Reef coral diversity in the Late Maastrichtian of Jamaica

摘要

The Jamaican Cretaceous succession includes rich assemblages of fossil macroinvertebrates that date from the latest Maastrichtian. Reef corals are an important component of these assemblages and are found in abundance in many of the 27 Cretaceous inliers across Jamaica. In the present work, we have analysed results from detailed sampling of three of these inliers (Central, Marchmont and Maldon) to make estimates of coral species richness and diversity immediately prior to the K-T boundary. From more than 1350 identified scleractinian and octocoral specimens from 47 sample sites, a total of 58 species from 39 genera were recognized. Bulk collections (441 specimens) from a single –1m thick bed in the Guinea Corn Formation of the Central Inlier yielded 35 species from 28 genera. An analysis of sampling using jack knife estimates of species richness and localitysampling curves suggests that this data gives a reasonably accurate estimate of richness in the Jamaican terminal Cretaceous. Taxonomic richness of this Maastrichtian assemblage is high relative to known faunas from the Caribbean Cenozoic. Richness in the extensively sampled unit in the Guinea Corn Formation is also comparable to that in similarly well-sampled units in the Cenozoic of Jamaica. This data stands in stark contrast to the species-poor Caribbean faunas of the Paleocene through Early Eocene.