Pre-pleistocene fossil vertebrates are rare fossils in the Antillean region. The majority of vertebrate deposits found in the West Indies are of Late Pleistocene age, usually, but not always (MacPhee et al., 1989), dating from after the last interglacial. These faunas are cave and fissure accumulations of disarticulated bones of small terrestrial vertebrates, particularly rodents, birds, and lizards. In contrast, pre-Quaternary vertebrates of the Caribbean islands are particularly poorly known. For example, Jamaica, which has one of the most extensively studied fossil records in the region, has hitherto produced only three Tertiary vertebrates, all aquatic and hitherto known only from unique specimens. These include: the late Early Eocene sirenian Prorastomus sirenoides Owen, 1855, originally described on the basis of the skull, mandible, and atlas vertebra (for a recent discussion of this species, see Savage, 1977); the lower jaw of the early Middle Eocene crocodilian Charactosuchus kugleri Berg, 1969; and a fragment of needlefish jaw from the Pliocene (Caldwell, 1966). It is therefore significant to report the discovery of an early Middle Eocene sequence in which bones are not uncommon, including a bone bed that has produced a moderate diversity of aquatic (marine?) taxa.