TY - JOUR
T1 - Repeated mass strandings of Miocene marine mammals from Atacama Region of Chile point to sudden death at sea
AU - Pyenson, Nicholas D.
AU - Gutstein, Carolina S.
AU - Parham, James F.
AU - Le Roux, Jacobus P.
AU - Chavarría, Catalina Carreño
AU - Little, Holly
AU - Metallo, Adam
AU - Rossi, Vincent
AU - Valenzuela-Toro, Ana M.
AU - Velez-Juarbe, Jorge
AU - Santelli, Cara M.
AU - Rogers, David Rubilar
AU - Cozzuol, Mario A.
AU - Suárez, Mario E.
PY - 2014/2/26
Y1 - 2014/2/26
N2 - Marine mammal mass strandings have occurred for millions of years, but their origins defy singular explanations. Beyond human causes, mass strandings have been attributed to herding behaviour, large-scale oceanographic fronts and harmful algal blooms (HABs). Because algal toxins cause organ failure in marine mammals, HABs are the most common mass stranding agent with broad geographical and widespread taxonomic impact. Toxin-mediated mortalities in marine food webs have the potential to occur over geological timescales, but direct evidence for their antiquity has been lacking. Here, we describe an unusually dense accumulation of fossil marine vertebrates from Cerro Ballena, a Late Miocene locality in Atacama Region of Chile, preserving over 40 skeletons of rorqual whales, sperm whales, seals, aquatic sloths, walrus-whales and predatory bony fish. Marine mammal skeletons are distributed in four discrete horizons at the site, representing a recurring accumulation mechanism. Taphonomic analysis points to strong spatial focusing with a rapid death mechanism at sea, before being buried on a barrier-protected supratidal flat. In modern settings, HABs are the only known natural cause for such repeated, multispecies accumulations. This proposed agent suggests that upwelling zones elsewhere in the world should preserve fossil marine vertebrate accumulations in similar modes and densities.
AB - Marine mammal mass strandings have occurred for millions of years, but their origins defy singular explanations. Beyond human causes, mass strandings have been attributed to herding behaviour, large-scale oceanographic fronts and harmful algal blooms (HABs). Because algal toxins cause organ failure in marine mammals, HABs are the most common mass stranding agent with broad geographical and widespread taxonomic impact. Toxin-mediated mortalities in marine food webs have the potential to occur over geological timescales, but direct evidence for their antiquity has been lacking. Here, we describe an unusually dense accumulation of fossil marine vertebrates from Cerro Ballena, a Late Miocene locality in Atacama Region of Chile, preserving over 40 skeletons of rorqual whales, sperm whales, seals, aquatic sloths, walrus-whales and predatory bony fish. Marine mammal skeletons are distributed in four discrete horizons at the site, representing a recurring accumulation mechanism. Taphonomic analysis points to strong spatial focusing with a rapid death mechanism at sea, before being buried on a barrier-protected supratidal flat. In modern settings, HABs are the only known natural cause for such repeated, multispecies accumulations. This proposed agent suggests that upwelling zones elsewhere in the world should preserve fossil marine vertebrate accumulations in similar modes and densities.
KW - Fossil record
KW - Harmful algal blooms
KW - Strandings
KW - Taphonomy
UR - http://www.scopus.com/inward/record.url?scp=84896875470&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84896875470&partnerID=8YFLogxK
U2 - 10.1098/rspb.2013.3316
DO - 10.1098/rspb.2013.3316
M3 - Article
C2 - 24573855
AN - SCOPUS:84896875470
SN - 0962-8452
VL - 281
JO - Proceedings of the Royal Society B: Biological Sciences
JF - Proceedings of the Royal Society B: Biological Sciences
IS - 1781
M1 - 20133316
ER -