Figure 1
Palaeoenvironmental proxies in the Peniche GSSP section fluctuate across two hyperthermal pulses during the Pliensbachian-Toarcian crisis (PToB and T-OAE). The proxies from left to right are: 2nd order transgressive–regressive cycles to visualise changing bathymetry87, δ13C as a proxy for carbon cycle disturbances42, δ18O as palaeotemperature proxy42, and δ11B as a proxy for ocean acidification42. The grey lines in the background of the isotope curves show the original values42, whereas the thicker lines overlaying them represent the lower-resolution curves with data points only at the positions of the stratigraphic beds sampled in this study (see stratigraphic log on the left). The second-to-right curves show median GPA Centroid size as a body size proxy (grey line shows full assemblage pattern, with shaded area representing median absolute deviation (MAD), C. longiforma and P. bisulcata are shown in green and yellow, respectively, with error bars representing MAD). On the right-hand-side PC1 is displayed as proxy for robustness in purple (for colouration see Centroid Size description). The two belemnite shapes bracketing the robustness curves show typical cross section appearances for C. longiforma (in green on the left) and P. bisulcata (in yellow on the right).
