English: A-F, progressive burial of a dinosaur skull (Allosaurus cast) in a water flume with a moveable (live) bed of medium-grained sand. The skull sets up the conditions for it own burial by being an obstacle to flow. Scour occurs on the upstream side due to flow acceleration around the skull ("thumb on the garden hose" effect). Undercut, the skull pivots into the scour hole due to gravity. In the flow shadow (downstream side) water recirculates (reverses direction) and pressure drops causing deposition of the sand that was scoured from the upstream side. Linear sand piles (dunes) pushed along by the water advance and bury the skull. G-H, Computer modeling (Computational Fluid Dynamics) shows why the skull gets buried.