So, I've been looking for a solution to the question: Why did vertebrates fail to flourish on Myrmecos?
I think I have the answer: No Armored Fishes.
If there were no armored fish then the Eurypterids would have continued to be apex predators longer. Some might have filled the hunting niche of early tetrapods. Arthropods were already on land, but you get a second wave.
The land gets built up with arthropods and fish are trapped in the seas!
And in this universe earth is the exception. Not only is earth far away from all of the other living planets it's one of the few with land vertebrates.
The armored fish driving tetrapods on to land was a kind of ripple in the intended pattern. It threw everything off!
And just looking at The Dunk-- it is kind of unnatural, don't you think?
This also means that the ants will keep describing humans as "intelligent life from the sea" -- even as we keep explaining that everything came from the sea and it was a long time ago...
To them having a backbone means you are adapted to living in the water.
"The human body's design spec is: a spacesuit for a fish."
(Ken MacLeod, "The Cassini Division")
myrmepropagandist
Ángela Stella Matutina