Selective calcareous nannoplankton survivorship at the Cretaceous-Tertiary boundary

Calcareous nannoplankton underwent devastating diversity loss at the Cretaceous-Tertiary boundary (65.5 Ma), but recovered rapidly in the early Paleocene from a small number of survivor species. An understanding of this survivorship has been hampered by uncertainties introduced by reworking and mixing, but new high-resolution assemblage data from the northwest Pacific (Shatsky Rise, Ocean Drilling Program Site 1210) allow the unequivocal identification of 10 survivors. Evidence of shared adaptive strategies among these species provides the first indication that the extinctions were selective, with survival limited to a few neritic and/or opportunistic species, probably facilitated by hardiness and/or life-cycle escape strategies.