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).

Megistocrinus rugosus Calyx

Megistocrinus rugosus crinoid calyx drawings seen in Plate 38 of Contribution to Indiana Palaeontology Volume I Part I to XX by George K. Greene.  [Side note: When George Greene died in 1916 his collection of over 400,000 specimens was shipped to the American Museum in New York by train.]  The crinoids are described as being found in the Upper Devonian beds at the Falls of the Ohio.

The pictures with blue backgrounds are of a fossil fragment I found in the Jeffersonville Limestone of Clark County, Indiana. It appears to be the base of a crinoid calyx Megistocrinus rugosus. Note how wrinkled its surface is. The last image is of the inside of the cup. The fossil is from the Middle Devonian Period.  Thanks to Alan for the identification.