Cave site contributions to vertebrate history

Abstract

Vertebrate fossils from cave deposits and karst features are recorded as early as the Mississippian with later occurrences of Permian vertebrates from fissures in Oklahoma, Triassic/Jurassic faunas from Wales and southwest England and Eocene to Oligocene faunas from France. Plio-Pleistocene cave fossil sites are numerous and are well known worldwide. The sheltered depositional environment in caves has facilitated the preservation of geochemical information such as stable isotope ratios and DNA in the bone assemblages. Bat colonies and owl roosts, common around cave entrances, contribute to the bone accumulation and provide a good sample of the local smaller vertebrate fauna. The use of caves by mammals as shelters, hibernation sites or dens for young, with the inevitable death in situ of some individuals, provides a unique sample so that growth series and predator-prey relationships can be studied. Caves in upland areas, where other environments of deposition are lacking, preserve a record of animals from those areas that are undergoing erosion. Age determination of cave deposits poses problems because they are isolated from marine or more widespread continental sequences. Correlation must be based on biological similarities, radiometric dates or palaeomagnetic data. Within-cave correlations are often difficult to define because of collapse, channeling and re-deposition. Access to the surface, with multiple openings at different times, may add further complications.