Ichthyosaur tail vertebrae

Outside the main Fossil House, Berlin-Ichthyosaur State Park, Nevada, USA. They've built a shelter over a world-class display of ichthyosaur fossils. Ichthyosaurs were (more or less) the reptile equivalent of dolphins (porpoises); they looked like fish and were marine but were air-breathing. The ichthyosaur here is Shonisaurus popularis of late Triassic age. It's named from the Shoshone Mtns where the fossils occur.
This section the rangers cover with a thin layer of dirt and then let the kids use whisk brooms to sweep it off, so they can "discover" a fossil! Kind of a nice interactive idea.