No CrossRef data available.
Article contents
Description and paleoecology of a population of Anthraconaia from the Pennsylvanian of southern Indiana
Published online by Cambridge University Press: 19 May 2016
Abstract
Anthraconaia sp. occurs in the thin nonmarine interval that lies between the Upper Millersburg Coal Member and the Lower Millersburg Coal Member (Pennsylvanian, Desmoinesian) in Warrick County, Indiana. Specimens of Anthraconaia sp. resemble Anthraconaia that occur in Pennsylvanian and Permian rocks of the Appalachian Basin, but they differ slightly in size, form ratios, or both. Specimens were found in massive, nonfissile gray mudstone; buff-colored, laminated limestone (ostracodal biomicrite, wackestone); and platy black shale. The only statistically significant variation between shells from these different lithologies is that shells recovered from the limestone tend to be more ovate than shells from the other two lithologies. This contradicts the findings of previous investigations in which more ovate Anthraconaia were found in the more organic-rich sediments of a given stratigraphic sequence. This difference is probably caused by the lack of discernible change in energy level through the depositional history of the interval and suggests that changing energy levels may be more important to the control of the morphology of Anthraconaia than the level of organic carbon in the sediment.
- Type
- Research Article
- Information
- Copyright
- Copyright © The Paleontological Society