10.5061/DRYAD.38537
Sibert, Elizabeth
Harvard University
Norris, Richard
Scripps Institution of Oceanography
Cuevas, Jose M.
University of San Diego
Graves, Lana G.
University of California, San Diego
Cuevas, Jose
University of San Diego
Data from: Eighty-five million years of Pacific Ocean gyre ecosystem
structure: long-term stability marked by punctuated change
Dryad
dataset
2016
Paleogene
Neogene
Fish Evolution
paleoceanography
Paleocene
Eocene
pelagic ecosystem evolution
Cretaceous and Cenozoic
fish teeth
elasmobranchs
Oligocene
Ichthyoliths
Maastrichtian
dermal denticles
Miocene
Micropaleontology
2016-04-21T14:59:02Z
2016-04-21T14:59:02Z
en
https://doi.org/10.1098/rspb.2016.0189
87971 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
While the history of taxonomic diversification in open ocean lineages of
ray-finned fish and elasmobranchs is increasingly known, the evolution of
their roles within the open ocean ecosystem remains poorly understood. To
assess the relative importance of these groups through time, we measured
the accumulation rate of microfossil fish teeth and elasmobranch dermal
denticles (ichthyoliths) in deep-sea sediment cores from the North and
South Pacific gyres over the past 85 million years (Myr). We find three
distinct and stable open ocean ecosystem structures, each defined by the
relative and absolute abundance of elasmobranch and ray-finned fish
remains. The Cretaceous Ocean (pre-66 Ma) was characterized by abundant
elasmobranch denticles, but low abundances of fish teeth. The Palaeogene
Ocean (66–20 Ma), initiated by the Cretaceous/Palaeogene mass extinction,
had nearly four times the abundance of fish teeth compared with
elasmobranch denticles. This Palaeogene Ocean structure remained stable
during the Eocene greenhouse (50 Ma) and the Eocene–Oligocene glaciation
(34 Ma), despite large changes in the overall accumulation of both groups
during those intervals, suggesting that climate change is not a primary
driver of ecosystem structure. Dermal denticles virtually disappeared from
open ocean ichthyolith assemblages approximately 20 Ma, while fish tooth
accumulation increased dramatically in variability, marking the beginning
of the Modern Ocean. Together, these results suggest that open ocean fish
community structure is stable on long timescales, independent of total
production and climate change. The timing of the abrupt transitions
between these states suggests that the transitions may be due to
interactions with other, non-preserved pelagic consumer groups.
Ichthyolith Counts for DSDP Site 596 and ODP Site 886IODP Sample
identifiers, downcore depth, age, ichthyolith counts and ichthyolith
accumulation rates for DSDP Site 596 and ODP Site
886.Sibert_etal_Datasets.xlsx
Pacific Ocean