Fig. 2

Morphological integration as described by a two-block PLS analysis of the left and right valves of all 669 specimens. Most equivalve specimens are distributed along the central axis of the scatter, and most inequivalve specimens would lie furthest from the central axis. Thin-plate spline warped surface scans depicting valve shape at the minima and maxima of PLS1 for the left valve and PLS1 for the right valve are shown, to the right and left of the biplot respecively