DOI: 10.5061/dryad.d0c28
title: Data from: New perspectives on transitions between ecological-evolutionary subunits in the "type interval" for Coordinated Stasis

description: Northern Appalachian Basin deposits and associated fossils have served as
 exemplars for ecological-evolutionary investigations, and as the reference
 interval for the concept of coordinated stasis. Here, we examine faunal
 and environmental changes within the uppermost Hamilton and lowermost
 Genesee Groups of the late Middle Devonian succession of New York State.
 Dramatic diversity loss, faunal migrations, and ecological restructuring
 recognized in these strata have been used previously to define the end of
 the Hamilton ecological-evolutionary subunit, and, furthermore, these
 strata and corresponding faunal changes represent the type region for the
 global Taghanic Biocrisis. We present and analyze a new, high-resolution
 data set of post-Taghanic Genesee fossil assemblages, in which we
 recognize 11 biofacies corresponding to an onshore-offshore (depth)
 gradient. The Genesee Fauna shows an unexpectedly high taxonomic
 similarity to nearshore biofacies of the pre-Taghanic Hamilton Fauna,
 related to the persistence of siliciclastic-dominated nearshore settings
 through the Taghanic Biocrisis, whereas the onset of anoxic/dysoxic
 conditions typified offshore portions of the environmental gradient. The
 “Nearshore Refugium Model” of Erwin offers a possible explanation for the
 persistence of taxa through the biocrisis in nearshore settings. This
 constriction was followed by subsequent expansion of these residual taxa
 to offshore environments in relatively similar associations, as increased
 Acadian orogenic activity and resultant delta progradation increased
 habitable space offshore by decreasing the extent of deeper-water,
 oxygen-poor settings. Although taxonomic similarity was high between the
 Hamilton and Genesee Faunas, biofacies structure differed primarily
 because of tectonically driven physical transformations to the basin and
 associated biotic turnover. Nevertheless, the combination of high
 taxonomic persistence of Hamilton nearshore taxa and the introduction of
 relatively few new taxa in the Genesee Fauna resulted in a taxonomic
 holdover that was much higher than observed in the original formulation of
 coordinated stasis.
description: Supplementary Table
 1All
 data used in this study have been added to the Paleobiology Database
 (http://paleodb.org; collections associated with References 28312, 29162,
 30118, 30119, and 30564). Data matrices analyzed can be found in
 Supplementary Tables 1 (Genesee Group bulk sampled data as absolute
 abundances) and 2 (Genesee and Hamilton groups bulk sampled data as rank
 abundances). See Read Me document for further details.Supplementary Table
 2All
 data used in this study have been added to the Paleobiology Database
 (http://paleodb.org; collections associated with References 28312, 29162,
 30118, 30119, and 30564). Data matrices analyzed can be found in
 Supplementary Tables 1 (Genesee Group bulk sampled data as absolute
 abundances) and 2 (Genesee and Hamilton groups bulk sampled data as rank
 abundances). See Read Me document for further details.