Number of Classes in Chordata: 14
Chordata

Actinopterygii
[43,282]
Amphibia
[3,472]
Ascidiacea
[803]
Aves
[14,907]
Cephalaspidomorphi
[301]
Cephalochordata
[249]
Elasmobranchii
[5,385]
Holocephali
[173]
Mammalia
[25,897]
Myxini
[91]
Reptilia
[2,364]
Sarcopterygii
[21]
Thaliacea
[3]
unknown
[244]