FIGURE 1. Geological setting of the find. 1, Map of Central America, showing the Burica Peninsula. 2, Geological map of the Burica Peninsula, indicating the fossil locality. 3, Schematic chronostratigraphic section, showing the approximate position of the whale remains. Map modified from Coates et al. (1992); ages from Corrigan et al. (1990) and Schwarzhans and Aguilera (2013). Ma: million years; Fm., Formation.

FIGURE 2. 1, Right lateral view of the skeleton of a generalized mysticete whale (modified from Marx and Fordyce, 2015; Marx et al., 2016). 2, Dorsal view of the reconstructed forelimb of specimen MNUP-1795 from the late Pliocene of Panama. Abbreviations: H, humerus; MCA, metacarpal A; MCB, metacarpal B; OP, olecranon process; PA, phalanx A; PB, phalanx B; PC, phalanx C; R, radius; U, ulna. Roman numerals indicate the digits of the right forelimb.

FIGURE 3. Balaenopterid and shark remains from the late Pliocene of Panama. 1-4, Bones affected by shark bite marks, with close-up photographs and line drawings of the incisions (1-3: phalanges; 4: radius). SB = Serpulids and bryozoans covering the surface of the fossil bones and partly draping the underlying bite marks. 5, Carcharodon carcharias tooth (MBML-CF01) found near the cetacean remains. Abbreviations: PA, phalanx A; PB, phalanx B; R, radius. Colors on bite marks line drawings indicate the differentiation of the bite damages by two potential and different-sized conspecific shark individuals.