Rise and fall of Pliocene free-living corals in the Caribbean

Climate change is currently having an impact on shallow-water corals, and global circulation models predict that levels of pCO(2) and temperature will rise within the next century above anything recorded for at least the past 650 k.y. The Pliocene Epoch is a recent, albeit imperfect, geologic analog for such conditions in the Caribbean. Diverse communities of free-living solitary and flabelo-meandroid (FSFM) corals inhabited shallow nearshore to deeper oligophotic habitats of the Pliocene. FSFM corals were well suited to the low-angle depositional profiles, increased productivity, increased sedimentation, and warmer temperatures of the Pliocene. Origination rates of FSFM coral species between 8 and 4 Ma are roughly double other zooxanthellate corals. FSFM corals underwent abrupt extinction between 2 and 1 Ma, as environmental conditions changed and suitable habitat was eliminated. The evolutionary bottleneck of Pliocene-Pleistocene extinctions and relic steep-margined Pleistocene topography may leave modern faunas vulnerable as we return to Pliocene-like conditions.