Stingray at Pango Point

Unidentified Stingray
Cruising down Pango Reef towards the Semle Federsen wreck this large lump in the sand caught our attention. All we could make out was a large gill moving gently, but as we approached the "lump" it turned out to be a huge stingray buried in the sand. It looked strange as it didn't have the normal whip tail that most stingrays have ... it had a stump instead ! What's out there that eats stingray tails, or have we discovered a new creature ?