[Kingdom] Animalia Linnaeus, 1758 - animals Grade Enterozoa Grade Cœlomata Phylum Vertebrata (Lamarck, 1801) Branch Craniata Linnaeus, 1758 Grade Gnathostoma Subgrade Pentadactyla branchiata Class Amphibia Gray, 1825 Subclass Phractamphibia Haeckel, 1866 Order Labyrinthodonta 1 Genus Archegosaurus Goldfuss, 1847