Columbia subject headings:
Harvard subject headings:
Ammonoidea--South Dakota.
Ammonoidea--Wyoming.
Paleontology--Cretaceous
Paleontology--Fox Hills Formation.
Paleontology--South Dakota.
Paleontology--Wyoming
Scaphitidae.
Princeton subject headings:
Paleontology--Cretaceous.
Paleontology--South Dakota.
Paleontology--Wyoming.
Scaphitidae.