Whilst birding the Ash Shargiyah Development Company Farm (Fadhili) with Phil Roberts we found a large number of Sand Swimmer Zophosis complanate. Sand Swimmer is a darkling beetle that is normally found in sand dunes.
They prefer soil with some clay in them and the ones we found were near a wet sabkha area and reeds with the sand having at least some clay content. Their exterior is smooth allowing them to swim through sand often just below the surface.
The beetles we saw were being predated by a Sacred Scarab Scarabaeus sacer, which I do not know if it common or not, but the Sand Swimmers did not appear concerned about the Scarab Beetle at all.