E.S.C.O.N.I.

       PALEONTOLOGY STUDY GROUP MEETING

                                January 18, 2003

Chairman John Good called the meeting to order and introductions were made.  Dorothy Auler is Hostess and provided materials for the silent auction.  Bryan Nugent had books for sale also.

                        Future Paleontology Group Meetings

 John reminded the group about Burpee PaleoFest February 22 and 23 in Rockford.  We may have a table where we can distribute flyers and club info.  The program is on their web site and linked from our web site.  Our March Show is March 1 and 2 and Paleo should have 2 cases, one may be unusual animals of Mazon Creek and the other may be Lone Star if we can get enough material together.  Let John know what you can put in the group’s cases.  MAPS (cephalopods and ammonites) will be March 28-30 in Macomb and John hopes to have the geode hunting trip included the same as last year.  The next tentative field trip will be to Braceville on March 22 and 23, which is the same weekend as the Lizzadro Mazon trip (to be hosted by our Jim Fairchild).  He is still working on joint field trips with Minnesota club.  A trip to New Jersey, Pittsburgh Museum and Red Hill (Pennsylvania) may be April 26 and 27.  Wednesday January 22 is a talk by Jack Horner at IMSA (Illinois Math and Science Academy) in Aurora and costs $10.  Member Rob Sula reminded all that he is running field trips with Paleo Prospectors in South Dakota, Montana and Nebraska.  Check with him for details.  Also Mark Renz (friend of Rob Sula) in Florida has a great new site with mammoths and mastodons.  Membership dues are due.  John then introduced member Tom Williams who made a presentation.

                      Crinoid Dig in Alabama

 Tom introduced a unique site in the southern US.  There are three subgroups of crinoids found here – Inaduata, Flexibilia and Camerata.  There are no big camerates or inaduates, but there are large flexibles – which were the most dominant though not the most abundant.  The camerates had lots of plates and big arms.  The most common flexible at this site is Onychocrinus found along with very small Taxocrinus.  In the Mississippian period there were about 800 genera of crinoid known that were mostly filter feeders that liked normal salt water marine conditions.  Outside of these conditions they were not found.  Most of the Midwest was shallow marine at this time with lots of crinoids found.  As the continents were separating there were areas of volcanic activity in the Ordovician in the Carolinas.  The ash in these areas is being studied to help learn more about the extinctions they cause. 

 Crinoids came around in the Cambrian with large numbers in the Ordovician, went nuts in the Mississippian, and then began to decline.  The only group that made it out of the Paleozoic were the Inaduates and they then died out in the Triassic.  Most crinoids died out at the end of the Permian.  It might have been caused by a change in the salt water by glaciation along with the change in sea level.  Active loading and unloading along the Appalachians affected sea life.  This deposit at the site is a barrier island deposit in quartz sandstone that is very resistant.  The crinoids were outside the bar in the open ocean or offshore environment.  There are all 3 tiers of assemblage found at this site at different depths- upper, middle and lower.  Platycrinites is not found at this site.  Substrate chemistry can affect what is living there.  Acrocrinus is the largest camerate found at this site.  It is extremely fragile and is rarely found intact.  Zeacrinites is fairly common and is more primitive and probably lived near the bottom.  Phanocrinus is the most common crinoid at the site and ranged in size.  A couple of Pentaramicrinus were found.  An inaduate Ropacrinus was fragile and rare; only a few were found.  Filiacrinus had a cone shaped cup and is fairly common in the area; this may be a link to the modern crinoids.  Another camerate Dichocrinus was fairly common in the lower Mississippian and is small (an inch or two), living on the surface.  Among the flexibles, Taxacrinus was small (compared to the big ones found at Crawfordsville).  Onychocrinus was a large robust crinoid and could have very long stems.  Often the head is gone on downstream and is not found. 

 The site is in the Appalachians of Alabama.  Sometimes these crinioids are found in limestone interbedded with shale.  You need caprock over them to keep the water from getting in and destroying the fossils.  They dug down about 5-6 feet.  There were 2-6 inches of black mud over the crinoid layer.  It may have been caused by a storm event.  Some of the crinoids are cut right in half, but they were living that way.  Wendy Taylor was on this dig.  Glue was used to help hold them apart to protect them from water.  Larry Osterberger was along and helped to trace the stems to the heads of the fossils.  After the glue they used epoxy and fiberglass across them on some of the fossils.  They used a large rock saw to cut up blocks around the fossils.  One large section had stems on them 6 feet long.  There were only a couple of holdfasts found during the first dig 1995, but none in 1998.  He showed many slides of the fossils as they were dug out. 

 Tom then answered questions from the group.  They got many plates out.  The largest is about 3 by 5 feet and has about 100 crinoids on it (it is at PRI now).  The site is on private property in Northern Alabama and has no more fossils there to find.  The first fossil was found there by John Catalani.  There were a lot of Archimedes found there, but they were hard to get with their fronds (he did have a fossil with fronds to show us).  Many times you find crinoids that have been transported.  Here they are attached to stems indicating that they lived here.  Some were still living on broken stems.  There were some starfish found here also.  There was a brittle star found on a crinoid.  They are not all aligned in the same direction as would happen with wave action.  This may strengthen the single burial event explanation.  The heavy mud would have choked them off as they prefer cleaner water.  They were found in the Chester Formation of the Upper Mississippian.  Phanocrinus was a common and tough crinoid which could regenerate broken arms and which may have given rise to others.  He had many fossils from the dig and from other sites including Phacelocrinus, Fifeocrinus, Culmicrinus, Phanocrinus, Archimedes, Zeacrinites, and Onychocrinus. 

 The meeting was adjourned for refreshments and the silent auction.

Respectfully submitted                Karen Nordquist, Secretary 

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