Temporal and spatial distribution of ostracodes across the Pennsylvanian–Permian boundary interval in eastern North America Neil E. Tibert a, ⁎, Michael C. Rygel b , Shelby C. Sanders a , Scott D. Elrick c , John Nelson c a Department of Earth & Environmental Sciences, University of Mary Washington, Fredericksburg, VA 22401, USA b Department of Geology, State University of New York, College at Potsdam, 44 Pierrepont Avenue, Potsdam, NY 13676, USA c Illinois State Geological Survey, 615 E. Peabody Dr., Champaign, IL 61820, USA abstract article info Article history: Received 8 May 2013 Received in revised form 22 July 2013 Accepted 6 August 2013 Available online 14 August 2013 Keywords: Ostracoda Pennsylvanian Permian North America Appalachian Ostracodes recovered from eastern North American coal measures in the Appalachian, Illinois, and Maritimes Basins have the potential to resolve the temporal and spatial relationships of the strata deposited during the Pennsylvanian–Permian boundary interval. The ostracode associations include: (1) a Pennsylvanian (Virgilian; Gzhelian) marine association dominated Hollinella cushmani with abundant brachiopods and foraminifera exclu- sive to the GIL 30 Core in Kentucky (Illinois Basin); (2) a latest Pennsylvanian (Virgilian; Gzhelian) brackish as- sociation dominated by Geisina upsoni (Kellet), Cavellina nebrascensis (Geintz), and Velatomorpha fittsi (Kellet) exclusive to the GIL 30 Core in Kentucky (Illinois Basin); and (3) an uppermost Permian (Asselian/Sakmarian) association of nonmarine taxa dominated by Whipplella cuneiformis (Holland), Whipplella parvula (Holland), Paleodarwinula hollandi (Scott), and Haworthina bulleta (Harris and Lalicker) that occurs in the uppermost conti- nental facies of both the Illinois and Dunkard Basins. A comparable nonmarine association of Paleodarwinula hollandi and Whipplella bretonensis (Copeland) occurs in the Bolsovian to Cantabrian (Moscovian to Kasimovian) coal measures of the Maritimes Basin of Atlantic Canada. The data presented herein provides new information about the withdrawal of marine waters from several major Late Paleozoic basins in eastern North America. Mid-continental marine influence persisted into the latest Pennsylvanian to earliest Permian during deposition in the eastern Illinois Basin on the western Appalachian coastal plain. The uppermost nonmarine association of nonmarine Ostracoda in both the Illinois Basin and Dunkard Basin indicates a synchronous development of aquatic freshwater faunas during Lower Permian times. With increasing geographic isolation of the eastern North American basins, the dispersal and radiation of Ostracoda in these basins was apparently facilitated by brood rearing as demonstrated by the dominance of the Platycopina and Darwinulocopina. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Eastern North America contains exceptionally preserved Upper Paleozoic ostracodes that track the marine faunal migration into the terrestrial aquatic waters of west-central Pangaea. From a paleoenvironmental perspective, this saltwater-to-freshwater transition was apparently gradual as Mississippian ostracode communities (Hoare and Mapes, 2000; Tibert and Scott, 1999; Williams et al., 2006) progressively gave way to the restricted marine and brackish faunas in the Pennsylvanian (Dewey, 1987; Tibert and Dewey, 2006). Ultimately, these faunas emerged as the fully nonmarine communities (terrestrial aquatic) that broadly correspond to the Pennsylvanian–Permian transition in the Appalachian Basin (Holland, 1934; Scott, 1944; Tibert et al., 2011). The timing of the withdrawal of the Carboniferous seas was complicated by the complex paleogeographical relationships between the North American basins (Fig. 1) that is confounded by the waning marine indicators preserved in the coal measures whereas plant macrofossils and palynomorphs have been the primary tool for regional correlation (Dimichele et al., 2011; Nelson et al., 2011; Zodrow and Cleal, 1985). In this paper, we demonstrate the utility of ostracodes to develop paleoenvironmental proxies that fall within the marine–brackish–freshwater spectrum with an objective to improve our understanding of the spatial and temporal relationships between the sedimentary basins deposited during the Pennsylvanian–Permian boundary interval. The most thoroughly studied stratigraphic intervals from North America include cyclothems that record the alternation between marine and nonmarine conditions. The Canadian Maritimes Basin, the most eastern depocenter on the western Atlantic conjugate mar- gin, saw the earliest marine withdrawal and subsequent freshwater transition with evidence for brackish and/or restricted marine condi- tions (Tibert and Dewey, 2006; Wightman, 1993; Wightman et al., 1993, 1994). The centrally located Appalachian Basin contains the last vestiges of Paleozoic sedimentary deposition in eastern North America. Deposits of the Dunkard Group are preserved in northern West Virgina, southeastern Ohio, and southwestern Pennsylvanian; these deposits contain exclusively nonmarine flora and fauna that International Journal of Coal Geology 119 (2013) 93–105 ⁎ Corresponding author. Tel.: +1 5406541423. E-mail address: ntibert@umw.edu (N.E. Tibert). 0166-5162/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.coal.2013.08.002 Contents lists available at ScienceDirect International Journal of Coal Geology journal homepage: www.elsevier.com/locate/ijcoalgeo