LOWER CARBONIFEROUS VERTEBRATE PROVINCIALITY IN THE ILLINOIS AND SOUTHERN APPALACHIAN BASINS

The Carboniferous vertebrate record has greatly improved in the last twenty years with the discovery of additional faunas in North America, Europe, and Australia.  These studies have broadened our understanding of the composition of Lower Carboniferous faunas and indicate previously unknown similarities among North American fresh- to brackish-water faunas, particularly in the Illinois Basin, but also in the southern Appalachian Basin.  These biogeographic patterns appear consistent across numerous vertebrate clades including tetrapods, dipnoans, and possibly rhizodonts and acanthodians.  In order to investigate biogeographic patterns among Carboniferous fresh to brackish water faunas we complied a data set of vertebrate taxa from 19 Carboniferous localities. Carboniferous localities from North America, Europe, and Australia were included and presence or absence of taxa from each locality was recorded at both the genus and family level.  Ordinations of both genus and family level data support the separation of faunas into European and North American groups.  Faunal provinciality within the Euramerican Carboniferous contradicts the hypothesis that during the Lower Carboniferous a single faunal province was present across Euramerica.  These patterns also indicate that Mississippian and Pennsylvanian vertebrate faunas are distinct entities and that several taxa are more common to either Lower or Upper Carbonifeorus faunas. Taxa indicative of a Lower Carboniferous North American Vertebrate Province include the tetrapod Greererpton and the dipnoan Tranodis.   These taxa are present in nearly every North American locality examined, but are absent outside the Illinois and Appalachian Basins.  Taxa common to European Lower Carboniferous faunas include baphetid tetrapods and the dipnoans Ctenodus and Sagenodus. Additional taxa, such as the acanthodian Gyracanthus, may contribute to this provinciality, however, taxonomic uncertainty of this genus prevents firm biogeographic conclusions.