This is a CT-generated movie of the premaxilla of Diplodocus (YPM 4677), with bone rendered transparent and teeth opaque.
Credit: D’Emic MD, Whitlock JA, Smith KM, Fisher DC, Wilson JA (2013) Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs. PLoS ONE 8(7): e69235. doi:10.1371/journal.pone.0069235
[ Read the Article: Teeth Continuously Replaced In Large Sauropod Dinosaurs ]