Fig. 7. Limb positions relative to size for juvenile to adult basilisks. The left-hand column shows a series of frames of a basilisk at the start of slap for a size range of lizards. The backgrounds of the frames are all 2 cmx2 cm grids. The central and right-hand columns are two-dimensional overlaid stick figures of limb positions during the support phase of aquatic running for the run represented in the adjacent frame. The hip, knee, ankle and foot (i.e. metatarsal–phalangeal) points are represented in each set of figures, with the hip at the upper end and the foot at the lower end of each stick figure. In all three columns, the basilisk is running from the right to the left. The dotted, horizontal line in the central column represents water level. The right-hand column figure is created from the same trial as the figure in the left-hand column, but with the position of the toe fixed. The highlighted (green) stick figure represents the limb position shown in the left-hand column video frame. Relative velocities were calculated by dividing by snout–vent length (SVL) and are presented as body lengths per second (L s^–1). (A) 2.8 g, 0.84 m s^–1 or 17.8 L s^–1; (B) 11.4 g, 1.6 m s^–1 or 21.2 L s^–1; (C) 20.8 g, 1.38 m s^–1 or 15.2 L s^–1; (D) 78.0 g, 1.00 m s^–1 or 7.56 L s^–1. At comparable speeds (A–C), heavier lizards exhibited greater limb excursions. Also, whereas lighter lizards (weighing <20 g; A,B) usually slapped the water surface toe first or flat-footed, heavier lizards (>20 g; C,D) slapped the water heel first.