Spinocyrtia (Platyrachella) oweni Brachiopod Fossil

This brachiopod fossil was found in the Silver Creek Member of the North Vernon Limestone of Clark County, Indiana, USA. It appears to be a Spinocyrtia (Platyrachella) oweni. It existed in the Middle Devonian Period.

Fossil was cleaned with ultrasonic cleaner.

Heliophyllum infundibulum Horn Coral with Aulocystis

A fine Middle Devonian fossil specimen of a Heliophyllum infundibulum horn coral hosting another coral colony of Aulocystis transitorius. I found this coral in the Beechwood Member, North Vernon Limestone, Givetian Stage of Clark County, Indiana, USA and my cousin Kenny cleaned it with air abrasion. It looks so much different when I spotted it. One could tell it was a horn coral and had another coral colony but WOW he really uncovered a nice size colony on this specimen.

Thanks to Kenny for the pictures.

Protoleptostrophia perplana? Brachiopod

This may be one of the largest best preserved brachiopods I have ever found, measuring over 5 cm in width. It was recovered from the Silver Creek Member of the North Vernon Limestone of Clark County, Indiana, USA and appears to be a Protoleptostrophia perplana? (Conrad, 1839). Originally, I thought this was a Megastrophia (Caster, 1939) in an earlier posting (CLICK HERE) but Dave at Views of the Mahantango blog pointed out that error.

Thanks to Kenny for cleaning the matrix off this specimen with sand abrasive cleaning.  See further down in this posting for before and after pictures of both sides.  It really is clean!

Aulopora Corals on Brachiopods

Included in this posting are pictures of Aulopora sp. coral fossils that colonized a brachiopod shell surfaces. It was attempted to clean the corals using sand abrasive air cleaning but that was with limited success.  The process took too long to remove matrix from the corals and at times would detach them from the shell.  This matrix of Silica Shale is some what harder than found on similar corals from southern Indiana.

As a comparison to the Silica Shale, the next two images are Aulopora sp. corals encrusted on a Spinocyrtia euruteines brachiopod from the Silver Creek Member, North Vernon Limestone of Clark County, Indiana USA.  This limestone matrix is softer and these Devonian fossils are composed of a reddish-purple colored material.

Here are some corals growing on a Spirifer brachiopod.

If you click on the last to pictures to see the full image size and then magnify portions of the fossil, one can see some micro coral colonies that formed on both sides of the shell.

Thanks to Kenny for doing some prep work on these fossils.  The Silica Shale fossils belong to Dave at the Views of the Mahantango blog.  Learn more at his blog post: CLICK HERE TO VIEW

Megastrophia (Silver Creek Limestone)

This brachiopod fossil is a nice find in that is over 5 cm in width.  It appears to be intact though needs to be cleaned with sand abrasive cleaning. Usually only the top half is found of this genus, Megastrophia.  These types of brachiopods might be one of the largest found in the Devonian layers around southern Indiana.

Fossil was found in the Silver Creek Member of the North Vernon Limestone of Clark County, Indiana, USA. This layer dates to the Devonian Period (Eifelian).

Hopefully, a posting of it cleaned up can be presented...

Aulopora on Orthospirifer Brachiopod

One of the easier fossils to prep with sand abrasion cleaning are specimens from the Silver Creek Member, North Vernon Limestone of Clark County, Indiana USA.  I believe it is this layer of limestone that the county's large concrete plant uses to manufacture product.  This fossil is the Orthospirifer brachiopod and it has a nice colony of Aulopora coral growing on it.  The brachiopod and coral lived in the Middle Devonian Period.

Thanks to Kenny for cleaning this one up for me!

Horn Coral Image Processed with Helicon

Image of a horn coral that might be either a Hetrophrentis or Siphonophrentis of the Beechwood Member, North Vernon Limestone, Givetian Stage.  The new twist on these image is that they are composites of 2-5 images created by Helicon Focus 5.1. After using the software with just the default it was very quick to start producing processed images.  Right now I am using the 30 day evaluation version.  This program would be really nice to process microscope images.

The image below illustrates the difference between a DSLR camera with 50 mm macro lens image and the Helicon stacked image on the right.  One can see that the depth of field of the lens only lets the middle section of the horn coral to be in focus leaving the top and bottom views blurred.  If a series of images are taken which gradually brings sections of the object into focus, the stacking software can combine the focused sections to create a composite image. This effect can really be seen on microscope images where the specimen has lots of depth.  I do not have a fixed camera mount for the microscope so composite imaging cannot be demonstrated.

The image stacking software was produced by the Ukrainian company Helicon Soft Ltd.  From what I have seen so far, a very nice piece of software.  There is a stacking feature in Photoshop but I did not produce the results like those shown here.  Maybe I am using it incorrectly though.

Horn coral fossil is from the Middle Devonian Period and was found in Clark County, Indiana, USA.

Phacops Trilobite with Tentaculites

This plate was recently sand abrasive cleaned.  It revealed the cephalon of a Phacops rana (Green, 1832) trilobite with a Tentaculites (Schlotheim, 1820) in front of it.  The Tentaculites (Schlotheim, 1820) was in between a broken segment of Phacops (Emmrich, 1839) thorax.  Further exploration of the plate reveal pieces of unidentified bryozoan and Protoleptostrophia (Caster, 1939) brachiopod.

Matrix is Silver Creek Member of North Vernon Shale Limestone of Clark County, Indiana.  Fossils are from the Middle Devonian Period (Eifelian) dating approximately 397 to 391 million years ago.

Unfortunately, I did not take a picture of the plate before I cleaned it.  Curses!

Protoleptostrophia perplana Brachiopod

Half of an internal Protoleptostrophia perplana (Conrad, 1839) brachiopod found in the Silver Creek Member of the North Vernon Limestone.  Specimen found in Clark County, Indiana.  Brachiopod existed in the Middle Devonian Period (Eifelian).

While this fossil is not complete, features I like are the muscle scars and exposed hinge teeth. It might be mixed in with other brachiopod fragments of Chonetes and Sprifier. 

The Silver Creek Member ranges 0-9 meters in thickness through out Clark County.  Described by (Campbell & Wickwire, 1955) as "homogeneous, fine-grained, bluish to drab or gray, argillaceous, magnesian limestone". I find it to be a light gray to whitish in color and quarried for cement.  Maybe it is the reason Cementville exists with the Essroc plant in Clark County.  It was named by C.E. Siebenthal in the 1901 Indiana Department of Geology and Natural Resources Annual Report 25. 

Sources for identification:

Formations of Ordovician, Silurian, and Devonian Rocks in the vicinity of Hanover, Indiana Compiled by Guy Campbell and Grant T. Wickwire - January 1955.

Picture on fossilpictures.wordpress.com web site.  Especially picture located lower left corner (click to enlarge).

Heliophyllum of the North Vernon Limestone

Heliophyllum sp. horn coral found in the Beechwood Member of the North Vernon Limestone of Clark County, Indiana.  This coral existed in the Devonian Period.

Bordenia knappi

A horn coral named after William Borden whom Borden, Indiana was also named.  Mr. Borden made a fortune mining silver in Colorado in the late 1800s and returned to Indiana.  His geology collection became very large and after his death transferred to the Field Museum in Chicago.  He might be best known for creating the Borden Institute and Museum to help educate youth in the southern Indiana area.

This horn coral is actually two clustered together but 90 degrees out of phase.  It is called Bordenia knappi (Hall, 1882) and found in the Speed Member of North Vernon Limestone.  It was found in Clark County, Indiana, USA and the coral existed in the Middle Devonian Period (Eifelian).

The species was named by Dr. James Hall in the 35th Annual Report of the State of New York, page 438 in 1884. It was named in honor of Professor Hall's friend long time fossil hunter Dr. James Knapp of Louisville, Kentucky, USA.

The genus Bordenia was named by long time fossil collector from New Albany, Indiana, USA George K. Greene in 1903 in Contributions to Indiana Palaeontology Volume I, page 99, plates 31 figures 4-11. He named it for William Borden who he later sold his collection to.

A Devonian Cephalopod

One of the more interesting things to do is to pick up rock plates with lots of fossils on them when on collecting expeditions. They can then be studied later after a cleaning where a world of surprises can be revealed.


This rock plate was found in Clark County, Indiana and is probably Silver Creek Member of the North Vernon Limestone. The fossils seen on it are from the Devonian period (Eifelian). It has purple colored brachiopods (Athyris fultonensis (Swallow, 1860), Mediospirifer, or Devonchonetes (Muir-Wood, 1962)). I used the KYANA Geological website Devonian brachiopod section to come up with those names. I also found a few Phacops rana trilobite molts, crinoid stems and spines.


The focus of my attention is the funnel shaped fossil that is about 5 cm long and 5 mm wide at one end and 2 mm wide at the other. After my May 4, 2009 post about Dry Dredgers members identifying the Ordovician rock's funnel shaped fossil as a cephalopod I took a new look at this one. Even using a magnifying lens I cannot see signs of a texture. I was looking for rings that might show it is a deformed crinoid stem. I saw some evidence of manganese oxide dendrites at one end.

In addition, it would be interesting to know what the spines on this rock belonged to. I assume they came from a crinoid calyx but maybe it was spiny snail.

Dolatocrinus vetusus Crinoid

This picture was taken of a fossil in the winning display case at the GeoFair 2009 in Cincinnati, Ohio.

This crinoid calyx fossil is called Dolatocrinus vetusus from the Middle Devonian Period. It was found in the Beechwood Member, North Vernon Limestone from Clark County, Indiana USA.