Geology and Zoology
Dr. Scott Ishman
This project is an extension of a Masters Degree thesis of a paleontology student, Tony Tobenski, who went to SIU (Tobenski, 2011). Tobenski (2011) examined the Menard Limestone of the Kinkaid Formation (Late Mississippian) to determine the function, morphology, evolution, and biostratigraphical usefulness of crinoid wing plates. I examined the Golconda and Glen Dean Formations of the Upper Mississippian Hombergian at the Golconda Marina (Type Section) in Illinois and in Western Kentucky near Cave-In-Rock, IL. Pterotocrinus is an extinct genus of crinoid (an echinoderm; related to starfish and sea urchins) and its wing plates are thought to be used for feeding or defense depending on the morphology of the plates. The goal is to test its biostratigraphic use by using the wing plates to show evolutionary changes in wing plate morphology and to possibly identify useful Pterotocrinus indices for the Golconda Formation. The Type Section had larger specimens while the Kentucky location had a higher diversity of species. Preservation bias and environmental conditions may have influenced species differences at the two localities.