@KikyGames The fin placement…yes it is perfect for what it is used for, but still some fins did evolve into arms and legs. That is the enviroment factor.
sorry, i got distracted and also my typing in english is slow 
@KikyGames Well I was talking about what evolution can do if the planet is not earth in it’s real state.
look to the carboniferous
an alien world
tons of O2
giant bugs

fascinating but scary
imagine waking up and that is on ur flor

my reaction would be like: Burn it! Burn it all!
i whoud sleep with a shotgun
yeah something like that
and every where is a jungle
with tall trees
the worst
there is a eagle iszed dragonfly
their kill rate is 100%