Labyrinthodontia
"Labyrinthodontia" (from Ancient Greek λαβύρινθος (labúrinthos, meaning "maze", and ὀδούς (odoús), meaning "tooth") is an informal group of extinct predatory amphibians which were major components of ecosystems in the late Paleozoic and early Mesozoic eras (about 390 to 150 million years ago). Traditionally considered a subclass of the class Amphibia, modern classification systems recognize that labyrinthodonts are not a formal natural group (clade) exclusive of other tetrapods.