Triassic kraken: the Berlin ichthyosaur death assemblage interpreted as a giant cephalopod midden. 2011.M.A.S. McMenamin and S. McMenamin, 2011 GSA Annual Meeting in Minneapolis (9–12 October 2011).
McMenamin noted different degrees of etching on the bones that suggests that the shonisaurs were not all killed and buried at the same time. It also looked like the bones had been purposefully rearranged (below). That it got him thinking about a particular modern predator that is known for just this sort of intelligent manipulation of bones.
But could an octopus really have taken out such huge swimming predatory reptiles? Watch this video :