Andreas Johansson wrote offlist:
Laurin's Stegocephali "all choanates more closely related to Temnospondyli than to _Panderichthys_". It's thus a bit bigger than Apo-Tetrapoda, and includes _Tiktaalik_.
Oh yes, true. *T.* wasn't discovered yet when the definition was coined. -- So Labyrinthodontia has got to be the smaller one, then.