This is the Acanthostega I was talking about in my journal.

This is the species I'm using as a common ancestor of all the species in the parallel universe I'm making. The story behind it is that in a parallel universe that split from our own 360 million years ago, all potential ancestors of terrestrial vertebrates were wiped out except one - acanthostega - and thus the potential evolutionary path for future terrestrial vertebrates was changed.

Many of the biological factors behind this project will be pure speculation and I don't intend on becoming a professor just to understand how they work - the main focus behind this, after all, is to demonstrate many small changes adding up to bigger changes - you will see that the first few descendants I add will look very much similar to acanthostega, but as their age on the geological timescale becomes younger and younger, their differences begin to add up.