Also known as Was: Stereoaster-Brockocystis Association of the Brassfield Formation of Ohio

Where: Greene County, Ohio (39.8° N, 83.0° W: paleocoordinates 25.5° S, 52.7° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Brassfield Formation, Llandovery (443.4 - 433.4 Ma)

• The Brassfield Formation of Ohio was considered by Rexroad (1967) on the basis of rather sparse conodont evidence to be either late early, or middle Llandoverian. According to Nicoll & Rexroad (1968) the Brassfield, aside from the Lee Creek Member and Belfast Member (where present), is in their Icriodina irregularis condonont assemblage Zone in their study area, including the sites of Rexroad (1967). It should be noted that Foerste (1885) recorded Microcardinalia triplesiana from the Soldiers Home site (locality 6 of Ausich, 1986b); this occurrence has been confirmed (Rexroad et al., 1965; Boucot &Ehlers, 1963), and suggested a late Llandoverian (C4-C5) age to Rexroad et al. (1965). Microcardinalia triplesiana is now regarded as a good zonal indicator of approcimately C1-C2 age (Carlson & Boucot, 1970; Berry & Boucot, 1970). Triplesia has also been cited from the Brassgield in the Dayton, Ohio vicinity (Berry & Boucot, 1970), suggesting that the Brassfield in this area is a typical example of a Microcardinalia Zone fauna, i.e., C1-C2.

• formation-level stratigraphic resolution

Environment/lithology: reef, buildup or bioherm; lithified reef rocks

Size class: macrofossils

Primary reference: T. J. Frest, C. E. Brett, and B. J. Witzke. 1999. Caradocian-Gedinnian echinoderm associations of Central and Eastern North America. Paleocommunities--a case study from the Silurian and Lower Devonian 638-783 [M. Foote/K. Koverman/P. Wagner]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 13337: authorized by Michael Foote, entered by Kimberly Koverman on 28.02.2002

Creative Commons license: CC BY (attribution)