Upper cretaceous ammonites from Jamaica and their stratigraphie and paleogeographic implications

Nine ammonite species from the Upper Cretaceous of Jamaica are revised and described briefly, including one new species, Pachydiscus (P.) jamaicensis n., of Lower Campanian age. The Cretaceous ammonite fauna is classified into four different levels: Level 1 with Perotticeras cf. moureti Grossouvre, Lower Coniacian; Level 2 with Nowakites lemarchandi (Grossouvre), late Santonian; Level 3 with Pachydiscus (P.) koeneni Grossouvre and Glyptoxoceras retrorsum (Schlueter), early Campanian; and Level 4 with Pachydiscus (P.) oldhami (Sharpe), late Campanian. No older pelagic facies have been recognized. These ammonite levels correlate perfectly with inoceramid zones proposed by Kauffman (1966). The biostratigraphy established in this paper facilitates correlation between the different sedimentary facies of the scattered and isolated Upper Cretaceous outcrops in Jamaica. Paleobiogeographic relations can be established with Europe (Level 4), southern India (Level 3), Madagascar (Level 2), and Japan (Level 1).