Small sponge from the Widder formation

On a trip to the exposures of the Widder formation along the Credit river in Hungry Hollow, Ontario, I found this cluster of sponge spicules. It is not uncommon to find individual spicules like this within the Hungry Hollow member of the Widder formation, but a large cluster like this is less common. I checked the "Check List of Fossil Invertebrates Described from the Middle Devonian Rocks of the Thedford-Arkona Region of Southwestern Ontario" by Stumm and Wright (1958) and they list one sponge known from the Widder formation: Astraeospongia hamiltonensis.  I am familiar with that genus from the upper Silurian where it is known as Astraeospongia meniscus from the Brownsport formation. The spicules in my specimen look very similar to those earlier species so I think I will stick with the name Astraeospongia hamiltonensis.

I collected this specimen from the Hungry Hollow member of the Widder formation which is Devonian in age, Givetian stage.

Hindia sp. sponge from the Coburg fm.

When you see a small rounded pebble looking thing on the ground, you often think it is just a water worn pebble. However, when you find it in a limestone quarry among freshly blasted rock, it might just be a small sponge called Hindia sp.  I've found one example of this at the St. Mary's Cement Quarry and I believe it is from the Coburg formation (as that is 90% of the exposed and quarried rock). However, William Hessin's book, "South Central Ontario Fossils", only mentions it being present in the Verulam formation.  It could either be that Hinda sp. is rare in the Coburn,  I picked this up from a part of the Verulam formation, or it got transported during a blast.  In any case, I don't have any that I know of from the Verulam either so this is still a win for me.

Hessin reports that there are two species of Hinda known from the Verulam formation but that they differ in the size and arrangement of the surface pores. I have not yet had a chance to view this specimen under a microscope so I am sticking with Hinda sp. for now.

I have found this genera also in the Lower Devonian of Oklahoma and the Lower Devonian of New York.


The Coburg formation is Ordovician in age (late Ordovician, Katian/Mohawkian stage).
This fossil was collected from the St. Mary's Limestone Quarry in Bowmanville, Ontario. I used William Hessin's book "South Central Ontario Fossils", 2009, Self Published, pg. 58 to help identify this fossil.

Hindia sphaeroidalis sponge from the Viola formation of Oklahoma

I found one specimen of the sponge fossil called Hindia sphaeroidalis. in the Viola formation roadcut south of Sulphur, OK. This species spans many millions of years and is known in rocks from the Ordovician up through the lower Devonian. I've also found examples of this species from the lower Devonian aged Kalkberg formation of New York, but there they seemed to get much larger. The shape of the fossil is like a large pea with many small openings on all surfaces. The round shape seems to infer that it preferred an environment near the wave base where it would be rolled around at times. This is the first specimen I have found from the Ordovician.

A closer view showing the many tiny openings on the surface of the fossil.

This specimen comes from the Viola formation which is upper Ordovician (Sandbian to Katian stage) in age and overlies (unconformably?) the Bromide formation. I found it in a road cut along US 177, south of Sulphur, Oklahoma.

Hindia sphaeroidalis sponge from the Kalkberg formation of New York

Sponges are not something I typically look for while collecting but some of the specimens of Hindia sphaeroidalis that I found in the Kalkberg formation of New York were nearly the size of a ping pong ball! I know that Hindia is a somewhat common sponge from the Ordovician up through the Devonian but these are the first specimens I have found. H. sphaeroidalis forms a round sphere or ball shape with no one particular surface being an obvious "top" or "bottom". I suspect this is because it rolled with the waves or currents on the sea floor rather than secure itself to a single spot. Other than the round shape, the only other way you can recognize this fossil is the granular surface which is in contrast to the typically fine, smooth limestones of the Kalkberg.

Specimen #1

Specimen #2 - with some matrix still attached.

Specimen #3 - This is an odd one in that it is somewhat flattened but it does not appear to be the result of compression.

Here are the three above specimens in a side by side shot to show the variation in size.

Specimen #4 - This is the only specimen I found with any sort of mark or area that broke the round surface. The dimple shape on this specimen is unusual and might be the result of the specimen growing next to another of it's species. I do not think it is a different species or genera as there are no other indicative markings to be found and the rest of the specimen conforms to the generally spherical shape know for H. sphaeroidalis.

The Kalkberg formation is lower Devonian in age (Lockhovian to Pragian stage). I collected this specimen from a roadcut near Shoharie, NY.

Clionolithes sp. borings (?) in M. arkonensis shells from Arkona

A trip to Arkona last fall yielded a fine specimen of Mucrospirifer arkonensis that is perhaps the most complete specimen I've found to date. I found it while attempting to traverse the always slippery Arkona formation (Devonian, Givetian stage) and noticed it sticking out of the hillside. It also shows signs of another kind of trace fossil that I've not seen before. Here is the shell fossil showing that it is about 90% complete missing only the very tips of the wings that project along the hinge line. But notice also the little pepper like flecks that are scattered across the surface.

A closer view of those flecks show that they are, in fact, trace fossils from some kind of burrowing organism. Interestingly, they appear to be concentrated in the brachial valve and seemingly spread from the hinge line towards other parts of the shell.

A closer view

In doing a little research they look similar to borings that a sponge would make and there is a known genus,  Clionolithes, that has been erected to account for these. Most of what I can find on Clionolithes is based on fossils from the upper Devonian and speaks of radiating or branching features. The specimen I have does not appear to show clear lines that radiate from a central point but they do show some evidence of branching occasionally. As I study them they almost appear like stitches in cloth whereby the burrow seems to rise and fall through the shell. Perhaps these are actually worm borings rather than sponge but I can't find any good info to indicate other wise.


I found a second specimen on that same trip that shows similar markings along with some Aulopora elleri on the surface.

Hopefully I will find more specimens with this feature on them during future trips to Arkona. I'd like to see if they are isolated to M. arkonensis or if they also appear on other species.

The only other evidence of boring sponges that I personally have found are of Cliona cretacica on oyster shells from the Cretaceous sediments of Delaware and New Jersey.

Hydnoceras bathense fossil glass sponge from New York

Below are some pieces of a glass sponge called Hyndoceras bathense from the upper Devonian (Fransian stage) of New York. It comes from rocks that are part of the Chemung Group but I don't have more specific formation or layer info. Sponges are somewhat rare the find fossilized as they are composed of many tiny spicules that are held together by the fleshy parts of the body. When they die the fleshy parts decay and all the spicules get scattered. For the specimens below to have been preserved they must have been rapidly buried during a storm event or an underwater landslide.

The first two specimens are just one side of the sponge. Either the fossil split or was not preserved on the other side.

Specimen #1

Specimen #2

Specimen #3 is fully complete and 3-dimentional (except for being compressed by the sediments)

Specimen #4

I purchased these specimens at my local Delaware Valley Fossil Society club show in April.

There is an impressive piece from West Virginia with multiple specimens that can be seen on the West Virginia Geological and Economic Survey page.

Evidence of the boring sponge Cliona cretacica from the Cretaceous of Delaware

Below is a specimen which is interesting due to the evidence of epibonts. It's a piece from an large oyster shell that was found in Delaware along the C&D canal spoil piles (Cretaceous aged sediments dredged from the canal in the 1970's). Upon and within the shell is evidence of multiple generations of the boring sponge Cliona cretacica along with some bryozoan colonies. There is even evidence that the bryozoan colony skeletons themselves may have been later victims of the sponge.

A view of the whole specimen shows the holes in the shell that are from the boring sponge and the bryozoan colonies.

Close up of the bryozoan fossils....

... and the traces left by the sponge.

Cliona didn't parasitize or kill the Oyster who originally made the shell nor the bryozoans. It merely scraped out a home for itself within the calcareous remains and possibly utilized the calcium for it's own skeleton. Because the sponges bodies quickly fell apart after death we don't have many direct fossils of them. Instead we are left to interpret the evidence they left behind of how they impacted their environment. This is also good evidence that some oyster shells laid on the surface of the seafloor for long enough to provide a habitat for other animals.

Cnemidiastrum stellatum from Poland

Following up on my previous post, here is another sponge that I think is Cnemidiastrum stellatum. It is from near Zalas, Poland and is also from the Jurassic (Oxfordian stage) like the previous specimen.

These are views of the sides of this conical shaped specimen.

I'm guessing the large hole on the side is the result of another creature living within the structure of the sponge?

Top surface

Detail of the upper portion