The first fossil deposit discovered connected with the Cambrian explosion (sudden appearance of all the animal body plans) was Canada’s Burgess Shale deposits high in the mountains near Golden, B.C. Just recently another deposit farther south in Kootenay National Park has been discovered. However other similar Cambrian deposits have been found in China, Australia and Greenland. Most recently a much higher lying community has been found in Morocco. Obviously burial of such creatures was a world-wide event!
If one looks at the design features of these creatures of the Cambrian explosion, such as Anomalocaris (means strange claw and could be as long as one metre or more) and trilobites, we find that they are every bit as well suited to modern lifestyles as the creatures we see today. For example, Anomalocaris was among the first many-celled animals found, yet it was so large and complicated in body plan and behavior (predatory feeding style). It does not fit evolution theory to imagine that creatures with these body plans sprang into existence at a very fast speed (too fast to be explained by natural selection) and that similar creatures then stayed at the same level of complexity ever since. The extant creatures we see exhibit body plans the same as many of the animals of the Cambrian deposits.
The young earth view is that these creatures were beautifully designed for their ecological needs (which were similar to what they would be today). Some of these creatures went extinct in the horrors of the flood, while others survived. The amazing preservation of these soft-bodied fossils demonstrates that they were suddenly and permanently buried (perhaps by turbidity currents). The Burgess Shale is found high in the Rocky Mountains, but geologists consider that this community represents a shallow marine community which was buried by sediments rushing off the land. Others have suggested that the fossils could be an accumulation of creatures swept up from a larger territory in the sea. In any case they do represent sudden appearance of multicellular animals. Later this burial area was raised up in an episode of mountain building.