POWRE: Comparitive role of scleractinian corals and ancient rudist bivalves in Cretaceous reefs: Implication for changes in reef composition in a future greenhouse world

Indiana University, Bloomington IN

Investigators

Abstract

0074603 Johnson Cretaceous strata of the Caribbean region can provide a testing ground for studying macroevolutionary processes in a reef ecosystem of a greenhouse world. Caribbean coral-algal systems were inherited from the Jurassic, and corals and rudists then co-inhabited the carbonate platforms; rudist bivalves eventually dominated many of the Caribbean platforms. Middle Cretaceous coral and bivalve paleobiota from reefs in the core and northern margin of the tropics will be analyzed for taxonomic composition and morphologic characters. The hypothesis to be addressed involves the mechanism of change in dominance of the two groups: is only the environment driving evolution, are there taxonomic, morphologic, and ecologic factors to consider, or is the change in dominance a macroevolutionary process involving both environment and the ecologic characteristics of the co-existence of the two groups? The presence or absence of macroevolutionary trends noted from this study will be a substantial contribution to our knowledge of evolutionary processes operating in the tropics during a greenhouse world. This study is appropriate for POWRE because funding opportunities for such work in order to research a fundamental question of evolutionary theory in the tropics: are macroevolutionary processes operative in the tropics during a greenhouse world?