with the original matrix,
Upper Cretaceous Era (circa 65 million years old),
South Dakota, United States of America. The ammonite 11.5ins.(29cm)wide, Matrix 13x5.1ins.(33x13cm)
A scarce ammonite with its original matrix. It displays a brilliant opalescence in a deep red colour. The ammonite is completely detachable from the matrix (fitting neatly within); the opalescent shell layers to be seen beneath the ammonite and in the host rock nodule.