Solenoceras, Ammonite (BU791)

Solenoceras sp.

Upper Cretaceous Maastrichtian

Black Mitten Member

Pierre Formation

Custer County, South Dakota USA

Solenoceras is a rare genus of Ammonite from the Upper Cretaceous. It is a heteromorphic Ammonite which changes its direction of growth. It appears as a hairpin and parts have been replaced with golden Calcite.