Ordovician Tentaculities Fossil

Tentaculites (von Schlotheim, 1820) fossil that is of an uncertain affinity. Image taken under microscope and field of view is 3 mm. Found near Brookville Lake, Indiana and Waynesville Formation dates to the Ordovician Period.

Thanks to Kenny for the image. 

Tentaculites richmonensis Fossils

Here is an image of a nice plate of fossils found in the Lexington Limestone of Franklin County, Kentucky USA. There are at least 8 Tentaculites richmonensis shown in the image around that brown object which is an Isotelus trilobites hypostome (feeding scoop). Also in the images are brachiopods and bryozoans. Fossils date to the Ordovician Period.
Thanks to Kenny for image.

Tentaculites with Devonochonetes

Presented for your visual inspection, a Devonian hash plate from the Silver Creek Limestone of Clark County Indiana.  An intact Tentaculites with a lot of Devonochonetes brachiopods.

The Tentaculites is an extinct molluscs that lived in the Devonian and Silurian.  The ringed cone like shell is known as a conch.  Study of Devonian pyrite specimens from Germany alludes to the creature having tentacles.   So maybe they were like miniature shelled squids.  The next image shows the Tentaculites being about 1 cm in length.

Learn more about Tentaculitoids in the 1996 book Fossils of Ohio, Chapter 20 (pp.282-287) written by Stig M. Bergström.

This fossil is available for purchase on eBay CLICK LINK HERE.

On one side of this limestone block, is a cross section of a brachiopod with calcite crystals.

On the bottom of the plate are more remains of brachiopods plus this pygidium of a trilobite.  More that like it belonged to a Phacops.

View of top of plate:

View of bottom of plate:

View of one of the sides:

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!

Rafinesquina Encrusters

These Rafinesquina brachiopods from the Ordovician Period found in Kentucky have some encrusting creatures on them.

This first specimen I find the most interesting. It has a type of matting bryozoan and either a branching bryozoan like cyclostome or coral like Protarea richmondensis. See these nice pictures on the Kentucky Paleontological Society website: encrusting Protarea richmondensis coral on Rafinesquina and Cyclostome bryozoan and Cornulites worm tubes encrusting Rafinesquina
 

This next Rafinesquina brachiopod has imprints of the tubes of either a Cornulites worm or Tentaculites.

 

An inarticulate brachiopod has made its home on shell edge of this Rafinesquina brachiopod.

  

A number of bryozoan colonies can be seen on shell edge and shell body of this brachiopod.

  

Not really any visible encrustations on this brachiopod though an interesting indentation.

 

Thanks to Herb for the images of some of his brachiopod specimens.

Future Work Needed on Kope Formation Fossils

The following pictures show rocks that will need future preparation work to reveal more of the remains of the ancient sea creatures they contain. The fossils were found in the Kope Formation, Carroll County, Kentucky. They are from the Ordovician Period.

This first rock shows a Cryptolithus trilobite fragment with an exposed spine. I have overlaid the trilobite image to show what it might have looked like intact.

Another Cryptolithus trilobite fragment that after some work might show more of the cephalon portion.

It might be hard to expose the rest of this Cryptolithus trilobite fragment because is appears to be surround by other hard fossil fragments.  It sort of reminds me of a horseshoe.

This piece has potential but has quite a bit of hard fossil debris in between to the two cephalon sides. 

The arrow marks an unidentified fossil that needs more cleaning to reveal details and surface area.

 

This fossil could be a Tentaculites or maybe some sort of worm tube.  Hopefully more of it will be embedded in the matrix.

 

Devonian Tentaculites scalariformis?

This is a Tentaculites scalariformis (not sure about species) that lived in the Devonian period. It was found in Jeffersonville Limestone in Clark County, Indiana. I have been looking for another one of these for a while. This one is still in the rock with a lot of small brachiopods. The tip is quite small and fragile so it would be unwise to remove it from the rock.

Under magnification the tip still has its growth rings. The pictures show two side of the rock with one revealing much more of the creature's shell. The last picture has a different color because I was using a different light.

Tentaculites scalariformis

Phylum Mollusca and the class is Gastropoda making this creature a small snail.

Its distinctive shell makes it look sort of like a very small cephalopod.

I think this creature is Tentaculites scalariformis.

In the "North American Index Fossils Invertebrates Volume II" by Amadeus W. Grabau and Hervey Woodburn Shimer from 1910 on page 10 describes Tentaculites as:
"Shell straight or slightly curved, elongate, tapering, conical, with circular cross section and terminating posteriorly either acutely or in a bulb. Surface marked by strong tranverse rings which are closely arranged near the apex and more distant and stronger near the mouth. Fine transverse and rarely longitudinal striae are present. Apical portion often filled with calcareous matter or divided off by transverse septa."

It goes on to say creature existed in the Ordovician to Devonian periods with it being very abundant in the Silurian and Devonian periods.

The book describes T. scalariformis (Hall) as:
"Differs from T.bellulus in the more obtuse annulations of the distal portion, with narrower interspaces, and in the more rapidly narrowing apical portion. Onondaga of New York, Ohio and Indiana."

It is also described in the Indiana Department of Geology and Natural Resources Twenty-Fifth Annual Report issued in 1900 on page 736.