I suppose that people have discussed this before. If you could post a link to the theread I would be happy to read it. 18 million years before the tiktaalik a tetrapod was already walking on earth. This would setback tertapod evolution. I know that the tiktaalik is not expected to be THE transition between fish and tetrapods, but does this complicate stuff.
Tetrapods are older than we thought!
Edited by CoolBeans, : No reason given.