Unless the footprints come from the current top surface it is not clear to me that they would be more flattened than they already are. If the sand at the top were looser then it might be more affected by compression.
And if erosion is the answer then it doesn't matter if the erosion happened when the area was sand (before it was buried) or after it had lithified. Asking which would be more easily eroded is no answer, because the time is available for either to happen.
This message has been edited by PaulK, 05-12-2005 02:50 AM