Zooxanthellate scleractinian corals of the Bowden shell bed, southeast Jamaica

The zooxanthellate coral fauna of the Bowden shell bed in southeast Jamaica consists of 38 species, and is dominated by extinct free-living species belonging to the genera Manicina, Thysanus, Trachyphyllia, Placocyathus and Antillia. Eighteen of the species are free-living, eleven are massive and nine are branching. Only nine of the 38 species are extant, and all but one species are distributed throughout the Caribbean region. Assuming a geologic age of 3.8-2.7 Ma for the Bowden shell bed, eight of the 38 species have global last occurrences in the Bowden Formation, and eight have global first occurrences either in the Bowden Formation or in units of equivalent age elsewhere in the Caribbean. Recent collections made at closely spaced intervals through the Bowden-Old Pera sequence reveal a shift between ~3.3-1.8 Ma from extinct free-living species to extant branching and massive species. The Old Pera collections contain a mixture of Caribbean coral species that dominated Caribbean reefs before or after an episode of accelerated faunal turnover between 4-1 Ma, and thus represent a transitional fauna. Most notable among the Old Pera species is the co-occurrence of now extinct Stylophora granulata and extant Acropora cervicornis. New stratigraphic data reveal that 18 of the 37 Old Pera species have global last occurrences in the Old Pera beds or in units of equivalent age elsewhere in the Caribbean, suggesting that it may have provided a refuge for pre-turnover species. Comparisons with collections of two similar-aged faunas on the north coast of Jamaica, the Manchioneal Formation (2-1.4 Ma) and Hope Gate Formation (1.8-1 Ma), show striking differences that appear related to environmental conditions. The north coast faunas contain high percentages of extant species with massive colony shapes, indicative of exposed, open reef environments. Community change associated with Plio-Pleistocene turnover may have proceeded more slowly in protected, reef margin environments, such as the Old Pera beds.