Many paleontologists prefer a stricter definition of Tetrapoda which applies solely to the crown group, excluding earlier types of limbed tetrapodomorphs.

This name was in reference to the skull form of many early tetrapods, with a low, solid shape combining numerous strongly-textured dermal bones.

In 1998, Canadian paleontologist Michel Laurin repopularized the term and provided a formal phylogenetic definition as a monophyletic clade containing both crown-group and stem-group tetrapods.

[4] In their original usage, Stegocephali (and the Labyrinthodontia) are paraphyletic, the name is now used in an informal way to denote the early non-piscine vertebrates, excluding amniotes (the first reptiles and their descendants) and modern lissamphibians.

[9] Panderichthys Tiktaalik Elpistostege Elginerpeton Ventastega Acanthostega Ichthyostega Whatcheeriidae Colosteidae Crassigyrinus Baphetidae Crown group Tetrapoda As recovered by Clack et al. 2016:[10] Panderichthys Metaxygnathus Tiktaalik Acanthostega Ossinodus Ventastega Ichthyostega Ossirarus Ymeria Aytonerpeton Perittodus Whatcheeria Pederpes Occidens Diploradus Doragnathus Sigournea Koilops Tulerpeton Greererpeton Colosteus Crassigyrinus Loxomma Megalocephalus Baphetes Tetrapoda Temnospondyli Eucritta Embolomeri Gephyrostegidae Silvanerpeton Casineria Seymouriamorpha Lepospondyli Amniota