Columbia subject headings:
Paleobiology.
Paleontology, Stratigraphic.
Paleontology.
Harvard subject headings:
Paleobiology.
Paleontology, Stratigraphic.
Paleontology.
Princeton subject headings:
Geology, Stratigraphic--Periodicals.
Paleontology, Stratigraphic--Periodicals.
Paleontology--Periodicals.
Periodicals.