The very fact that there are so many fossils, in the layers suggests that there have been a great many, or a few very tremendous and sudden catastrophies in the history of the earth.Considering the 100's of millions of years life has existed on Earth, we have relatively few fossils. It's hard enough finding fossils of our own species.
There are full large mammals frozen in the ice, with food still in their stomachs! This had to happen in a major hurry!The freezing conditions would preserve any animal. If you found an entire herd of Mammoths frozen together, that may be a different story.
If there have been such major catastrophies in the history of the earth, we must be very flawed in thinking that things have changed at the rate we currently observe.You mean like the extinction of the dinosaurs 65 million years ago? It doesn't take worldwide catastrophies to give us fossils. Earthquakes, volcanos, local flooding etc. all contribute.
Also the environment in which the creature lives and dies contributes to whether or not fossil records will be easily come by.
™ Version 4.2