Late Cretaceous Maastrichian, approx. 66 - 72 million years ago.
Above water: Under a threatening sky a T Rex is on the prowl, eyeing a herd of Hypacrosaurus. Pterosaurs are Quezelcoatlus.
Under water: In the background a mosasaurus feeds on some ammonites. In front of the mosasaurus are some more ammonites: scaphites. Swimming vertically are some slightly curved baculites. At extreme right are spiral-shaped Turrilites. The amazing ammonites on the seafloor are Didymoceras. On the seaweed at front left are three nostoceras (some shells spiralling in opposite directions). The huge ammonite catching a fish is a Pachydiscus; another is half-shown further down into the depths of the sea.