Fig. 3. Timing of divergence between Caribbean (blue) and Tropical Eastern Pacific (red) environments and ecologies in coastal, shallow, and deep waters.

(A and B) Estimated mean annual range of temperature [MART; a proxy for strength of upwelling estimated by measuring zooid size variation in fossil bryozoan colonies (133)] (A) and the relative skeletal weight of corals and coralline algae (68, 134) (B) in replicated bulk samples from coastal shelf sediments on the Isthmus of Panama. (C and D) Rates of accumulation of carbonate (CMAR) in deep-sea sediments (C) and estimated surface water salinity (reflected in the oxygen isotope record) (D) in Caribbean and Pacific surface waters. (E) Neodymium (Nd) values from fish teeth and foraminifers in Pacific and Caribbean basins (35, 38).