PTEROTOCRINUS WING PLATE MORPHOLOGY IN THE HOMBERGIAN

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

Electrochemistry of potential bioreductive alkylating quinones : Part 2. Electrochemical properties of 2,5-bis(1-aziridinyl)-3,6-bis(ethoxycarbonylamino)-1,4-benzoquinone and some model compounds

The reduction mechanism of 2,5-bis(1-aziridinyl)-3,6-bis(ethoxycarbonylamino)-1,4-benzoquinone (Diaziquone, AZQ) and several model compounds of the mono- and bis(1-aziridinyl)quinone type at the dropping mercury electrode in aqueous solutions was studied. In addition, the influence of methyl substitution of the aziridinyl moiety at the 2-position on the protonation of the aziridine nitrogen was investigated. Substituent effects on quinone reduction and aziridine protonation prior to and following quinone reduction were studied qualitatively

Electrochemistry of potentially bioreductive alkylating quinones : Part 1. Electrochemical properties of relatively simple quinones, as model compounds of mitomycin- and aziridinylquinone-type antitumour agents

The influence of methyl-, hydroxy and amino substituents on the electrochemical behaviour of simple 1,4-naphtho-and 1,4-benzoquinones, model compounds of many quinoid antitumour agents, in aqueous media was studied. Significant changes in electrochemical behaviour were observed, potentially the result of a change in the electron density of the quinone moiety, pre- or post-protonation of substituents, hydrogen bond formation, tautomerization reactions and steric interactions between the quinone moiety and substituents. The information obtained was of benefit in the elucidation of the reduction mechanisms of quinoid antitumour agents such as aziridnylquinones and mitomycins