Abstract
The marine vertebrate fauna collected from the Gatún Formation, middle Miocene of Panama, includes the following genera in the non-otolith assemblage: Carcharodon, Procarcharodon, Ginglymostoma, Hemipristis, Galeocerdo cf. Carcharhinus, Sphyrna cf. Isistius, Dasyatis, Myliobatis, Rhinoptera, Aetobatus, Acipenser, Sphyraena, Trichiurus, Lepisosteus and unidentified crocodilian, chelonian, and mammalian taxa. The otolith assemblage consists of 20 taxa of bony fishes. The fauna contains a mixture of marine forms representing coastal to open-water habitats. The Gatún ichthyofauna compares favorably to the Miocene selachian fauna from Ecuador, the Miocene ichthyofaunas from the Caribbean, and the large ichthyofauna from the Pungo River Formation in North Carolina, U.S.A. These tropical occurrences collectively represent the vertebrate fauna of the Tertiary Caribbean Faunal Province that reached its greatest interoceanic connection between the Pacific and the Caribbean in the Miocene. The provincial limit of the Miocene vertebrates extended beyond the central Gulf of Mexico to include the southeast coast of the United States.