A PROPOSED REVISION OF NORTH AMERICAN SVALBARDIINID BRACHIOPODS

The genus Lissochonetes has been used as a wastebasket taxon, misapplied to a range of outwardly similar, small, smooth-valved chonetoid brachiopods of the subfamily Svalbardiinae, due to a poor understanding of internal features and development. Herein we propose a reclassification of Lissochonetes-like fossils based on newly collected material and archival specimens of upper Carboniferous and lower Permian age, from the North American Midcontinent region, including the Bend Arch area of Texas, and the Fort Worth, Illinois, Forest City, Arkoma and Appalachian Basins. We describe ten new genera and over thirty species, revise six of the eight previously known North American genera, and introduce a way to group genera based on hinge tooth morphology. These new taxa create an unbroken, relatively high-resolution biostratigraphic record for North American Svalbardiinae stretching from the faunal replacement event associated with Bashkirian glaciation through the end-Capitanian extinction. Also discussed are connections to local and global ecology, development, and potential evidence of mimicry in this widespread, but under-studied brachiopod group.