Wooster and Ohio State Paleontologists in Tallinn, Estonia

August 8th, 2018

Tallinn, Estonia — This morning Bill Ausich (Ohio State University) took the bus from Tartu to Tallinn to finish one more research task and then prepare for the long journey home. Above is the view from my hotel room towards the Old City section of Tallinn.

After getting settled, we visited Ursula Toom at the Department of Geology, Tallinn University of Technology. She and Bill (above) exchanged crinoids, and then Ursula discussed with me a wide variety of Ordovician borings as part of her dissertation work.

This is a small part of the various mystery specimens Ursula shared with me. There are some fantastic undescribed borings in this lot.

Afterwards Bill and I had an early evening dinner in the Old City, beautiful in the setting sun.

Our research in Estonia is done! Tomorrow we pack up and then walk around Tallinn taking in the sights and culture. On Friday we fly home. I hope to describe the results of our work soon in this blog.

Last day at the Tartu Natural History Museum, and a visit to a grim museum

August 7th, 2018

Tartu, Estonia — Bill Ausich and I started our last full day in this city at the University of Tartu Natural History Museum, finishing our work with the marvelous Mare Isakar, pictured above. Mare quickly found the specimens we needed, and many others she knew we would find interesting. She did nearly instant registration of specimens, greatly speeding up our taxonomic progress.

We finished photographing museum specimens for our future reference and possible publications. Bill concentrated on Silurian crinoids and I worked on the Ordovician rhombiferan Echinosphaerites.

This is one of Öpik’s Echinosphaerites aurantium specimens. Two roundish encrusting brachiopods are visible, along with sheet-like bryozoans. Shockingly, there are gouges in the bryozoans as if someone tried to scrape them off!

Most of the rhombiferans are filled with sediment and/or calcite crystals, but Bill found this hollow one in the collections. Note that it was still able to resist sedimentary compaction. Also note the bryozoans on the broken edge.

This broken specimen shows sediment in the bottom of the skeleton and crystals in the top half. This is known as a geopetal structure where the sediment shows what was the lower part of the skeleton when it was filled. Here’s another example.

Mare found even more specimens of Echinosphaerites today, so there is much to do on a later trip! Thank you again to Mare Isakar and our other friends in Tartu. Tomorrow we travel to Tallinn for a bit more work before heading home on Friday.

And now for something darker — the KGB Cells Museum in Tartu. It is a horrifying place of pain, anguish and hopelessness, yet today is surrounded by a vibrant, free city and country. This museum, in an actual KGB prison, is both disturbing and ultimately inspiring. It is a history we avoid at our peril.

A cell door near the entrance to this basement complex of “the grey house”. These dungeons were used by the Soviet secret police for detention, torture and executions in the 1940s and 1950s. For a brief interval (1941-1944) the Nazis took over and did the same beastly activities. The victims were almost entirely Estonians.

A hallway of cells. The exhibits inside the rooms include many Soviet artifacts, along with stories of Estonian resistance.

A KGB mannikin at the end of a hallway. A sound track of a harsh Russian voice plays in a loop here, along with inevitable screams and moans. The brutality of the place is quite evident enough, thank you.

Finally, before you leave, why not dress up as a Soviet KGB officer and pose with Stalin? I don’t understand why anyone would do such a thing, especially in such a tragic space.

Tomorrow it is back to science as Bill and I take the bus to Tallinn. The countryside of free Estonia is beautiful.

Last day in the University of Tartu Geology Department — and a great garden party

August 6th, 2018

Tartu, Estonia — As a sign we’re near the end of our work in Tartu, there are no crinoids in this post. Instead, above is an Ordovician bryozoan from Estonia that encrusted the aragonitic shell of a nautiloid. The aragonite dissolved away, giving my favorite underside view of a bryozoan attachment from its ancestrula. We’ve seen this more than once in this blog. The bonus here are the just-visible chains of little crystalline teardrops across the surface.

These are the zooids of the cyclostome bryozoan Corynotrypa. They are encrusted right-side-up, meaning that they grew across the exposed attachment surface of the big bryozoan. The nautiloid shell thus dissolved between the two encrusting events — very early on the seafloor. Classic calcite sea dynamics.

After sorting out the specimens used in our crinoid studies, and doing some last microphotography, we finished our work for this season at the University of Tartu Department of Geology. A small and happy garden party followed.

Bill Ausich and some of our Estonian colleagues and friends. From the left is Oive Tinn, Mare Isakar, Bill, and Viirika Mastik. Great conversations. It actually got a little chilly outside, so we ended in Oive’s house (see below).

Sunday at the University of Tartu Natural History Museum — this time as tourists

August 5th, 2018

Tartu, Estonia — Bill Ausich and I returned to the Natural History Museum today to tour the public exhibits. It was hard to not make it into a study trip, though, for our research. I suppose since our “work” is so enjoyable it is difficult to separate it from a holiday. Above, for example, is a display of our favorite rhombiferan, Echinosphaerites aurantium of the Estonian Upper Ordovician.

There is a display about the Kalana Lagerstätte that we are studying.

Here is the museum description of the Lagerstätte.

And a close-up of some crinoids (“meriliilia”, sea lilies) from the Kalana.

It is a fun museum with a very thorough geology section, including meteorites you can touch (a favorite of mine). It has what is now an old-fashioned style of emphasizing actual specimens that Bill and I appreciated. There is a large biology section with much taxidermy and mounted skeletons. One of the featured exhibits is a rare “rat king” (see below), which you must look up!

Starting work in the University of Tartu Natural History Museum

August 2nd, 2018

Tartu, Estonia — Today Bill Ausich and I began our work in the University of Tartu Natural History Museum. Our most knowledgeable and helpful host is chief geology curator Mare Isakar. This museum is just a short walk from our hotel.

This is one of the collections rooms in the paleontological research part of the museum. Here is where I examined Ordovician bivalves and gastropods for bryoimmurations.

One of our goals is to study encrusters on specimens of the nearly spherical Late Ordovician rhombiferan echinoderm Echinosphaerites aurantium. Mare Isakar kindly set out dozens of specimens for us to study, a small subset of which is shown above.

Here is Bill at work scanning through a drawer of Echinosphaerites.

One of the encrusted Echinosphaerites skeletons. The black, branching, carbonaceous encruster is the graptolite Thallograptus sphaericola (“sphere-dweller”).

Posted in the museum is this figure by Öpik (1925) showing his idea of an Echinosphaerites community with encrusting graptolites. We want to test his hypothesis that the graptolites encrusted living rhombiferans as shown. My hypothesis is that the graptolites lived instead on dead, cemented skeletons. Armin Aleksander Öpik (1898-1983) was a prominent and productive Estonian paleontologist. Like many Estonian scientists of his generation, his career was bifurcated by World War II.

Several characters from Estonia’s scientific past watched us work. This is Constantin Grewingk (1819-1887). Ohio paleontologists will recognize him as the namesake of the rugose coral Grewingkia.

Here is Friedrich Schmidt (132-1908), considered the founder of Estonian geology. Both Grewingk and Schmidt were Baltic Germans.

The public part of the museum includes this exhibit on “Secrets of Ancient Sea”. You may recognize some familiar Ordovician characters in this scene. Bill and I intend to visit the public exhibits here on Sunday.

Thank you again to Mare Isakar for setting us up so efficiently for our research!

Wooster Geologists on Helvellyn

June 4th, 2018

The black mountain icon indicates the location of Helvellyn in the Lake District.

During the last two weeks of May, Dr. Alley and were in the UK.  Part of the experience involved complaining about the inadequate width of UK roads, but there was also some undeniably beautiful geology.  One such location was Helvellyn, in the Lake District of England. This is one of the “top walks” in the UK, but note that the term “walk” has a very loose definition in British English.  Really, this is a hike, with a climb of nearly 3000 ft in about 4 mi.  If you’re a fan of glacially carved, open landscapes, it deserves the hype. 

The exposed rocks of the Helvellyn Range are part of the Borrowdale Volcanic Group. The volcanics here transitioned from primarily intermediate lava flows (andesite) to more silica-rich magma that resulted in pyroclastic flows and ignimbrite deposits.  This all occurred around 450 million years ago (Ordovician) — around the same time as the Taconic Orogeny in North America (most notably in New England).

That’s the raw material for the terrain, but the carving is much more recent.  Glaciers from the last glacial advance have gouged out the sides of these mountains into deep u-shaped troughs with steep sides and wide bottoms. Below Helvellyn sits a deep bowl called a cirque. This is where a large mountain glacier once originated, digging out a hole from which it later advanced.

Look back at Helvellyn Cirque from Birkhouse Moor.

If you go up into the cirque today, that depression has been filled with a small lake called a tarn. Tarns sits at the headwaters of watersheds, and the outlets are often some of the cleaner water you can find (although they may be turbid from lots of sediment).  This tarn, though, had a large number of sheep around it.  So I’d be a little more suspicious.

Red Tarn below Helvellyn.

Actually, the sheep are a more important aspect the the geology than you might think.  Looking down from Helvellyn, you can see the “Striding Edge”.  This is an arête, a sharp ridge that, thousands of years ago, was the boundary between two parallel glaciers.  The glaciers would have been flowing away from you in the image below.

View eastward from Helvellyn overlooking Striding Edge (an arête) and Red Tarn.

Finally, when walking along the northwest side of the mountain, you go by the Greenside Mine. In the 19th century, veins along a normal fault through the mountain were mined for the mineral galena (PbS), which also contains impurities of silver. 

New article: Paleoecology of an Upper Ordovician submarine cave-dwelling bryozoan fauna and its exposed equivalents in northern Kentucky, USA

April 20th, 2018

I’m happy to link to an article on Ordovician bryozoans that has just appeared in the Journal of Paleontology:

Paleoecology of an Upper Ordovician submarine cave-dwelling bryozoan fauna and its exposed equivalents in northern Kentucky, USA

It is work Caroline Buttler (Head of Palaeontology at the National Museum Wales, Cardiff) and I pursued as our first joint project. An early version is described in this blog post. Thank you to Caroline for her leadership, and the Luce Fund at The College of Wooster for its support. If you want a pdf of the paper, just send me an email note.

[I just noticed this is my 1000th post on this blog!]

A Wooster Paleontologist visits the Smithsonian’s National Museum of Natural History

April 5th, 2018

Washington, DC — I have the privilege this semester of being on a research leave from teaching, so I thought I’d report on one of my activities. Without classroom responsibilities I can travel for research opportunities, especially now as the weather in the northeastern US marginally improves. (Despite the sunny view above, it was freezing!)

I visited the Paleobiology Department of the National Museum of Natural History in Washington to examine some particular fossils in the collections, and give a departmental seminar. This is typical for paleontological research, and I’m grateful to the generations of museum scientists who make it possible.

The Collections Manager at the NMNH Paleobiology Department is our own Kathy Hollis (’03). She does such a fine job she’s on a poster board in front of the museum, and she was featured in an excellent Wooster Magazine article on museum science.

Kathy sets me up deep in the fossil collections, endless rows of cabinets. The Paleobiology Department, in fact, has more than 10,000 of these, each with multiple drawers of treasures.

My work is pretty simple at this stage. I find fossils of interest in the collections (most of which I’ve identified from publications) and photograph them for future reference. I use this copy stand, which is the best in the business. (I want one, Department Chair.) The paper tray is filled with lead shot which is useful for positioning specimens at any angle under the camera.

Here’s an example specimen: the ambonychid bivalve Claudeonychia from the Upper Ordovician of the Cincinnatian region. The scale is in centimeters. The dark color is actually an encrusting bryozoan, a story I’ll tell later.

I meet many cool fossils along the way, including this magnificent specimen of Wilsonoceras from Wyoming. It is a nautiloid cephalopod I’ve always wanted to see purely for its name!

Here is the poster for my presentation to the Paleobiology Department. It is a tradition for visiting researchers to present a talk on their work.

This is the Cooper Room where the talks are held. I love its Old School ambiance, and the paleontological history it represents. It is a superb place to present ideas to colleagues in the discipline.

The field season is about to begin for Wooster Earth Scientists, so expect more posts. Again, it is a privilege to have such opportunities.

Wooster’s Fossils of the Week: Encrusting cyanobacteria from the Upper Ordovician of the Cincinnati region — now published

November 17th, 2017

1 pdt19598 D1253[This week’s post is a repeat from last year, with some modifications. The paper Paul Taylor and I wrote on these microbial beauties has just appeared this week in the latest issue of the journal Palaios. A pdf is yours if you send me an email message.] Update: The paper is now a cover story.

Deep in the basement of the Natural History Museum in London, Paul Taylor and I were examining cyclostome bryozoans encrusting an Upper Ordovician brachiopod with a Scanning Electron Microscope (SEM). This is one of our favorite activities, as the SEM always reveals tiny surprises about our specimens. That day the surprises were the smallest yet – fossils we had never seen before.

2 Infected brachWe were studying the dorsal exterior surface of this beat-up brachiopod from a 19th Century collection labelled “Cincinnati Group”. (Image by Harry Taylor.) We knew it was the strophomenid Rafinesquina ponderosa, and that the tiny chains of bryozoans encrusting it were of the species Corynotrypa inflata. We’ve seen this scene a thousand times. But when we positioned the SEM beam near the center of the shell where there was a brown film …

3 pdt16920 D1253… we saw that the bryozoans were themselves encrusted with little pyritic squiggles. These were new to us.

4 pdt19580 D7139In some places there were thick, intertwining mats of these squiggles. We later found these fossils on two other brachiopod specimens, both also Rafinesquina ponderosa and from 19th Century collections with no further locality or stratigraphic information.

5 pdt19578 D7139Paul and I scanned these specimens again and began to put together an analysis. We believe these are fossil cyanobacteria. They are uniserial, unbranching strands of cells that range from 5 to 9 microns in length and width. Some of individual strands are up to 700 microns long and many are sinuous. The cells are uniform in size and shape along the strands; there are no apparent heterocysts. They appear very similar in form to members of the Order Oscillatoriales.

6 CyanobacteriaCyanobacteria are among the oldest forms of life, dating back at least 2.1 billion years, and they are still abundant today. The fossils are nearly identical to extant forms, as seen above (image from: http://www.hfmagazineonline.com/cyanobacteria-worlds-smallest-oldest-eyeball/).

7 pdt19599 D1253Paul made this remarkable image, at 9000x his personal record for high magnification, showing the reticulate structure preserved on some of the fossil surfaces. Note that the scale bar is just 2 microns long. These are beautiful fossils in their tiny, tiny ways.

We have not seen these cyanobacteria fossils before on shell surfaces, so we submitted an abstract describing them for the Geological Society of America annual meeting in Denver this September. We are, of course, not experts on bacteria, so we are offering our observations to the scientific community for further discussion. Here is the conclusion of our abstract —

“We suggest the cyanobacterial mats developed shortly before final burial of the brachiopod shells. Since the cyanobacteria were photosynthetic, the shells are inferred to have rested with their dorsal valve exteriors upwards in the photic zone. That Cincinnatian brachiopod shells were occupied by cyanobacteria has been previously well demonstrated by their microborings but this is the first direct evidence of surface microbial mats on the shells. The mats no doubt played a role in the paleoecology of the sclerobiont communities on the brachiopods, and they may have influenced preservation of the shell surfaces by the “death mask” effect. The pyritized cyanobacteria can be detected with a handlens by dark squiggles on the brachiopod shells, but must be confirmed with SEM. We encourage researchers to examine the surfaces of shells from the Cincinnatian and elsewhere to find additional evidence of fossilized bacterial mats.”


Noffke, N., Decho, A.W. and Stoodle, P. 2013. Slime through time: the fossil record of prokaryote evolution. Palaios 28: 1-5.

Tomescu, A. M., Klymiuk, A.A., Matsunaga, K.K., Bippus, A.C. and Shelton, G.W. 2016. Microbes and the Fossil Record: Selected Topics in Paleomicrobiology. In: Their World: A Diversity of Microbial Environments (pp. 69-169). Springer International Publishing.

Vogel, K. and Brett, C.E. 2009. Record of microendoliths in different facies of the Upper Ordovician in the Cincinnati Arch region USA: the early history of light-related microendolithic zonation. Palaeogeography, Palaeoclimatology, Palaeoecology 281: 1-24.

Wilson, M.A. and Taylor, P.D. 2017. Exceptional pyritized cyanobacterial mats encrusting brachiopod shells from the Upper Ordovician (Katian) of the Cincinnati, Ohio, region. Palaios 32: 673-677.

Wooster’s Fossils of the Week: “Ghosts” in the Upper Ordovician of Kentucky

October 13th, 2017

This year Caroline Buttler (Department of Natural Sciences, Amgueddfa Cymru – National Museum Wales) and I had a great project describing a cave-dwelling fauna in the Upper Ordovician of northern Kentucky. We hope that work will appear soon in the Journal of Paleontology. During our lab studies of thin-sections and acetate peels of massive trepostome bryozoans, we found several examples of clear calcite bodies in the middle of sediment-filled borings. These structures were described from the Ordovician of Estonia as “ghosts” of soft-bodied organisms by Wyse Jackson and Key (2007). They appear to be mineralized casts of organisms that were buried when sediment filled the borings that they occupied.

Meanwhile, Luke Kosowatz (’17) has a senior Independent Study project assessing bioerosion in the Upper Ordovician of the Cincinnati area. He and I have also found numerous examples of these ghosts in borings, so many that they have become a phenomenon in themselves for study. Above is an acetate peel made tangentially to the bryozoan surface showing the numerous tubular zooecia punctured by a few larger borings. Most of these borings are filled with sediment, but the two indicated by the arrows have these calcitic ghosts. This specimen is from the Corryville Formation near Washington, Mason County, Kentucky (38.609352°N latitude, 83.810973°W longitude; College of Wooster location C/W-10).

Above is one of our many heavily-bored trepostome bryozoans. This one comes from the Bellevue Formation (Katian) exposed on Bullitsville Road near the infamous Creation Museum (C/W-152). The irregular holes are the cylindrical boring Trypanites. The ghosts are not visible without sectioning.

Here is a close view of one of the ghostly calcitic casts in an acetate peel. The boundaries are sharp between the ghosts and the surrounding sediment.

The arrows above show ghosts in longitudinal cross-sections. Note their extended oval shapes. These are clearly organic shapes under these circumstances. (This is a thin-section.)

So what do the ghosts represent? They could be remains of the boring organisms themselves. If they are, they can be used to address a problem we have with bioerosion: What is the temporal relationship between the borings? How many were active in a given substrate at a given time? The percentage of borings with ghosts may give us a minimum amount of contemporary bioerosion. If, again, these are remnants of the borers themselves.

Maybe the ghosts are of later organisms that occupied the borings after the borers died? This happens often, with the secondary inhabitants called nestlers.

I know of no way to sort possible borers from nestlers with this kind of evidence.

The above image shows it’s possible that some of the ghosts are of organisms that had shells. The arrow is pointing to a dark line that may represent the remains of some type of shell. I’ve seen little tiny lingulid brachiopods in some borings before.

A fun mystery!

For technical interest, here is our photomicroscope we use to produce images like those in this post.


Cuffey, R.J. 1998. The Maysville bryozoan reef mounds in the Grant Lake Limestone (Upper Ordovician) of north-central Kentucky, in Davis, A., and Cuffey, R. J., eds., Sampling the layer cake that isn’t: the stratigraphy and paleontology of the type-Cincinnatian. Ohio Department of Natural Resources Guidebook 13: 38-44.

Wyse Jackson, P.N. and Key, M.M. Jr. 2007. Borings in trepostome bryozoans from the Ordovician of Estonia: two ichnogenera produced by a single maker, a case of host morphology control. Lethaia 40: 237-252.


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