"Note that fossils separated by more than about a hundred thousand years cannot show anything about how a species arose. Think about it: there could have been a smooth transition, or the species could have appeared suddenly, but either way, if there aren't enough fossils, we can't tell which way it happened."
Your link speaks a lot of "we found a foot, we found a fin, we found a vertebrae. Perhaps I missed it, but could you please point me to the part where they have actually found an almost complete "transitional" fossil?
From what I have read in the "Gap" explanation, and what I have skimmed through, there are more questions than answers.
Also, how do they explain the "or the species could have appeared suddenly".