First Highly Stratified Prehistoric Vertebrate Sequence from the Galapagos Islands, Ecuador

Abstract

We report an assemblage of ca. 6900 vertebrate fossils from a preliminary excavation at Barn Owl Cave, Isla Floreana, Galapagos Islands, Ecuador. Age of this stratified deposit ranges from historic times (less than 200 yr old) to the early Holocene (at least 8290 ± 70 radiocarbon years B.P., which equals 7485-7055 B.C.). Five of the 11 indigenous species identified thus far from the bone assemblage no longer occur on Floreana. Their extirpation is due to human influence over the past two centuries. The sedimentary and faunal compositions of the Barn Owl Cave bone deposit may reflect paleoclimatic changes, with relatively wet intervals indicated by darker, more clayey sediments and a relative scarcity of bones of the Floreana lava lizard (Micro/aphis grayii). Further excavation at Barn Owl Cave is likely to yield insights into the timing and extent of late Quaternary climatic and faunal changes in the Galapagos Islands.