As part of the run up to ESCONI's 70th Anniversary, here is Flashback Friday post #19. If you have pictures or stories to contribute, please send them over to [email protected]. Thanks!
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Jack Wittry gave a lecture entitled "Antediluvian Phytology" on Friday, September 11th, 2009. It was about the Mazon Creek fossil flora. The definitive reference book on the subject, The Mazon Creek Fossil Flora, had been published a few years prior in 2006. That book was authored by Jack and published by ESCONI. This lecture summarized much of the information in the book. Since then, an animal book called "The Mazon Creek Fossil Fauna" was published in 2012 and was also authored by Jack. Currently, an updated fossil flora book entitled "A Comprehensive Guide to the Fossil Flora of Mazon Creek" will be published later this year. These books represent years of work and are essential to understanding the Mazon Creek fossil biota. Congratulations, Jack! We are all excited to see this essential addition to a Mazon Creek collector's library!
There was certainly a back-to-school atmosphere at the General Meeting last Friday, with attending members full of stories and finds after the club’s summer recess. As people paraded into the classroom, many had cardboard trays, specimen cases or plastic bags carrying carefully split fossil concretions pertaining to that evening’s lecture topic. After some special announcements, Jack Wittry, author of the beautiful and informative book entitled, The Mazon Creek Fossil Flora, presented a standing-room only talk on his specialty. Not only was his delivery and organization clear – making sense of the, often time, fragmented evidence of the fossil record – but he cleverly introduced his hypothesis of events in the area with published material from over 150 years ago.
Edmund Tyrell Artis titled his first printed and illustrated treatment of prehistoric flora, Antediluvian Phytology, with an obvious Biblical reference meaning, “before the flood.” As all Mazon Creek enthusiasts know, it is the classic scenario of rapid burial that has brought us the splendid phenomenon and preservations within siderite concretions. It has been supposed from early on that nodules existing under many layers of chemically consistent sediment – in places, 60 feet of it – indicate a dramatic, one might say, cataclysmic event.
Reconstruction of prehistoric plants and ecosystems is a puzzle game of many pieces. Mr. Wittry methodically and comprehensibly brought the captive audience through the six general groups of plant life found in the fossil record of Mazon Creek, a Pennsylvanian Period landscape. Sometimes disparate parts of a single plant species can be assigned to entirely different genera by form, and some remain in basket categories with no biologicallyspecific assignment at all. It took Mr. Wittry to help this student of fossil flora to fully understand the leaf- (seed)-bark-root relationships, establishing a more certain diversity in each of the “form-taxa,” as well as the relative distribution of these plants and their heights, in wetter or drier climes.
North central Illinois was nearly equatorial 300 million-years ago, plus or minus about ten degrees. Bordered by shallow brackish bays and river systems, the swamps and forests lived in longer years and over shorter days, with an oxygen content nearly 50% greater than it is today. By the evidence of deeply laid silt (now shale), and the preservation of sometimes complete vertical trunks of scale trees, we can begin to comprehend the enormity of the flooding event of that time. For the fact that some true fern species were represented in the fossil record almost entirely in a fertile form, and others were not at all, seems to indicate a relatively thin slice of time in the course of the plants’ destruction, redistribution and burial. Mr. Wittry theorized that it must have been a matter of weeks, not months or years, and the fossil record a virtual “snapshot” of life at that time. And, just as remarkably, we now know that the age of this momentous occurrence is 307 million years.
After the lecture, the audience had numerous questions to which Mr. Wittry gave careful attention. Many of the visitors brought their own Mazon Creek discoveries, seeking expert identification for the species, as well as validation, I suppose, as a true participant in this bounty of information and beautiful preservations. I felt a sense of privilege among the exhibitors and storytellers, those of us who jockey and lift ourselves to gaze into that window of Illinois so many years ago, and the consequence of a flood in that time of near-biblical proportions.
To see more images from the General Meeting, or new pictures from Lonestar Quarry (2008) go to Photo Albums in the left column of the ESCONI website, www.esconi.org.
