Wooster’s Fossil of the Week: A strange little echinoderm (Ordovician of Russia)


This small fossil was completely new to me when I found it during my research trip to the Ordovician of Russia in the Fall of 2009.  A side view is shown on the left of this conical skeleton, and the top view is right.  I could tell it was an echinoderm because it has a characteristic structure in its calcitic skeleton known as the stereom (a network of tiny passageways inside the crystals).  Other than that, it was a mystery to me.

My Russian colleague Andrey Dronov showed me that it is of the genus Bolboporites, a strange relative of the crinoid found only in the Ordovician of the Baltic Region and North America.  As you can see in the reconstruction on the right below, it probably lived in the sediment as an upwardly-flaring cone with a single feeding arm (the brachiole) collecting suspended organic matter from passing water for food.  In the fossil view above and right, you can see the hole where the missing brachiole fit; inside of that you can just make out an opening that is likely the mouth.

Bolboporites likely originated on the paleocontinent of Baltica and then migrated to North America.  As far as I can tell it is vanishingly rare over here — I’ve never seen Bolboporites before in the field or in collections.  Now Wooster has one of the very few of these little treasures.

References —

Rozhnov, S.V. 2009. Eocrinoids and paracrinoids of the Baltic Ordovician basin: a biogeographical report. IGCP Meeting, Ordovician palaeogeography and palaeoclimate, Copenhagen, p. 16.

Rozhnov, S.V. and Kushlina, V.B. 1994. Interpretation of new data on Bolboporites Pander, 1830 (Echinodermata; Ordovician), p. 179-180, in David, B., Guille, A., Féral, J.-P. & Roux, M. (eds.), Echinoderms through time (Balkema, Rotterdam).

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Wooster Tree Ring Lab Ready for Business

Guest blogger Jon Theisen

Beginning May 17th and running until June 10th, the College of Wooster Tree Ring Lab has been partnering with and funded by The Center for Entrepreneurship in an effort to demonstrate the viability of dendrochronological dating as a business opportunity.   The professor in charge of the Tree Ring Lab, Greg Wiles, and his employees, Jon Theisen and Anna Mudd, have spent the last four weeks collecting and dating samples gathered from the towns of Worthington and Somerset, Ohio.  The first week of the project consisted of traveling to the towns of Worthington and Somerset, which are approximately two hours south of Wooster.

Greg Wiles and Jon Theisen consulting with Somerset Mayor Tom Johnson in the Ridenour Barn, one of the many structures sampled by the Wooster Tree Ring Lab

On Tuesday, May 17th, members of the Tree Ring Lab traveled to Worthington, Ohio, in order to sample two structures for the Worthington Historical Society.  The first structure was the Old Rectory, which the Tree Ring Lab successfully dated to 1846.  The Old Rectory was built to house the reverends of St. John’s Episcopal Church.

In the afternoon, members of the Tree Ring Lab went to the Orange Johnson House, just a quick drive from the Old Rectory, in order to gather tree ring samples.  The Orange Johnson House was successfully dated to 1811 for the original structure.

The next day, researchers traveled to Somerset, Ohio, to meet with the Mayor, Tom Johnson.  Mayor Johnson had a number of structures that he wanted dated, so the Tree Ring Lab got to work.

The front of the Miller Tavern in Somerset, Ohio.  Although the exterior of the building has been renovated, the interior beams of the building are still original.

The first building the team sampled in Somerset, Ohio, was the Miller Tavern.  The image above is of team member Jon Theisen using a hand auger to retrieve a wooden core sample from a wall beam in Miller Tavern.  The Miller Tavern was successfully calender dated to 1808.

The team spent Thursday, May 19th in the Tree Ring Lab becoming familiar with the equipment and computer programs they would use to date the cores retrieved from the structures we sampled.  Below is an image of what the retrieved cores look like after they have been sanded and mounted.

The retrieved cores are glued into wooden mounts, and then sanded with a belt sander and high grit sandpaper until they are very smooth and the individual rings can be seen under the microscope.  The cores are counted and the total number of years represented by individual rings is written on the side of the mount.  After the initial count is completed, the cores are placed on the Acu-Rite measuring system, and by using a computer program called Measure J2X, the width of the individual tree rings is measured to the nearest 0.001mm.  These measurements are saved to a computer file where they can then be edited.  A computer program called COFECHA is then used to compare the ring width data of cores taken from a single structure against each other to create a “floating” chronology where the cores are relatively dated against one another.

An example of how cores can be dated relative to each other in order to develop a “floating” chronology

Once a “floating” chronology has been developed for a structure, the ring width measurements are compared against a calendar dated master series of measurements that have been previously dated.  By comparing the “floating” chronology against the master series, a calendar date can be assigned to the structure.

After a day in the lab, the team was ready to get back out in the field and continue gathering samples.  Friday, May 20th saw members of the Tree Ring Lab return to Somerset, Ohio, to gather samples from more structures off of Mayor Tom Johnson’s list.  In the morning the team stopped at the Linnabary House, pictured below, to take a sample.  According to the owners, the house was originally used as a church.  The beam was successfully dated to 1823.

In the afternoon, the team collected samples from two structures.  The first building was the historic library of Somerset, which was still in use today.  The team went down to the basement of the library, pictured below, and gathered samples from the joists supporting the floor.  The library was successfully dated to 1818.

After the library, the team traveled into the country and visited the Johnson House, pictured below.  While the building had been damaged by recent storms that downed trees, Tom Johnson is hoping that a date for when the structure was built will help secure funds for rehabilitating the structure.  The Johnson House was calendar dated to 1817.

 

After the first week in the field, the team spent the following three weeks in the Tree Ring Lab sanding, counting, and dating cores.  During this time, Jon Theisen and Anna Mudd created seven reports detailing the findings for each structure, a poster, and a blog post.  The reports consist of the name of the structure, a description of the dating techniques used, the calendar date of the samples, and a graph showing how well the measured samples correlate with the master series they were dated against.

These four weeks have shown members of the Tree Ring Lab that there is a great demand for dendrochronological dating.  Dr. Wiles has continued to receive requests for the Tree Ring Lab to visit sites across Ohio in order to gather samples and provide dates for historic structures.

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Wooster geologists in the heart of American science

ARLINGTON, VIRGINIA–The National Science Foundation (NSF) is a federal agency charged by Congress “to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense…” It had a budget last year of $6.9 billion and is a major source of funding for American scientific research, especially in colleges and universities. NSF is highly respected — and not a little feared — by working scientists. I visited NSF headquarters in Arlington, Virginia, for a meeting with Lisa Park Boush (Wooster ’88) who is a Program Director for Sedimentary Geology and Paleobiology. Although we were not discussing NSF business (we were transferring the Secretary position of The Paleontological Society from her to me), I learned a lot about the agency from Lisa. NSF officials work very hard, for one, and they are very concerned about the scientific communities they serve.

The impressive front of the NSF building in Arlington, Virginia.

Lisa Park Boush in her NSF office (with a coveted window view behind her). Lisa was one of my Independent Study students, so I am especially proud of her accomplishments and responsibilities.

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Wooster Geologist in … a library

WASHINGTON, D.C.–And not just any library — The Library of Congress. I am in the Thomas Jefferson Building, the front of which is shown above. In the heart of the Jefferson complex is the Main Reading Room (see below), where I’m occupying a desk in one of the concentric circles for readers. To get in I had to preregister as a researcher online and then file an application to receive a cool Reader’s Identification Card with my picture on it. I’m also demonstrating a fact about scientific research: for every hour spent in the field or lab, at least ten are required staring at a computer screen.

The Main Reading Room is extraordinary. It is circular with a giant dome above and a balcony level lined above with allegorical Greek female plaster statues 10 feet high symbolizing Religion, Commerce, History, Art, Philosophy, Poetry, Law and Science. Just below is a ring of 16 life-size bronze statues of Famous Men (all men) who led lives of thought and, I suppose, reading. (Unlike in Wooster’s Timken Science Library, Darwin does not make the cut.) It is a very impressive place to be a scholar, although every cough and sneeze echoes mightily through here.

The Main Reading Room in the Jefferson Building of the Library of Congress. Photography is not allowed in here, so this image comes from the Library of Congress webpage (http://www.loc.gov/index.html).

The Library of Congress was established in 1800 when the capitol of the United States moved from Philadelphia to Washington, D.C. The British burned it in 1814 during that regrettable little War of 1812, but Thomas Jefferson stepped up and presented his personal library to the nation as a replacement. It is now the largest library in the world counting books and shelf space.

I am here to get some writing done. My main mission in Washington this week is to see Lisa Park in the National Science Foundation headquarters (more on that later), but I’m spending a good two days of the visit writing a draft of a manuscript. I need a place to write with an internet connection, few distractions, and a sense of formality. No place is more formal, scholarly or serious than this!

The collections here are primarily for the humanities and social sciences. This is not a problem for me because all the resources I need are electronic and only a few clicks away. Plus I don’t feel lonely here as a scientist because this good man is  looking down on me:

From: http://www.loc.gov/index.html

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Wooster’s Fossil of the Week: Coated snails! (Middle Jurassic of France)

In 1988 I had my first visit to France, hosted by my English friend Tim Palmer. We explored Bathonian (Middle Jurassic) limestones in Normandy tracking looking at hardgrounds and other hard substrates. Along the way we stopped in a quarry near the pretty little town of Aubry-en-exmes. There we found thousands of cylindrical white stones. Where broken, we could see they contained some sort of fossil in the center. When I got back to Wooster I cut a few open and polished them down to their centers, revealing the gorgeous snail shells seen above. The shells were originally the mineral aragonite now replaced with coarsely-crystalline calcite.

The snail is known as Bactroptyxis trachaea of the extinct Family Nerineidae in the informal group “Lower Heterobranchia” (which is still around). Cross sections of nerineids like this show their most distinctive feature: elaborate chamber walls inside the whorls of the shell (as seen in a close up below). It was once thought that these complicated structures evolved to strengthen the shell against shell-crushing predators, but now the most common view is that they held special digestive glands to enable them to exploit nutrient-poor organics on carbonate substrates (Barker, 1990).

There is another fossil type here as well: the thick, white calcareous coating of the snails. These are oncolites, a precipitate formed by cyanobacteria. The shells rolled around in a current as the bacteria added layer after layer of calcium carbonate, preserving the shells in such fine detail — and by the thousands.

Reference —

Barker, M.J., 1990. The palaeobiology of nerineacean gastropods. Historical Biology 3: 249-264.

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A gecko’s end

MITZPE RAMON, ISRAEL–What is Will examining so intently? There was drama on the outcrop this afternoon. We are used to seeing cute little geckos clinging to the rocks we study. As we skirted the edge of a limestone cliff, Will saw a very long and narrow snake dash after a lizard. We all watched as the lizard dived down the rocks of the cliff, scrambling to the bottom. The snake followed its every move, catching it in a talus pile. The circle of life.

You can see the snake’s coils here and a motionless lizard. Why is he holding so still in such a dangerous place?

Because on closer view we see that the snake has him by the head and has started to slowly swallow him.

This encounter reminds me of the lizard-scorpion battle witnessed by the 2010 Wooster Geologists team in Utah.

This was our last field day in Israel. Tomorrow morning, very early (4:00 a.m.!), we start the long drive north to Tel Aviv and Ben Gurion airport. Then the long flight to Newark and then Cleveland. It has been another wonderful adventure of geology, biology and history.

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Wooster Geologists at the Siege of Lachish (2700 years later)

MITZPE RAMON, ISRAEL–Every time I visit the British Museum in London, I examine the fascinating relief from Nineveh showing The Siege of Lachish. The detail is extraordinary as the story is told in sequence through dozens of panels. It is a brutal tale of conquest and pillage, giving insights into the heart of an empire long since extinct. Today Will and I visited the archaeological site of Lachish on the way back from Jerusalem. Our friend Yoav gave us an excellent tour — and we were the only people there. The main gate and approach road is shown in the image above.

Lachish was a walled city at the boundary between the hill country and the coastal plain. It is mentioned several times in the Bible, most notably when captured by Joshua from the Canaanites (see Joshua 10: 1-32). The famous Siege of Lachish was in 701 BCE when the Assyrian king Sennacherib sought to conquer the tiny nation of Judea (see II Kings 18). Lachish watched over the coastal plain and the main approaches to Jerusalem.

The city wall on the approach to the main gate. Soldiers marching up the road would have their right sides exposed to this wall. Since they typically carried their shields on their left arms, they are here vulnerable to defending archers at the top of the wall.

The Assyrians did not attack Lachish directly by the main gate. They instead built a siege ramp of stones and wood on the weakest corner of the walled city. They wheeled battering rams and towers up this ramp, eventually breaching the wall despite a counter-ramp attempted by the Judean defenders. This is one of the best preserved siege ramps in the ancient Near East.

A view of the inside of the city showing remnants of the commander’s palace at the highest point.

The view from Lachish into the Judean Hills. Hebron is visible at the top of the distant ridge.

An archaeological controversy (or at least it should be one) is this well in or near the city walls of Lachish. Geologists have shown conclusively that it was a failed well — it did not reach the aquifer (Weinberger et al., 2008). The builders of the well may have thought that all they had to do was penetrate down as far as the wells outside the city to hit water, but those wells were in a perched aquifer of alluvium. The Lachish well is in Eocene chalk. The city may have been running out of water when it was besieged.

It was a privilege to visit such an historic site and have the luxury of a personal guided tour by Yoav.

Reference:

Weinberger, R., Sneh, A. and Shalev, E. 2008. Hydrogeological insights in antiquity as indicated by Canaanite and Israelite water systems. Journal of Archaeological Science 35: 035-3042.

 

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Wooster Geologists at the Center of the World

Our visit to Jerusalem was to meet geologists at the Geological Survey of Israel main complex in the western part of the city. Those discussions went very well and we met new people and learned much. Will and I also took the opportunity to spend a few hours in the Old City. Here are some of the sites. The view above is of the Old City from Mount Scopus.

When we say that Jerusalem is the “Center of the World“, we are following a medieval tradition illustrated by this European manuscript page reproduced as a tiled image at the City Hall.

The Geological Survey of Israel headquarters have a very unassuming (and secure) entrance. This is an old World War II British military base that was on the outskirts of the city but is now surrounded by an Ultra-Orthodox Jewish community. It is a wise move not to advertise the very secular activities going on in there!

Our main walking route from the Survey to the Old City was Jaffa Street, which leads directly to Jaffa Gate. This is looking northwest. There is a new tram system being tested, thus the tracks in the road and lack of cars.

Will in the Old City market on our way to the Church of the Holy Sepulchre.

Outer courtyard of the Church of the Holy Sepulchre. All those people going in and out of that one doorway. Jerusalem now receives a record three million visitors a year.

Turns out the Center of the World is actually within the Church of the Holy Sepulchre … and its exact spot has been marked!

There are very few places in the Church of the Holy Sepulchre where you can see the original bedrock of the area. This is a famous crack in the rock below what is supposed to be the crucifixion site and above what is known as Adam’s Grave. Note the strain gauge across the joint. There are geological concerns about the stability of the bedrock and monumental structures built on top of it. I can’t imagine how the Israeli authorities got religious sanction to install that instrument!

Crepuscular rays descending from the dome of the Church of the Holy Sepulchre. The top of the Holy Sepulchre structure is at the bottom of the image.

Finally, we visited the Western Wall revered in Judaism. Above it (and not visible in this image) are the Islamic holy sites in Jerusalem: the Al Aqsa Mosque and the Dome of the Rock. We thus visited in the space of a few hours sacred spaces of the three Abrahamic religions. Center of the World indeed.

 

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Wooster Geologists return to the Dead Sea

MITZPE RAMON, ISRAEL–Today Will and I went to Jerusalem for meetings at the Geological Survey of Israel headquarters. Much more on that later. On the way Yoav drove us along the west coast of the Dead Sea. Will got a chance to dip his hand in the warm and heavy water, and we talked about salt, shorelines and sinkholes.

These are halite (salt) deposits on the Dead Sea shore near Will’s feet above. Halite encrusts all that this water touches, from rocks and sediment to abandoned tires.

This slope above the highway on the west shore of the Dead Sea shows ancient shorelines from roughly 26,000 to 14,000 years ago. The sea then was salty but only about half the current salinity. Shorelines fluctuated but generally fell during this 12,000 year interval.

A serious environmental problem along the western shore is the development of huge sinkholes. These are forming because the Dead Sea is losing water rapidly (it drops about a meter per year) and freshwater is now finding thick salt deposits underground. The water dissolves the salts, forming caverns that eventually collapse and make the pits above. Often the pits then fill with water, making small ponds that have their own flora and fauna.

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Mishash, b’gosh

MITZPE RAMON, ISRAEL–Today Will and I drove south, east and north to meet Dr. Yael Edelmen-Furstenburg of the Geological Survey of Israel. She gave us a most excellent tour of the Mishash (pronounced ME-shawsh) Formation (Campanian, Upper Cretaceous) in the Wadi Ashosh region (shown above) near Zuqim and Tsofar in the Negev Desert. We talked much about the fossil fauna, particularly the trace fossils in soft and hard substrates. There could be many future Wooster Independent Study projects in this formation, especially here where it is so diverse.

As seen above, much of the Mishash Formation consists of bands of chert. The folds are syndepositional (formed at the time of deposition) as part of the Syrian Arc deformation. This makes for some very interesting local stratigraphy and depositonal patterns.

The Mishash Formation has exquisite fossil shell beds, often silicified (replaced with silica). Above you can see gastropods and bivalves.

An old Cretaceous friend, the ammonite Baculites, is used to sort out the biostratigraphy of the Mishash. They are identified by the style of ribs they have on the outside of the conch.

Like everywhere else in the Negev Desert, shade is a bonus. We always appreciate the acacia trees, even if their shade is not so complete. Will is standing here next to the Geological Survey of Israel vehicle. Shlomo, an old friend and the driver, gave us quite the off-road adventure. Many people pay for such tours!

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