Cephalaspidomorphi

Cephalaspidomorphs Temporal range: 436–359 Ma PreꞒ Ꞓ O S D C P T J K Pg N Cephalaspidomorphs would survive to the present day if lampreys are included (possible offspring in the gnathostomes)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Infraphylum:	Agnatha
(unranked):	†Cephalaspidomorphi
Type species
†Cephalaspis lyelli Agassiz, 1835
Subgroups
†Osteostraci †Galeaspida †Pituriaspida Gnathostomata?

Cephalaspidomorphs are a group of jawless fishes named for Cephalaspis of the osteostracans. Most biologists regard this taxon as extinct, but the name is sometimes used in the classification of lampreys, because lampreys were once thought to be related to cephalaspids. If lampreys are included, they would extend the known range of the group from the Silurian and Devonian periods to the present day. They are the closest relatives of jawed fishes, who emerged from within them and they would survive if the jawed fish are included.