The ammonite shown is about 6.35 cm in diameter. Considerable rainbow-like nacreous material remains on the exterior of the fossil.

Another angle of the same specimen, showing the dense assemblage of other fossils in the shale matrix.

Ammonite from the Late Cretaceous Pierre Shale (75 mya) of South Dakota, probable Hoploscaphites sp. Purchased from the Discovery store. In my collection.

#fossilfriday #ammonite #coleoid #preservation