Thank you! :-) Last sentence of the abstract:
We present examples of pertinent character state distributions and
> explore a large gap in the fossil record of small stegocephalians.By "stegocephalians", Michel means tetrapods in the traditional (apomorphy-based) sense (well, the definition turned out to make *Tiktaalik* a stegocephalian, but that's close enough). He supports restricting the name Tetrapoda to the crown group; we completely avoid that name in the paper.
...And I just noticed that "stegocephalians" implies amniotes as well as others; small amniotes are represented throughout the time in question, even though they're not terribly abundant -- but they're not what we mean.