A NEW LATE MISSISSIPPIAN GONIATITE FAUNA FROM NORTH-CENTRAL ARKANSAS

A new fauna of Late Mississippian (Chesterian) ammonoids has been recovered from the Fayetteville Shale in north-central Arkansas. The assemblage was collected from the lower member of the Fayetteville Shale near the community of Leslie in Searcy County . The strata is composed of laterally continuous black shales considered to be of deep marine origin formed during the submergence of the Chesterian marine transgression.

Goniatite faunas have been recovered previously from the lower member of the Fayetteville Shale; however, collections were mainly comprised of small immature individuals whose identification was problematic. The Leslie fauna consists of numerous exceptionally well preserved, pyritized goniatites ranging in size from roughly five millimeters to greater than 50 millimeters. The fauna is dominated by representatives of Lusitanites subcircularis (S. A. Miller) and Neoglyphioceras crebriliratum Gordon. The fauna is similar in nature to faunas recovered from the Hindsville Limestone (Mississippian - Chesterian) below the lower member of the Fayetteville Shale in western Arkansas. The fauna supports correlation of the lowermost portion of the Fayetteville Shale and the Hindsville Limestone to the late Visean (P₂) of the Standard European Carboniferous succession.