You claimed that all phyla originated not just then, but in the very earliest rock layers. Perhaps you meant differently, but I can only comment on what I see you type.
Yes I did. And it's because of that that I know how incorrect your statement above is. I'm going to try and explain it to you with the hope that you'll look at it with an open mind.
Creatures don't need to be designed. Random chance does the trick because this is how evolution works:
Mutations happen. Most are neutral, some are bad, and some are good. That's random. But this isn't: Bad mutations are eliminated from the population due to the fact that individuals that have them are less fit than their buddies, and therefore die younger and reproduce less, which means that this bad mutation is unlikely to be passed on for more than a couple of generations. Neutral mutations have no effect on fitness, but good mutations have a positive impact. They increase the fitness of an individual, and therefore these individuals are more likely to live longer lives and have more offspring, which will also be more fit if they inherit the mutation and pass it on to their offspring, and so on until the entire population has this good mutation as part of their genome.
So mutation is random. Natural selection is not: positive mutations are selected for, and negative mutations are selected against.