>>213468046No. Climate and environment has a lot to do with it. In that region at that time, the climate was probably favourable enough to allow for them to leave the water for a few seconds, whereas elsewhere in the world the conditions would be different. Maybe there was something to eat on the shore there that wasn't found elsewhere. Who the fuck knows. But the point is that the one fish who could remain on the shore longer than the other ones had an advantage, procreated, shared those genes and eventually became the dominant race. Then a hundred years later another mutation allowed some to stay for a minute instead of twenty seconds, so that one got the fattest and had the most babies. Etc.
Fish and marine life still exist today. Elsewhere in the world they probably never had to go on the shore in the first place because everything they needed was in the water anyway, so those that did evolve to go on the shore had no benefit from it at all, didn't massively procreate as the alpha and eventually died off. It's all random, and some random mutations will work well in the environment it finds itself in.