We hypothesize that the shonisaurs were killed and carried to the site by an enormous Triassic cephalopod, a 'kraken,' with estimated length of approximately 30 m, twice that of the modern Colossal Squid-- from here.
P Z Myers is sceptical :
This 'Triassic kraken' has not been found; no fossils, no remains at all, no evidence of its existence. It is postulated to have been large enough to hunt and kill ichthyosaurs, which is remarkable—comparison to modern giant squid is invalid, since they are prey, not predator.P.S. 11 Oct: Microecos has some fun, but Nature does not dismiss the idea out of hand.