Faunal realms in Jurassic and Cretaceous belemnites

In reply to discussion by R. Bowen to a paper originally published in 1963 (for reference, see this Bibliography Vol. 29), Stevens summarizes evidence in support of the conclusion that Mesozoic faunal realms or provinces were essentially similar to those of present-day oceans. It is noted that presently available oxygen isotope data are not sufficiently abundant to disprove paleobiogeographic evidence.