now that's funny
Great stunt ER, just great.
There's a ranch near Canon City, Colorado, with an amazing exposure of Cambrian rocks. The statigraphy is nearly horizontal and composed of a very fine grained, tan, calcareous shale. When it was deposited, it was the limey muddy bottom of a shallow Cambrian sea. Preserved for more than 500 million years are the tracks and burrows of all those critters you mentioned, and many other besides. Hundreds of different types of "trace fossils" have been identified over about two acres of exposed rock. It's like looking at the sea floor as it was back then ... a little glimpse of time travel.