Data from: Faunal response to sea-level and climate change in a short-lived seaway: Jurassic of the Western Interior, USA

Understanding how regional ecosystems respond to sea-level and
environmental perturbations is a main challenge in palaeoecology. Here we
use quantitative abundance estimates, integrated within a sequence
stratigraphic and environmental framework, to reconstruct benthic
community changes through the 13 myr history of the Jurassic Sundance
Seaway in the western United States. Sundance Seaway communities are
notable for their low richness and high dominance relative to most areas
globally in the Jurassic, and this probably reflects steep temperature and
salinity gradients along the 2000 km length of the Seaway that hindered
colonization of species from the open ocean. Ordination of samples shows a
main turnover event at the Middle–Upper Jurassic transition, which
coincided with a shift from carbonate to siliciclastic depositional
systems in the Seaway, probably initiated by northward drift from
subtropical latitudes to more humid temperate latitudes, and possibly
global cooling. Turnover was not uniform across the onshore–offshore
gradient, but was higher in offshore environments. The higher resilience
of onshore communities to third-order sea-level fluctuations and to the
change from a carbonate to a siliciclastic system was driven by a few
abundant eurytopic species that persisted from the opening to the closing
of the Seaway. Lower stability in offshore facies was instead controlled
by the presence of more volatile stenotopic species. Such increased
onshore stability in community composition contrasts with the
well-documented onshore increase in taxonomic turnover rates, and this
study underscores how ecological analyses of relative abundance may
contrast with taxonomically based analyses. We also demonstrate the
importance of a stratigraphic palaeobiological approach to reconstructing
the links between environmental and faunal gradients, and how their
evolution through time produces local stratigraphic changes in community
composition.