Fig. 3. Span and chord distributions of the pectoral fin. (A) Mean of spans are standardized by the square root of fin area. The spans are ordered (1–6) from leading to trailing edge. (B) Means of curved chords standardized by mean curved chord. The chords are ordered (1–5) from proximal to distal. Value are means ±1 S.E.M. The species represented by filled circles are ‘flappers’ and the species represented by open circles are ‘rowers’. Sample sizes, N, are given in Table 1.