Is there anyone out there who has studied the "walking catfish" that exists today?
Probably.
Plug in Clarias batrachus into an search engine.
But the walking catfish and this critter have very little in common osteologically.
What the article here does not present is the detailed osteological analysis which has been done on fish of this nature. later primitive amphibians and primitive reptiles
and primitive and modern mammals.
The fossil evidence indicates that if they didn't follow a progressive evolution along the lines we suspect, more or less, the Almighty has decided to play quite a joke on us for no apparent reasons.