Arachnophyllum pentagonum Coral Fossil

 

The colonial rugose coral fossil pictured above is known as Arachnophyllum pentagonum (Goldfuss, 1826). It was found in the Louisville Limestone of Jefferson County, Kentucky USA. The fossils date to the Silurian Period. This coral fossil was once part of the collection of southern Indiana paleontologist George K. Greene (1835-1917). It appeared that all of Greene's fossil collection was sold to American Museum of Natural History in New York City after his death but as it turns out there was one cabinet not sold and was past down to his descendants. 

This fossil is now on display at the Falls of the Ohio State Park Interpretive Center till September 2024 after that it will be transferred to the Indiana State Museum. George Greene's great-great-grandson William "Bill" Bishop passed away on November 29, 2023 and his wish that fossils be donated.

Thecia minor Coral Fossils

Here are some pictures of a coral fossil known as Thecia minor (Rominger). They are found in the Louisville Limestone of Jefferson County, Kentucky USA. The fossils date to the Silurian Period. They were once part of the collection of southern Indiana paleontologist George K. Greene (1835-1917). It appeared that all of Greene's fossil collection was sold to American Museum of Natural History in New York City after his death but as it turns out there was one cabinet that was not sold and was past down to his descendants. 

These fossils are now on display at the Falls of the Ohio State Park Interpretive Center till September 2024 after that it will be transferred to the Indiana State Museum. George Greene's great-great-grandson William "Bill" Bishop passed away on November 29, 2023 and his wish that fossils be donated.

Myelodactylus Crinoid Fossil Revisited

Years ago I posted a picture of a fossil crinoid Myelodactylus convolutus (Hall, 1852) that is normally seen coiled up. This fossil specimen was elongated as when it died it was attached inside a colonial Entelophyllum eruciforme (Davis) coral. After reading up on this type of crinoid, this is a very rare occurrence of the crinoid preserved in this position to find in the fossil record (normally fossilized curled up).

This next picture shows the fossil with a scale. It is about 5 cm long. Note the remaining holdfast at the bottom of the crinoid fossil that anchored it to the coral. Each of those little holes would have contained a cirri.Unfortunately, the calyx or crown is missing from the top of this specimen. 

My cousin Kenny has been working on cleaning this coral fossil and it seemed like a good time to post some updated images. Also a few new surprise fossil finds in the coral including maybe another Myelodactylus in the coral. Look at the reverse S shape in the picture below with cirri or some type of holdfast on top of an Entelophyllum coral fossil.

Next to that fossil are the remains of an eroded crinoid which I cannot identify.

A year before his death, renowned crinoid researcher Frank Springer (1848-1927) of the United States National Museum published "Unusual Forms of Fossil Crinoids" in 1926 (LINK). This 137 page treatise mentions the Myelodactylus quite a bit with a number of images in the plates. It is found in the Silurian Period Rochester and Waldron Shales.

In my opinion, this coral specimen should eventually be in the Smithsonian Museum of Natural History to be part of the Springer Collection of echinoderm fossils. Learn more at their web page as of this writing in March 2024. I believe there could be more Myelodactylus crinoids hidden in the coral that future scanning technologies will be able to non-destructively detect. The Smithsonian would have the resources to do instigate this research.

Halysites louisvillensis Chain Coral Fossil

 

This specimen is somewhat unique in what is normally found, it contains very visible mesocorallites quadrilaterals. It is described as a new species in Erwin Stumm's Silurian and Devonian Corals of the Falls of the Ohio on page 79 as Halysites louisvillensis (Stumm, 1964). Stumm writes about it, "The species is externally similar to Catenipora microparus (Whitfield) but differs in the presence of the very small mesocorallites."

Most of the specimens of chain corals I have seen, one cannot see the little square shapes in between the chain shapes. It is possible they are there but after hundreds of millions of years they blended together obscuring the four sided shape.

This fossil is found in the Louisville Limestone of Jefferson County Kentucky USA. It dates to the Middle Silurian Period.

 

Favosites niagarensis Coral Fossil

My cousin Kenny sent me some images of something he had been working on recently. He extracted a silica coral fossil from a boulder using muratic acid. What emerged was a Favosites niagarensis coral with other corals or stromatoporoids. The fossil was found the Silurian Period Louisville Limestone of Jefferson County Kentucky USA.

Arachnophyllum striatum Coral Fossil

Images of what appears to be an Arachnophyllum striatum coral fossil. It was found in the Louisville Limestone of Jefferson County, Kentucky USA. The fossil dates to the Middle Silurian Period. Thanks to Kenny for help with identification on this fossil.

Myelodactylus convolutus Crinoid from Louisville Limestone

Recently, I have tried to put more effort in labeling a lot of collected fossils in my collection with names. At times difficult, due to poor note keeping by me when I picked them up or received them from someone else. So I sometimes rely on the previous posts to help figure out what was found and when. While looking back, I found that I had a number of unidentified fossil entries that I did not visit again to give a name. One was from May 10, 2010 which turns out to be a Myelodactylus convolutus? crinoid.

My cousin Kenny helped with the full name and sent me a picture of one from his collection seen above. This one is younger in that it was found in the Louisville Limestone and not the Waldron Shale. The fossil was found in the Jefferson County Kentucky USA and dates to the Middle Silurian Period. Also look at the blog post in 2014 showing one fully extended and attached with holdfast to a large coral.

This crinoid was unique in that the remains shown are believed to be its stem and not just an arm. In that inner coil would be a calyx with arms. Unless it was quite small on this species I do not see where the calyx is thus must have snapped off.

Refer to this article Myelodactylid crinoids from the Silurian of the British Isles by Stephen K Donovan and George D Sevastopulo from 1989 Palaeontology Volume 32 pages 689-710 at https://www.biodiversitylibrary.org/part/173971#/summary Plate 81 shows clear examples of what the calyx looked like though it might be somewhat different in the species of this fossil

Polyaxons strongylasters Sponge Spicule Fossils

These images are of Polyaxons strongylasters sponge spicule fossils. They were found trapped in cavities in Halysites coral fossils and a microscope is needed to see them. The images have a 1-2mm field of view.

The fossils were found in the Louisville Limestone of Jefferson County, Kentucky USA. This layer dates to the Silurian Period.

Thanks to Kenny for images and discovering them with his microscope.

Myelodactylus Crinoid Attached to Entelophyllum Coral Fossil

This picture shows very small crinoid fossil attached to a larger colonial coral fossil. It was found in the Louisville Limestone of Jefferson County, Kentucky USA.  The crinoid fossil appears to be a Myelodactylus. The colonial coral might be an Entelophyllum rugosum?. They existed in the Silurian Period.

Visit the Falls of the Ohio State Park web site for some example pictures of the Myelodactylus crinoid (scroll down toward the bottom of the page).

Consult Erwin Stumm's 1964 book Silurian and Devonian Corals of the Falls of the Ohio page 32 and plate 22, figures 9-13 (pages 112-113) for more information about the coral fossil.

Thanks to Kenny for the picture of this nice fossil.

Aulopora pygmaea Coral Fossil

Here is a picture of a very small fossil found in the Louisville Limestone of Jefferson County, Kentucky USA.  The fossil appears to be an Aulopora pygmaea. It existed in the Silurian Period. I am use to seeing Aulopora growing on brachiopod fossils but this one appears to be a stand alone colony.

Consult Erwin Stumm's 1964 book Silurian and Devonian Corals of the Falls of the Ohio page 84 and plate 77, figure 7 (pages 168-169).

Thanks to Kenny for the picture of this nice fossil.

Surface Detail of Arachnophyllum mammillaire Coral Fossil

These images are of the surface details of an Arachnophyllum mammillaire (Owen) colonial coral fossil. It was found in the Louisville Limestone of Jefferson County, Kentucky. The fossil dates to the Middle Silurian Period.

Thanks to Kenny for these pictures.

Arachnophyllum Colonial Coral Fossil

These images are of an Arachnophyllum mammillaire (Owen) colonial coral fossil. It was found in the Louisville Limestone of Jefferson County, Kentucky. The fossil dates to the Middle Silurian Period.

Thanks to Kenny for letting me take pictures of it.

Silurian Green Fossil - Bickmorites?

Sometimes when one is searching for fossils in the field, color is important as opposed to just trying to visually match shapes and patterns. In the case of today's posting, the color green is important. The Silurian Period Louisville Limestone found in Jefferson County, Kentucky at times has green blotches that show through. I assume this is a sign of some sort of copper being present. (UPDATE: see comment section as the green material might be glauconite.) My cousin told me this could be a sign of a cephalopod fossil which tend to be difficult to find in this rock layer. Mostly one finds corals (chain or colonial types) and some brachiopods with rare trilobite or graptolite fragments. Years ago, I saw cephalopod fossils found by others but recently I came across the remains shown in these first three pictures. After visiting the Indiana State Museum and seeing some of their Silurian cephalopod specimens, a green color was present in some of those specimens. Their material was from the Wabash Formation if I remember correctly. This formation might not quite match up with the Louisville Limestone.

These next two Bickmorites sp. specimens can be found on the first floor of the Indiana State Museum as of May 2012. They are in the fossil area in the Silurian case.

See a Bickmorites sp. specimen at the Indiana State Museum on-line database.

Last two images are magnified areas of the green fossil I found in the Louisville Limestone. Learn more about these creatures at this web site.

UPDATE:
A reader of this blog, avid fossil collector, and chemist Jack Kesling of Pennsylvania sent me a nice fossil find that relates to this posting. He found this unidentified Silurian cephalopod fossil with a lot of greenish material on it. The fossil was found in the Bertie Formation of Herkimer County, New York.

Photo by Jack Kesling

Chain Coral

This fossil might be a Halysites louisvillensis? found in the Louisville Limestone of Jefferson County, Kentucky. Corals grew on the seafloor in the Middle Silurian Period. Fossil needs to be sectioned to get an accurate identification.

Entelophyllum Museum Grade Coral

This series of pictures shows an Entelophyllum (Wedekind, 1927) coral found in the Louisville Limestone of Jefferson County, Kentucky. Using large amounts of muriatic acid and patience, this coral was revealed from its limestone matrix. It is almost 20 cm long. These first two pictures show evidence of the corallites budding from a parent.

The two images after that show the talons that connected the corallites together. Three species of Entelophyllum are found in the Louisville area: E. eruciforme (Davis), E. rugosum, and E. strictum. This coral is from the Middle Silurian but can sometimes be confused with the Devonian Eridophyllum found in the Jeffersonville Limestone. The genus has also been known in the past by the name Diphyphyllum or Xylodes.

Thanks to Kenny for letting me photograph this specimen and good job on its preparation.

Close ups of the corallites side view.

Close up of some of the coral septas in the colonial mass.