Fossilized Callixylon Wood

A magnified (400x) view of a sliver of Upper Devonian Period fossilized wood.  It is probably Callixylon found in the New Albany Shale of Clark County, Indiana.  While this area was a sea with anaerobic bottom, it is thought logs floated in from Pennsylvania or New York and sank.  Buried in the silt they fossilized instead of decomposing.


While trying to get a sample for the scanning electron microscope some very small thin pieces broke free.  They were transparent enough to use the optical microscope's bottom light thus able to achieve 400x magnification.  How to determine what material is represented by that optical pattern I am not sure.  I assume it is a fragment of two wood rays.

Last picture original fossil fragment originated from.  This piece differs from yesterday's fossil in that it is not coalified.

Thanks to Herb for the specimen.

Scanning Electron Microscope SEM - Callixylon

Recently, I found a a very small (7 mm x 3 mm) piece of coalified Callixylon wood from the Upper Devonian Period.  After searching a large pile of New Albany Shale in Clark County Indiana for a while, it was all I discovered.  A little disappointed, I left the site but later studied the specimen with an optical microscope.  To my surprise, it appeared the wood still had its ray lines intact.

After reading a section of Chapter 12 Progymnosperms in the book Paleobotany: The Biology and Evolution of Fossil Plants by Thomas Taylor, Edith Taylor and Michael Krings, I determined Callixylon wood rays are constructed of ray tracheids and ray parenchyma.  In figure 12.16 of the book displays a SEM image of pit membrane of tracheid and I wondered if such detail was still intact on one of these samples?

My microscope became ineffective after 100 times magnification to see something this small. What I needed was a scanning electron microscope (SEM).  Yikes! Those cost a lot of money and I am not a research university or million dollar company.  What to do?

Scanning Electron Microscope SEM

Image compliments of ASPEX Corporation

Fortunately, I remembered my friends at ASPEX Corporation in Pennsylvania who scanned a fossil for me earlier in the year.  They have a great FREE program that lets every day people get items imaged with a scanning electron microscope SEM.  The program is call "Send Us Your Sample".  Just follow these steps:

1) Go to the ASPEX Corporation website and print this form.

2) Fill out the form and mail it along with the sample to be scanned:

ASPEX Corporation
Free Sample Submissions
175 Sheffield Dr.
Delmont, PA 15626

 3) Once ASPEX completes the scan, the images will be posted on their website here.

Note: It should take about 2-6 weeks (depending on work load) for the results to post to the ASPEX website.  Submitters will be notified via e-mail.  Be sure to note on the submission form if you want the sample returned.

While at the ASPEX web site, check out their Name That Sample contest with a chance to win a brand new Netbook. 

Parmorthis waldronensis

This brachiopod fossil appears to be a Parmorthis waldronensis (Foerste) of the Waldron Shale.  Found in Clark County, Indiana from the Middle Silurian Period.

While the Louisville Limestone and Laurel Member layers represented a warm, shallow, opaque sea the material found in the Waldron Shale shows evidences of a muddy environment.  These fossils are a dark grey and preserved quite well in the shale.  They also have some pyrite crystals.

The Waldron Shale was named in 1882 by Dr. M. N. Elrod in the Geology of Decatur County, 12th Annual Report Indiana Department of Geological and Natural History 1882 (pp. 109-111).  Dr. James Hall described the Waldron Shale fauna in the 28th Report New York State Museum in 1879 (pp.100-199; plates 3-34).  Information gleaned from The Stratigraphic and Faunal Relations of the Waldron Fauna in Southern Indiana by E.M. Kindle and V.H.  Barnett (1909).

It is referred to as Orthis elegantula (Dalman, 1828) [pages 285-286; plate 21] in the Indiana Department of Geology and Natural History Eleventh Annual Report by John Collett (1881), The paleontology starts on page 215 and was written by Professor James Hall, State Geologist of New York. A similar brachiopod fossil found in New York's Rochester Shale is referred to as Resserella elegantula (Dalman, 1828) in The Silurian Experience Field ID Guide by Paul Chinnici and Kent Smith (2009).

Microscope image of the ridges of the brachiopod magnified 40 times.

 This specimen has a small pyrite crystal attached to its side.  Below is a microscope view 40x showing the crystal.

View of bottom of one of the specimens.

Thanks to the Indiana State Museum collections database web site for help with identification of these specimens.  This posts contains pictures of three different brachiopod fossils. I am only about 50% sure of this identification for all three. Some of the fossils could also be a Rhipidomella hybrida (Sowerby).