Based on the dates of Tucker et al. (1998) the Frasnian is approximately 6 Ma in duration. Zircons from the Center Hill Ash Bed in the Chattanooga Shale, close to the Frasnian-Famennian boundary, are currently at Washington University for dating. This should lead to a more precise age for the Frasnian. There is some confusion in Tucker et al. (1998) about the ash bed dated from Little War Gap. The ash is identified as the Center Hill Ash, but the ash bed dated 380.8 Ma is the lowest ash in the Belpre Ash suite, which consists of six discrete ash beds at Little War Gap. The occurrence of Ancyrognathus barba in between ash 5 and ash 6 indicate MN Zone 8 (within Lower hassi Zone). The Center Hill Ash is present much higher in the Little War Gap section.

Graphic Correlation of Frasnian

Klapper (see Klapper , 1997) subdivided the Frasnian into 34.5 composite standard units (csu) using graphic correlation. Subdivision of the Frasnian using Pa. semichatovae and Pa. punctata will result in three substages of 22.1 csu (upper), 6.3 csu (middle), and 6.1 csu (lower), respectively.

Palmatolepis punctata

The holotype of Palmatolepis punctata is a specimen of Hinde (1879), collected from the Genesee Shale at North Evans, New York, along Eighteenmile Creek (reillustrated by Branson and Mehl, 1933; Ziegler, 1973). This is probably from the Rhinestreet Shale. Palmatolepis punctata has not been recovered with certainty from the Middlesex Shale; P. punctata is abundant in the basal Rhinestreet, and has been reported from the underlying Cashequa Shale. Specimens of P. punctata illustrated by Ulrich and Bassler (1926) and reillustrated by Huddle (1968) are from the basal Rhinestreet at Weyer (Shaleton), New York. The morphotype of the conodont used to define a substage boundary must be clearly defined, illustrated, and its occurrence well documented.

Taxonomic problems and range interpretations of key taxa need to be resolved before a final decision is reached.