It seems to me that fish, of all living creatures, should be the most capable of escaping death by flood. Doubtless there are cases where fish were suddenly buried under sediment. Do fish fossils exist in all parts of the world? I understand whale bones have been found in the desert.
The Burgess shale, in particular, contains the fossils of all sorts of worms, arthropods, sponges, etc. The way they are positioned in the rock indicates that they were caught in an underea mudslide.
There are no fish bones, scales, teeth, or any other indications of fish.
Why?
Why is this true in all lower and middle Cambrian formations?
Why are fish found in all later marine formations?
In fact, in the Burgess shale, there are no indications of any vertebtrate animal. No fish, no whales, no sea snakes, no sea turtles, no birds, no otters, nothing.
Why do you ask questions when you have no intention of responding honestly to the answer? In the first place, by asking elementary questions you expose yourself as pathetically ignorant.
That's all right by itself, because all of us are ignorant in varying ways and degrees.
But your questions are personally and intellectually dishonest. You don't know the answer, and you have no intention of being informed by the answer.
The Burgess Shale species could swim.
Fish fossils are found below terrestrial animal fossils.
The order of fossils indicates a slow progression from smaller to larger fossils, aquatic to terrestrial, terrestrial to airborne; fish to amphibian, amphibian to reptile, reptile to mammal and bird. There is no sorting by size, weight, length of leg, running ability or the ability to tread water for a really really long time.
No unnecessarily absurd hypothesis can explain this sorting in light of a world wide flood.
The fossil record does not match a world wide flood.