Figure 2. Morphometric analysis of Bouchardia antarctica shells from before and after the 41-Ma cooling event.

Shell-morphology scores for the first two principal components explain 97.7% of the among-site variability. PC1 describes variability in size and PC2 represents variability in shape. Sites B-1 and 94-18 predate the cooling event, whereas sites 94-11 and 94-12 postdate the event.