>>109301846See, none of that actually is true.
Neither the square cube law nor convergent evolution work against any of the fauna we see in the show. None of the animals we see are unreasonable within the logic of the show.
The only thing you could really speculate on is whether or not
a) two intelligent species can exist on the same planet alongside each other (assuming toads and frogs are not able to interbreed), since in the history of our own species, at any point where speciation could have occurred or did occur, all diverging species died out long before we formed a society
and
b) an intelligent species with as many natural predators that are so much larger than them can survive long enough to build a civilization in the first place.
Humans were predated on a lot as well, of course, but the environment of amphibia is many times more hostile than ours was.
