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

Abstract

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.

Stratigraphic and environmental control on marine benthic community change through the early Toarcian extinction event (Iberian Range, Spain)

“…The same species (i.e., with the same environmental tolerance), persisted longer at Sierra Palomera because of the shallower water depth compared to Castrovido. This further confirms the need to study multiple sections in the same sedimentary basin, along an onshore-offshore transect in order to better understand the timing and magnitude of an extinction event (Smith et al 2001;Holland 2015;Danise and Holland 2017).…”

Pliocene stratigraphic paleobiology in Tuscany and the fossil record of marine megafauna

“…Published studies that have taken this direction are still not many, examples concerning Jurassic ichthyosaurs, plesiosaurs and pliosaurs (McMullen et al, 2014), Cretaceous turtles, plesiosaurs, bony fish and sharks (Schmeisser McKean and Gillette, 2015), Eocene archaeocetes, sea cows and sharks (Peters et al, 2009), and Neogene marine mammals and sharks . All of these papers record the cooccurrence of shelly faunas, only one undertaking quantitative studies of the distribution of fossil invertebrates (Jurassic of the Sundance Formation: McMullen et al, 2014, see also Danise and Holland, 2017). The benefits of an outcrop-scale sequence stratigraphic approach include: (1) an independent record of relative sea-level change to test paleobiological hypotheses (see also Pyenson and Lindberg, 2011;Noakes et al, 2013); (2) a chronostratigraphic scheme for high-resolution correlations; (3) a means to recognise minor and major breaks of the record; (4) an ecological and sedimentary framework for taphofacies distribution (Patzkowsky and Holland, 2012); and (5) an independent control of onshore-offshore patterns of fossil assemblages (e.g., Tomašových et al, 2014).…”

Tidal dynamics in palaeo-seas in response to changes in bathymetry, tidal forcing, and bed shear stress

“…1), also known as the proto-Western Interior Seaway (Blakey, 2014), developed in a retroarc foreland basin (Brenner & Peterson, 1994;Bjerrum & Dorsey 1995) that covered an area spanning between today's British Columbia, where it was connected to the Pacific Ocean at ~55-60°N/63-65°W, and today's Wyoming to the SE (Imlay, 1952;Imlay, 1980;Blakey, 2014). During the Callovian and Oxfordian Stages, the Sundance Sea periodically extended an additional ~1500 km south-westward (Imlay, 1952;Pipiringos & O'Sullivan, 1978;Peterson & Pipiringos, 1979;Imlay, 1980;Kreisa & Moila, 1986;Caputo & Pryor, 1991;Anderson & Lucas, 1994;Brenner & Peterson, 1994;Peterson, 1994;Wilcox & Curie, 2008; Hintze & Kowallis, 2009;Sprinkel et al, 2011;Thorman, 2011;Doelling et al, 2013;Danise & Holland, 2017Zuchuat et al, 2018;2019a;Danise et al, 2020), flooding the SSW-NNE-oriented retroarc foreland basin known as the Utah-Idaho Trough (Bjerrum & Dorsey, 1995), which developed at the foot of the Elko Orogeny (Thorman, 2011;Anderson, 2015). These repeated southwestward, multi-storey incursions (Zuchuat et al, 2019a) from the Sundance Sea led to the deposition of two shallow-marine sedimentary units that crop out today in east-central Utah: The Callovian Carmel Formation and the Oxfordian Curtis Formation.…”

“…This paper will focus on the development of the lower Curtis only. B) Schematic panel displaying the part of the Middle and Upper Jurassic lithostratigraphy outcropping between Central Utah and Wyoming (after Doelling et al, 2013;Danise & Holland, 2017;Zuchuat et al, 2018;Danise et al, 2020). Note that the J-3 and the J-5 Unconformities are not regarded as unconformities sensu stricto anymore, but rather as a highly diachronous transgressive surface (Zuchuat et al, 2019a), and the product of a prograding braided fluvio-deltaic system unimpacted by relative sea-level fall (Danise et al, 2020), respectively.…”

“…The lack of high-resolution biostratigraphy and absolute dating of Curtis-Summerville interval makes precise regional correlation between units in the Curtis Sea and Sundance Sea challenging. Nevertheless, as the Oxfordian regression of the Curtis Sea persisted and the climate became more humid (Demko et al, 2004;Boucot et al, 2013;Danise & Holland, 2017), the shoreline developed as a tide-dominated deltaic system (Holland & Wright, 2020). These sandstone-dominated strata, which belong to the Windy Hill Member of the Morrison Formation (Pipiringos, 1968), indicate that tidal currents lingered despite a shrinking sea (Uhlir et al, 1988;Danise & Holland, 2018;Holland & Wright, 2020).…”