Dinosaur Cold Case

So this is a perfectly cold and shelved case. A Canadian dredger digging a hole in the oil sands of Alberta came across something strange - a hard object covered in strange stains. It turned out to be a perfectly preserved corpse, buried for a long time... for a very long time... 110 million years, in fact. The "victim" is a fully intact ankylosaurus, a completely untouched fossil of a new species of "armored" dinosaur. Paleontologists from Canada's Royal Tyrrell Museum are working like forensic detectives to unravel its mystery. Where did it come from, why was it found upside down hundreds of kilometres from land in an earlier inland sea, how did it die, and how did it fossilise so perfectly into its full 3D glory?