Data from: Two pulses of morphological diversification in Pacific pelagic fishes following the Cretaceous–Palaeogene mass extinction

Molecular phylogenies suggest some major radiations of open-ocean fish
clades occurred roughly coincident with the K/Pg boundary, however the
timing and nature of this diversification is poorly constrained. Here we
investigate evolutionary patterns in ray-finned fishes across the
Cretaceous-Palaeogene (K/Pg) Mass Extinction 66 million years ago (Ma),
using microfossils (isolated teeth) preserved in a South Pacific sediment
core spanning 72-43 Ma. Our record does not show significant turnover of
fish tooth morphotypes at the K/Pg boundary: only two of 48 Cretaceous
tooth morphotypes disappear at the event in the South Pacific, a rate no
different from background extinction. Capture-mark-recapture analysis
finds two pulses of origination in fish tooth morphotypes following the
mass extinction. The first pulse, at ~64 Ma, included short-lived teeth,
as well as forms that contribute to an expansion into novel morphospace. A
second pulse, centered at ~58 Ma, produced morphotype novelty in a
different region of morphospace from the first pulse, and contributed
significantly to Eocene tooth morphospace occupation. There was no
significant increase in origination rates or expansion into novel
morphospace during the early or middle Eocene, despite a near 10-fold
increase in tooth abundance during that interval. Our results suggest that
while the K/Pg event had a minor impact on fish diversity in terms of
extinction, the removal of the few dominant Cretaceous morphotypes
triggered a sequence of origination events allowing fishes to rapidly
diversify morphologically, setting the stage for exceptional levels of
ray-finned fish diversity in the Cenozoic.