Taphonomic Implications of a Crinoid from Echinoderm-Poor Lithofacies in the Upper Ordovician (Katian: Cincinnatian) of Northern Kentucky

James R. Thomka, Thomas J. Malgieri, Kailyn M. Popovich-Martin, Carlton E. Brett

Abstract


Crinoids (Phylum Echinodermata) represent major components of fossil assemblages in the type Cincinnatian (Upper Ordovician: Katian) of the greater Cincinnati Arch region. However, certain shallow marine lithofacies are characterized by a nonexistent to depauperate crinoid fauna, being instead dominated by trilobites, bryozoans, mollusks, and in some layers solenoporid algae? and stromatoporoids. One such setting is represented by the Grant Lake Formation, equivalent to the upper Corryville and Mount Auburn members of the McMillan Formation of Ohio, as exposed south of Flemingsburg, Fleming County, northern Kentucky. Described herein is an articulated crinoid crown (Anomalocrinus?) from this otherwise crinoid-poor interval. This occurrence may reflect either (1) a brief interval where conditions were more amenable to occupation by crinoids, possibly corresponding to a minor flooding surface, or (2) transportation of skeletal remains from nearby, deeper offshore areas that contained crinoids in greater abundance. The second interpretation seems more likely given the absence of in situ attachment structures and rarity of disarticulated column material at the study site. This study illustrates the value of echinoderm remains in paleoenvironmental analysis, the significance of crinoidal material in taphonomic interpretation of Paleozoic argillaceous carbonate deposits, and the sensitivity of crinoid fossils as indicators of allochthony or autochthony.


Keywords


Maysvillian; Grant Lake Formation; fossil transport; Anomalocrinus

Full Text:

PDF


DOI: http://dx.doi.org/10.18061/ojs.v120i2.6976

Refbacks

  • There are currently no refbacks.


Copyright (c) 2020 James R. Thomka, Thomas J. Malgieri, Kailyn M. Popovich-Martin, Carlton E. Brett

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

 

 


Visit The Ohio Academy of Science's webpage

Visit our Knowledge Bank site for articles published from 1900 through 2013.

The Ohio Journal of Science is published by The Ohio State University Libraries in partnership with The Ohio Academy of Science.

If you encounter problems with the site or have comments to offer, including any access difficulty due to incompatibility with adaptive technology, please contact libkbhelp@lists.osu.edu.

ISSN: 2471-9390 (Online); 0030-0950 (Print)