Fig. 2. (A) Kinematics and sutural strains measured during three suction feeding events (Polypterus 1, trial 3, events 1-3; see Table S1 in supplementary material). Still frames of (B) mouth opening, (C) maximum gape and (D) mouth closing are shown for the first suction feeding event. The blue vertical lines indicate the timing of the gape cycle. All strain peaks appear to coincide with maximum gape, and only one peak is observed in each feeding event. The interparietal (IP) suture is loaded in compression, while the interfrontal (IF) and frontoparietal (FP) sutures are loaded in tension.