-taxon, the family Ctenaspidae contains Ctenaspis and its various sister-taxa originally contained within both Ctenaspididae and Ctenaspididae, including Allocryptaspis, Alainaspis, Zaphoctenaspis, Arctictenaspis, and Boothiaspis, which was first described as a "Canadian amphiaspid."

...
Wikipedia