Columbia subject headings:
Echinodermata, Fossil.
Paleontology--Oklahoma.
Paleontology--Ordovician.
Harvard subject headings:
Echinodermata, Fossil.
Paleontology--Oklahoma.
Paleontology--Ordovician
Princeton subject headings:
Echinodermata, Fossil.
Paleontology--Oklahoma.
Paleontology--Ordovician.