Hunting the Roadcuts of Indiana's Ordovician

[Wrangellian]

Good report.. I'm starting to feel like I've been to some of these sites due to members' 'tour guides' - When I scrolled down thru your pics before reading, I thought "That looks like St Leon"... and I was right.

[digit]

Virtual fossil hunting at its best. I've seen photos of some places before I've got there in person and it is kind of interesting standing in a place that you've seen only in images before. I had a really weird surreal feeling standing in front of a couple of famous moai on Easter Island a few years back and having to almost pinch myself to verify I was actually there on the spot. These were a little over the 50 pound limit for my suitcases so I decided to leave them behind--but I know right where I left them so I can always go back and get them later.

Cheers.

-Ken

[Mediospirifer]

Hi, Ken! It was a lot of fun meeting you in the field and sharing a trip. I just noticed today that your report was posted, so I thought I'd add a hello.

You did get some nice pieces. I'm glad you found a good Vinlandostrophia. They are cool! And the doubly-drilled Glyptorthis is also a good piece. If you have a bunch of those, look closely at the spaces between the main ribs; if the finer striations are absent, you might have a Cincinnetina meeki.

I'm not ready to add my specimens yet (cleaning fossils is on hold temporarily due to wrist pain ), but I'll get there... One of my Glyptorthis specimens is not only pathological, it has two bite marks!

Did you pick up any of the tiny brachiopods that were all over the St. Leon site? There are a few visible in your in situ photos. They're Zygostrophia modesta (if you were wondering).

[Jeffrey P]

Happy Birthday Ken and congratulations on a great report and excellent finds. Looks like you really took advantage of your time. St. Leon is definately a must on my bucket list of places to visit someday.

[Khyssa]

Happy belated birthday, Ken! Looks like you and Tammy had a fun trip. And as always your trip report has been fantastic to read. Looking forward to hopefully seeing the two of you in a week or so.

Kara

[dalmayshun]

Great report, thanks. I hunt Ordovician in the U. P. of Michigan near the Lake Superior campground I go to for a couple of weeks. In driving around, I happened upon a degrading hillside, filled with nodules...have been back each year since I discovered it and always find interesting things...I also hunt Ordovician near Green Bay close to my childhood home. I know the owners of a quarry who allow me to hunt on Sundays when they are closed...since both places change yearly, it is always exciting to find new things. Your report makes me excited to plan my next trip there in August. Thanks again...

Edited June 17, 2016 by dalmayshun

[digit]

I've finally had some time to organize some of my finds from this trip and setup the camera with the macro lens to get some images. So here are some photos of a variety of things from the St. Leon roadcut.

First, a look at my small hoard of crinoid stem pieces--I'm assuming Cincinnaticrinus pentagonus given the 5-sided markings visible in the cross section of these small pieces. Looks like a handful of springs or headless screws.

I had read up on this site and knew that Isotelus trilobite fragments are pretty common but that large sections would be rare finds. These all had the same brown coloration which made them easy to spot. A few fragments were identifiable enough to make out where on the trilobite they came from but most were too small to say anything more than they once were part of a very large trilobite.

I did get one complete trilobite though--a rolled Flexicalymene. Also found two flexi pygidium (trilo-butts) which are interesting in that they are still identifiable as being from a trilobite but not as cool as the garbanzo bean sized complete specimen.

I also knew that straight shelled nautiloid cephalopod casts might be found here and so I knew what these tiny fragments were when I spotted them.

[digit]

There were also lots of fragments of branching bryozoan colonies that were pretty common and easy to spot. One species has a very bumpy texture and I've heard described informally as the "chicken skin" bryozoan--with good reason.

I also found a few horn corals. Mostly I think these were Grewingkia but I may also have some of the smaller species with the wider opening and narrow bottom--Streptelasma. Some of these were found attached to the matrix and most were pretty beat up and crushed but I did get a few that were reasonably decent looking.

[digit]

A lot of the brachiopods we found were shingled together in thick compacted slabs. We did find many that were weathered out. It took some time to start finding examples with both shells together making a complete specimen. We found a lot of Rafinesquina but there is also a similar flattened genus called Strophomena and I don't know enough about brachiopods to tell the difference at this point. It is interesting that some of these brachiopods are as thin as a potato chip--well, maybe a thick "kettle style" chip, anyway--and some were thin but cupped forming strongly convex and concave sides. I believe the older larger specimens tended to be more cupped.

I found a number of small brachiopods that were only around 7mm across and I don't know if these are just juveniles of one of the larger species or some sort of a tiny species. There were quite a number of this small size class. EDIT: Could these possibly be the tiny brachiopod Zygospira?

The genus Lepidocyclus was pretty common at the site and several whole specimens were collected along with numerous halves. The middle one on the top row is definitely something else but I think many or all of the rest may be Lepidocyclus. I'm a rank novice at Ordovician fauna so I could be completely off base.

Edited June 19, 2016 by digit

[digit]

Possibly my favorite brachiopod of the day was the Vinlandostrophia cypha (top in photo below) that I found high up the steep slope at the second spot we stopped at. It's the one with the pointy ends and the really cool raised area at the midline that gives the shell a sort of W-shaped opening. The lower one resembles this but is likely different. I don't know how much variation there are within species and how many similar looking brachiopods may belong to differing genera so I'm guessing at most of this.

At the third site we stopped at we found a huge number of Glyptorthis insculpta. They were so common that you could just sit in one place and collect a small bag full of these (which I did).

Some of these tended to be flatter specimens that also seemed to have much more matrix left between the ridges on the shell (top row) and some seemed to be much thicker with more volume and for some reason they tended to look more shiny with a silica like shell (bottom). This may be novice brachiopod bias here but I wonder why the difference? Here are images of both sides of this selection.

[digit]

While collecting Glyptorthis at the third site with Mediospirifer (the TFF member not the brachiopod), she told me that she likes to look for pathological specimens or specimens that had holes "drilled" into them by some boring organism. The pierced ones are pretty easy to see.

I found other examples where the shell was wrinkled and folded together a bit. Unfortunately, this is not particularly apparent from a top-down photo. I'll have to prop these up on edge so the crease can be more easily seen.

I found one brachiopod with some smaller fossils attached to the shell. I'm wondering if these might be the Tentaculites that I learned about from Mediospirifer?

[digit]

I collected several nice hash plates--some small palm-size chunks that displayed some nice fossils on one or both sides. I also collected some larger slabs as well which tested the limits of the 50 pound maximum on my checked bags.

Here is a nice little piece from the third stop--a hash plate packed with Glyptorthis. Looking at this piece on edge you can see a continuous layering of these shells throughout the piece. Here is a detail of a larger chunk of Glyptorthis laden has plate.

From the first stop (the St. Leon roadcut) I did select a couple of nice hash plates there as well. I particularly like this beefy one which is composed of shingled layers of these brachiopods all the way through. As this piece (some 11 inches across) has nice displayable surfaces on both sides, I think I'm going to display this piece standing upright. My plan is to get a tile saw and rip a flat edge along the "bottom" of the piece so that the plat will rest solidly on this edge. I'll probably fashion some sort of display base for it and I think I'll drill two holes into the cut edge so the piece can rest upon two dowel rod segments attached to the base as an extra means of keeping it from falling over.

As you can see, my wife and I had a great amount of fun during our introductory hunt through the Ordovician in southeastern Indiana. We look forward to heading back to that part of the midwest to expand our fossil hunting with new and exciting opportunities.

Cheers.

-Ken

[ynot]

Wow, wonderful and prolific finds!!

Tony

[fossilized6s]

nice finds, Ken! i still haven't had the pleasure of hunting that road cut yet.

[Khyssa]

Great finds!

[digit]

nice finds, Ken! i still haven't had the pleasure of hunting that road cut yet.

The St. Leon roadcut is incredibly saturated with fossils--mostly brachiopods. I can see why fossil clubs and paleontology classes have made repeated visits to this site over the years. I can see how some of the rarer finds (like trilobites) might be more plentiful immediately following a good rain but no matter how intense the hunting pressure at this location, it is too big and too dense with fossils to ever conceivably get hunted out.

Despite Google Maps optimistic forecast of 4 hours, it was every bit of 5+ hours and closer to 6 with breaks along the way. You would easily be looking at 7+ hours from your location. That's the kind of distance that is really pushing it for a day trip. I'd suggest making a long weekend out of it (at least) and finding an inexpensive hotel in the area. It really wouldn't do to drive a long way to get to such a great site as this and then feel rushed while collecting with the prospect of a long drive ahead of you. There are apparently quite a number of other roadcuts in the surrounding area and the biggest problem that I could see would be the reduced MPG on your return trip with half of the Devonian packed away in your trunk.

With any luck Mediospirifer will soon augment this posting with some of her finds from the trip. She is significantly more versed in the taxonomy of the brachiopods (and other critters) that occur in these roadcuts. We learned a lot collecting with her and her husband (and possibly even retained a small fraction). I've always said that it is more fun to collect with other TFF members. The shared knowledge and camaraderie enhance the experience. That's why I always make the effort to go out in the field with TFF members (either on my own home turf or while traveling). Running into another TFF member unplanned and impromptu--that's just priceless.

Cheers.

-Ken

P.S.: Don't be surprised if you see some Devonian material appear on a TFF auction sometime soon.

[Mediospirifer]

Nice collection! Its always cool to see what someone else found...and I should finish cleaning, sorting, and photographing my finds soon. I will certainly be happy to show my haul of rocks!

I found a number of small brachiopods that were only around 7mm across and I don't know if these are just juveniles of one of the larger species or some sort of a tiny species. There were quite a number of this small size class. EDIT: Could these possibly be the tiny brachiopod Zygospira?

2016-06-19 15-14-46.jpg

The genus Lepidocyclus was pretty common at the site and several whole specimens were collected along with numerous halves. The middle one on the top row is definitely something else but I think many or all of the rest may be Lepidocyclus. I'm a rank novice at Ordovician fauna so I could be completely off base.

2016-06-19 17-07-23.jpg

Yes, those are Zygospira. The largest I've seen is about 1 cm. I've also washed submillimeter specimens out of mud matrix from that site! I don't offhand know what your mystery brachiopod among the Lepidocyclus is, but if you post photos of it from a few different angles I may be able to ID it from my book. Or, you could look for it in this website: LINK. That's more up-to-date than my book is, if nothing else...

Possibly my favorite brachiopod of the day was the Vinlandostrophia cypha (top in photo below) that I found high up the steep slope at the second spot we stopped at. It's the one with the pointy ends and the really cool raised area at the midline that gives the shell a sort of W-shaped opening. The lower one resembles this but is likely different. I don't know how much variation there are within species and how many similar looking brachiopods may belong to differing genera so I'm guessing at most of this.

2016-06-19 15-11-15.jpg

At the third site we stopped at we found a huge number of Glyptorthis insculpta. They were so common that you could just sit in one place and collect a small bag full of these (which I did).

2016-06-19 13-26-33.jpg

Some of these tended to be flatter specimens that also seemed to have much more matrix left between the ridges on the shell (top row) and some seemed to be much thicker with more volume and for some reason they tended to look more shiny with a silica like shell (bottom). This may be novice brachiopod bias here but I wonder why the difference? Here are images of both sides of this selection.

2016-06-19 13-32-18.jpg 2016-06-19 13-36-02.jpg

I like the Vinlandostrophia, too. I think both of yours are, as there is some variation in the species. Here's a link to the page for Vinlandostrophia (formerly Platystrophia): LINK. Notice that one of the specimens they show lacks points, in my experience there are more that lack points than there are that have them.

You got a good bunch of Glyptorthis! I don't know why there are differences in the amount of matrix, or why that would correlate to how inflated the specimen is. I can speculate: 1) They may have weathered out of different layers, with subtly different fossilization conditions and properties of the matrix; 2) The correlation may be purely coincidental, and the matrix adhesion differences may be a weathering phenomenon; or 3) You may have some Cincinnetina meeki or Dalmanella emacerata in your bunch. Check the growth lines; if they're prominent, the specimen is Glyptorthis, if they're hard to see, it's one of the others. The site I linked above has fairly detailed descriptions of both, less on the Glyptorthis.

While collecting Glyptorthis at the third site with Mediospirifer (the TFF member not the brachiopod), she told me that she likes to look for pathological specimens or specimens that had holes "drilled" into them by some boring organism. The pierced ones are pretty easy to see.

2016-06-19 13-40-55.jpg

I found other examples where the shell was wrinkled and folded together a bit. Unfortunately, this is not particularly apparent from a top-down photo. I'll have to prop these up on edge so the crease can be more easily seen.

2016-06-19 14-23-21.jpg

I found one brachiopod with some smaller fossils attached to the shell. I'm wondering if these might be the Tentaculites that I learned about from Mediospirifer?

2016-06-19 14-33-33.jpg

The bottom specimen of your "wrinkled" brachiopods is pathological. Look at the indentation left of center on the bottom margin, and follow the plications. Normally, they diverge smoothly (as you have many examples of!). Yours had a bite taken out of it, and healed!

The other wrinkles (where the whole specimen is folded) are most likely geological artifacts. If the rock is distorted (slowly) after fossilization is complete, the fossils will distort along with it. So that's a record of geological processes rather than biological ones.

Your encrusting fossils don't quite look like Tentaculites to me--Tentaculites are more strongly ribbed, and usually are found free. You may have an encrusting tube-worm or something similar. It reminds me of the Devonian Cornulites, but I don't know what the Ordovician types would be. I'll take a look when I get home and see if my book has anything similar.

Cool stuff! I like the hash plates, too. I'd have a really hard time with a 50 pound weight limit for travelling. The first time my husband and I visited these roadcuts, we brought home 31 bags (8-lb canvas rice bags; each holds up to 20+ lbs of rock) of hash plates, mud matrix, and small finds!

I'll finish up with my finds and add some to the thread soon. I need to put it under magnification to be certain, but I think I have a pathological Vinlandostrophia!

[digit]

Thanks for all the information. When I get some more free time I'll setup the camera and try to get some more photos of my wrinkled brachiopods and maybe investigate my Glyptorthis closer too. Devonian brachiopods (and associated fauna) are a welcome diversion from shark teeth and Mazon Creek nodules which I've been immersed in recently. There is a whole world of different fossils out there and it is fun (and informative) to sample widely from the smorgasbord whenever possible.

Thanks again for the wealth of knowledge you bring to the forum. Looking forward to seeing images of what you went home with.

Cheers.

-Ken

[Mediospirifer]

You're welcome! A large part of the fun of collecting is sharing cool stuff and interesting information. I don't claim expertise in anything, but there are some areas that I have looked into researching. Mostly, I know a bit about my own finds, particularly those I consider tradebait. If I send someone a specimen or hash plate, I want to include as complete an identification as possible!

Enjoy the Mazon nodules! I have a box of them I need to process, but not enough room in the freezer to handle more then a small (pint-size) pot at a time. I would happily use the New York winter freeze-thaw cycle, but last winter had very little significant freeze. I hope you find something good in your nodules!

I agree wholeheartedly about sampling different types of fossil collecting. I'd really love to someday get a chance to hunt the Hell Creek area. Even if all I brought back is a few bags of chunkosaurus, that's still different and interesting!

[smt126]

Sounds like a fun trip. Looks like you got some great finds.

[Mediospirifer]

I looked back at my fossil book (Fossils of Ohio, if anyone's interested), to see three species of Platystrophia pictured: P. ponderosa, P. clarsvillensis, and P. cypha. Looking at the website I linked above, all Platystrophia are now Vinlandostrophia--and there are several more species than the three my book shows.

Looking through the pages there, your winged specimen can only be V. cypha. Your second specimen matches V. laticosta, going by the number of plications in your photograph. So, they're both Vinlandostrophia, but different species.

I found an ID for the tubelike encrusting fossil, too, though not in the book. Exploring the website (I searched on Tentaculites and looked at comparison photos) turned up a photo of Cornulitidae, which led to a single species: Cornulites corragatus. I think we have a match!

I didn't find anything in the book that clearly matched the brachiopod in with your Lepidocyclus. Can you take a few more angles (both valves, hinge line, and side profile)? That might help.

Edited June 21, 2016 by Mediospirifer

[erose]

The "other" brachiopod amongst the Lepidocyclus appears to be Hebertella. They are generally very common in the Richmond group.

Go here for so much more: http://strata.uga.edu/cincy/index.html

Edited June 21, 2016 by erose

[digit]

Some great references there--thanks for the links.

I do remember seeing photos of Hebertella online and thinking this could be what it was due to the distinctive triangular pedicle opening. I just double check that specimen and confirmed the hinge and it does seem to be triangular.

Cheers.

-Ken

[Mediospirifer]

erose, that link looks useful! Although I notice it doesn't go into any descriptive details for identifying specimens. Still, a list of all known fossils and their current taxonomy is good to have. I'll be bookmarking that one...

Some great references there--thanks for the links.

I do remember seeing photos of Hebertella online and thinking this could be what it was due to the distinctive triangular pedicle opening. I just double check that specimen and confirmed the hinge and it does seem to be triangular.

Cheers.

-Ken

While the hinge and pedicle opening weren't visble in the photograph.

I notice that the site erose linked has a lot of species listed that aren't shown in any other resource I have. There are several species of Cornulites, for example, and about twice as many Vinlandostrophia species as the other site lists! Positive ID would require a lot of research, although a quick check on Google searching for "Vinlandostrophia corryvillensis" turns up a Smithsonian publication that has the original description, among a lot of others! Available as a free ebook: LINK.

Have fun! I'll eventually catalog all of mine properly, but not right now. For now, the genus is enough.

[digit]

I'll never build a definitive collection of Ordovician fauna (from the Cincinnati area or elsewhere). For me it is enough to learn down to the genus (when possible) to do a little research and learn a bit. Rather than aim for an encyclopedic knowledge of all fossils from all localities and time periods, I'm just happy to push (nay, ever so slightly nudge) the envelope of my current sphere of knowledge as I experience new places to hunt and collect some tidbits. That way my research is always guided by in-hand specimens and I tend to get an education in the more commonly encountered items.

If I get a free moment soon I'll get a photo of the south end of a northbound Hebertella and try to get some better photos of my wrinkly Glyptorthis. See I barely know anything about brachiopods and I can already toss about genera like I know what I'm doing.

Thanks to all for the education along the way. Hoping some others who might collect in southeastern Indiana may find this topic useful over the years.

Cheers.

-Ken