Data from: No deep diving: evidence of predation on epipelagic fish for a stem beaked whale from the late Miocene of Peru

Although modern beaked whales (Ziphiidae) are known to be highly
specialized toothed whales that predominantly feed at great depths upon
benthic and benthopelagic prey, only limited palaeontological data
document this major ecological shift. We report on a ziphiid–fish
assemblage from the Late Miocene of Peru that we interpret as the first
direct evidence of a predator–prey relationship between a ziphiid and
epipelagic fish. Preserved in a dolomite concretion, a skeleton of the
stem ziphiid Messapicetus gregarius was discovered together with numerous
skeletons of a clupeiform fish closely related to the epipelagic extant
Pacific sardine (Sardinops sagax). Based on the position of fish
individuals along the head and chest regions of the ziphiid, the lack of
digestion marks on fish remains and the homogeneous size of individuals,
we propose that this assemblage results from the death of the whale
(possibly via toxin poisoning) shortly after the capture of prey from a
single school. Together with morphological data and the frequent discovery
of fossil crown ziphiids in deep-sea deposits, this exceptional record
supports the hypothesis that only more derived ziphiids were regular deep
divers and that the extinction of epipelagic forms may coincide with the
radiation of true dolphins.