Modular Growth in Bryozoans and the Inference of Pliocene Climate Regimes

We describe how variation in the modular growth of marine cheilostome bryozoans can be used to infer mean annual ranges in temperature (MART) through the application of the zooid-size MART technique (zs-MART) - an underutilised proxy for estimating seasonal temperature regimes in present-day and ancient environments. Inferences of temperature variation based on analyses of modular growth in bryozoans provide insights on both intra- and interannual environmental variation, and thereby enhance the climate records that are gleaned from foraminifers and other microfossils. The growing body of research to establish and utilise the zs-MART approach demonstrates its wide potential for gaining robust estimates of ancient temperature regimes, particularly when incorporated as part of a multi-proxy toolkit. We review how the zooid-size MART approach has enabled reconstruction of palaeoseasonality for the Pliocene across the North Atlantic, during the closure of the isthmus of Panama and in Antarctica and compare these data with those generated by other biological proxies and with output from GCMs.