Answer: yes it is I think
Explanation:
That represents geographical isolation.
Biological isolation is present where members of species are not able to produce fertile offspring due to the genetic incompatibility.
Temporal isolation includes differences in the seasons of mating. One species mates in season x and another in season y, means they will not be able to interbreed.
Anatomical isolation means there are differences in the physical structures of the species members that inhabit their ability to mate.
I think that since it lives on the ocean floor, at the deepest of the ocean. So anyway, the fin on the Eurypterids is still necessary but not that much, since they live on the ocean floor. Their movements mostly on the ocean floor. So fin would not help them "stick" to the floor. Also there are still gravity acts on the Eurypterids and the feet would help them move faster. Hope this helps.
