Size differences of the post-anoxia, biotic recovery brachiopod, Dyoros sp., in Hughes Creek Shale (Carboniferous), Richardson County, Nebraska.

Daryl Johnson; Rex Hanger

doi:10.17307/wsc.v1i1.95

Autors/ores

Daryl Johnson Dept. of Geography & Geology University of Wisconsin-Whitewater
Rex Hanger Dept. of Geography & Geology University of Wisconsin-Whitewater

DOI:

https://doi.org/10.17307/wsc.v1i1.95

Resum

Two localities of the Carboniferous Hughes Creek Shale in southeastern Nebraska contain both fossiliferous limestones and shales, as well as black shales interpreted as being deposited under anoxic conditions in ancient oceans. Fossils within strata above the anoxic layers represent life that had recovered from a local killing event. Examining the killing/recovery patterns on expanded, regional scales is made difficult due to the relative lack of good exposures between outcrops. Previous miscorrelations have occurred for the Hughes Creek Shale in two established collecting localities separated by only a few kilometers. Specimens of the brachiopod fossil, Dyoros sp., abundant at both localities were compared using the size frequency distributions of their length measurements. Null hypotheses of the equality of the medians and equality of the overall distributions were not able to be rejected, adding support to the current accepted interpretation of correlation for the two localities, allowing for future use of both for examining killing/recovery of life on expanded geographic scale.

Referències

Des Marais, D., J. A. Nuth, III, L. Allamandola, A. P. Boss, J. D. Farmer, T. M. Hoehler, B. M. Jakosky, V. S. Meadows, A. Pohorille, B. Runnegar and A. M. Sporman. 2008. The NASA Astrobiology Roadmap. Astrobiology, 8(4): 715-730.

http://dx.doi.org/10.1089/ast.2008.0819

Hammer, O., Harper, D. A. T. and Ryan, P. D. 2001. PAST: Paleontological statistics software package for education and data analysis. Palaeontologica Electronica, 4(1): 1-9.

Holterhoff, P. and R. K. Pabian. 1990. Paleoenvironmental implications of a pyritized molluscan fauna from the Bennett Shale Member, Red Eagle Formation (Lower Permian), Richardson County, Nebraska. The Compass, 67(1): 35-46.

Humphries, S. 2007. Body size and suspension feeding, Pp. 16-32, In Hildrew, A., D. G. Raffaelli and R. Edmonds-Brown (eds.), Body Size: The Structure and Function of Aquatic Ecosystems. Cambridge University Press, Cambridge, England.

http://dx.doi.org/10.1017/CBO9780511611223.003