vertebrates Lamarck, 1801 - vertebrates see Infraphylum Vertebrata Lamarck, 1801 Class †Pteraspidomorphi Goodrich, 1909 see Class Pteraspidomorpha Subclass †Heterostraci Lankester, 1868 Order †Cyathaspidiformes Kiaer, 1930 Family †Cyathaspididae Kiaer, 1932, nom. praeval. 1 Genus †Seretaspis Stensiö, 1958 [monotypic]