Dessicated shark carcass?  Not quite.  This is actually a very intricately designed piece by Tony Fredriksson from Open Sky Wood Art, made entirely out of driftwood.  Tony is well known for recreating animals and elaborate installations by assembling pieces of wood that have been recovered from the ocean.  Since the wood has gone through a large amount of weathering, they really add to the style of decay that is conveyed by his work, and are rather convincing when complete.  Check out his website or review the Fish section to see what goes into each one.