Whales in the Desert

Abstract

Paleontology![Figure][1] CREDIT: ADAM METALLO/SMITHSONIAN INSTITUTION Mass strandings of whales have long puzzled observers, who wonder about the causes of such simultaneous and often large-scale mortality events. These events are not new, however, and recent road development in the Atacama region of Chile serendipitously revealed a large and unique collection of marine vertebrate fossils that may shed some light on the phenomenon. Pyenson et al. report that the site, Cerro Ballena, dates to the Late Miocene period and consists of over 40 skeletons of marine vertebrates, including rorqual and sperm whales, seals, predatory fishes, and fascinating, now completely extinct, species such as walrus-whales and aquatic sloths. Four distinct time horizons exist within the site, indicating that the mass strandings occurred repeatedly, and the relatively complete condition of the skeletons suggests that the death site was protected from scavengers and other forces that would distribute the bones. Based on the diverse array of species involved, and the repeated occurrence of the strandings, harmful algal blooms may have been to blame. The assemblage at Cerro Ballena provides both a vivid picture of a rich but now past marine environment and insight into a phenomenon that is often still a mystery. An associated open-access Web site allows readers to learn more about the site and fossils. Proc. R. Soc. London Ser. B 281 , 20133316 (2014). [1]: pending:yes