[Zardoz]

Anti-evolutionists hate this sort of thing:

Dolphin reveals an extra set of ‘legs’ - Scientists say fins may represent throwback to ancient land-dwelling ways

$this->bbcode_second_pass_quote('', 'T')hough odd-shaped protrusions have been found near the tails of dolphins and whales captured in the past, researchers say this was the first time one had been found with well-developed, symmetrical fins, Hayashi said.

"I believe the fins may be remains from the time when dolphins' ancient ancestors lived on land ... this is an unprecedented discovery," Seiji Osumi, an adviser at Tokyo's Institute of Cetacean Research, said at a news conference televised Sunday.

[NEOPO]

Try not to limit these things.

It may be evolution, it may be regression or the whole thing might be a screwed up perspective based only on what we now understand.
Give us some time and we may come up with a better theory then evolution or creation.

I mean really - life may have went from land to water to air back to land or water etc etc.. many times.

I feel ultimately we are just beginning to scratch the surface.