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We provide a description of the remains of a fossil whale from western Panama. The record consists of appendicular remains of a mysticete, which has been assigned to Balaenopteridae. These remains, found in the sediments of the late Pliocene Burica Formation, represent the first record of a marine mammal in the Neogene sedimentary succession of the Burica Peninsula. Two different types of shark bite marks, serrated and deep-unserrated, found on the radius and phalanges suggest scavenging by at least two white shark (Carcharodon) individuals. The deep, unserrated marks were possibly caused by continual biting by sharks. Both the morphology of the shark bite marks and their relative location on the whale limb bones constitute evidence of shark-cetacean trophic interaction. Although the specimen lacks diagnostic features that would allow a species-level identification, it does provide new information on the vertebrate fauna of a very poorly prospected Central Eastern Pacific exposure, thus opening an opportunity for exploring the marine fauna during a critical episode in Earth history, the Plio-Pleistocene transition. Dirley Cortés. Redpath Museum, McGill University, 859 Sherbrooke St. W., Montreal QC H3A 0C4, Canada. Smithsonian Tropical Research Institute, Balboa-Ancón 0843-03092, Panamá, Panamá. dirley.cortes@mail.mcgill.ca Carlos De Gracia. Smithsonian Tropical Research Institute, Balboa-Ancón 0843-03092, Panamá, Panamá. degraciac@gmail.com Jorge D. Carrillo-Briceño. Paläontologisches Institut und Museum, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland. Smithsonian Tropical Research Institute, Balboa-Ancón 0843-03092, Panamá, Panamá. jorge.carrillo@pim.uzh.ch Gabriel Aguirre-Fernández. Paläontologisches Institut und Museum, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland. gabriel.aguirre@pim.uzh.ch Carlos Jaramillo. Smithsonian Tropical Research Institute, Balboa-Ancón 0843–03092, Panamá, Panamá. ISEM, U. Montpellier, CNRS, EPHE, IRD, Montpellier, France. Jaramillo

The Cantaure Formation (Burdigalian to ?early Langhian) is located in the Falcón Basin, North Western Venezuela, and includes one of the most diverse Neogene teleostean and benthonic invertebrate faunas in Tropical America. The paleoenvironmental preferences of the members of this fauna, as well as published paleogeographic reconstructions, suggest that the Cantaure Formation was deposited in a highly-productive shallow water environment, associated with coastal upwelling. We documented a paleodiversity of 39 shark and ray species, including 15 previously unreported taxa for Venezuela and six for Tropical America. We performed a bathymetric analysis of the fossil assemblage based on the distribution of closely-related extant chondrichthyan relatives of fossil taxa and discuss the ecological role and stratigraphic significance of the latter. Our results support the hypothesis that the Cantaure Formation was deposited in an insular inner-middle shelf environment. The elasmobranch fauna is characterized by a predominance of benthopelagic sharks with piscivorous feeding preferences (e.g., †Paratodus, Galeorhinus, Hemipristis, Rhizoprionodon, Carcharhinus, Isogomphodon, Negaprion, †Physogaleus and Sphyrna) followed by durophagous/cancritrophic feeders (e.g., Heterodontus, Nebrius, Mustelus, Rhynchobatus, Pristis, Dasyatis, cf. Pteroplatytrygon, cf. Taeniurops, Aetobatus, Aetomylaeus and Rhinoptera). Filter (e.g., Mobula and †Plinthicus), eurytrophic/sarcophagous (e.g., †Carcharocles and Galeocerdo) and teuthitrophic (e.g., Alopias) feeder species were also found. Teeth of Carcharocles megalodon found in Burdigalian sediments of the Cantaure Formation support the presence of this species already in the early Miocene. Some taxa (Nebrius, Carcharhinus cf. C. macloti and Rhynchobatus) are absent from the extant Caribbean and Western Atlantic fauna, but were present in the region before the closure of the Central American Seaway.