Sorry, what Dr. Shubin found was NOT a tetrapod,
Right (HitchSlap, shame on you - Tiktaalik is no more a fully formed tetrapod than Archaeopteryx is a fully formed bird). It also wasn't a fish. It was a creature clearly showing signs from both groups, making it an
ideal transitional fossil.
it was a fish with two bones in its fins that kind'a look like two of the many bones in the wrists of tetrapods.
Do you really think that's the only significance? You can find all of the significant features on this handy-dandy
interactive website. Yes, the bones in the fin are of particular significance, as they show a clear relation to the telling tetrapod structure (which you are
extremely unlikely to find outside of that clade), but they aren't the only thing that clearly identify Tiktaalik as not merely a fish with some weird bones. The positions of its eyes, the shape of its head, the disconnect between the head and the shoulders allowing for head movement, the
ribs - none of these are features you will find in fish. They are, however, perfectly typical of tetrapods. On the other hand, it has fins, scales, and gills, which are very atypical of tetrapods but which are standard for fish.
As Shubin said in his book on the subject:
[F]or me the greatest moment of the whole media blitz was . . . at my son’s preschool. . . . The first child said it was a crocodile or an alligator. When queried why, he said that like a crocodile or lizard it has a flat head with eyes on top. Big teeth, too. Other children started to voice their dissent. Choosing the raised hand of one of these kids, I heard: No, no it isn’t a crocodile, it is a fish, because it has scales and fins. Yet another child shouted “Maybe it is both.” Tiktaalik’s message is so straightforward even preschoolers can see it (p. 25).
There isn't exactly some huge debate with paleontology of the significance of Tiktaalik, despite the protestations of the Discovery Institute.
Which means there should be a very large number of transitional fossils that can be arranged to show a clear transition from fish to tetrapod.
...All of which means very little if fossilization is a rare thing to happen. Which it is.