DOCUMENTATION OF THE FLORAL ASSEMBLAGE AND PALEOENVIRONMENT, LOWER RHODE ISLAND FORMATION OF THE NARRAGANSETT BASIN FROM A FOSSIL LOCALITY IN NORTH ATTLEBORO, MASSACHUSETTS

The Narragansett Basin, in southeastern Massachusetts and Rhode Island, represents an intermontane rift basin that contains a thick sequence of nonmarine sediments (Lyons & Sproule, 2018; Shaler, et al., 1899). The basin sediment section has been subdivided into five formations, the thickest of which is the Rhode Island Formation. Here we present our results of a detailed study of a single locality in the lower part of the Rhode Island formation herein called the Attleboro Fossil Pit (“AFP”). The locality exposes a 15 meter wide and 1 meter high series of tilted, thinly bedded black shales. The lower part of the section contains richly fossiliferous thinly bedded black shale that grades up-section into more fissile thin sheets of nonfossiliferous black shale. We have systematically collected and identified fossils from a one meter section in the lower part of the exposure that contains a series of easily recognizable bedding surfaces (around 15 in total). These bedding surfaces contain a rich floral assemblage that we have tentatively identified as mostly branch segments of Calamites, whole and partial pinnules from three species of Neuropteris ferns, some large leaves of Macroneuropteris macrophylla, whorled leaves from Sphenophyllum, and small Cyclopteris pinnules that are indicative of a typical Pennsylvanian paludal environment consistent with other previously studied localities (Knecht, et al., 2024; Getty, et al., 2017; Emma, 2017 for example). Up until this point we have yet to document any evidence of trace or body fossils of vertebrates or insects that have been described elsewhere (Getty, et al., 2017).