Wooster Geologists in Indiana!

July 28th, 2012

WOOSTER, OHIO–I’ve seen a lot of fossils in my blessedly long time as a paleontologist, and I’ve had the opportunity to study them in many exotic places. I’m often reminded, though, that one of the best preserved and most diverse fossil faunas is in my backyard: the Cincinnati Region. The fossils here from the Upper Ordovician are extraordinary, and they will always be a resource for paleontological research. They’re just plain fun to find, too. There is a reason why so many American paleontologists have educational roots in the Ohio, Kentucky and Indiana area.

Sure, the setting is not always glorious. Instead of castles in the distance, we are often working in roadside ditches, but the fossils are so fascinating that we forget the prosaic American recreational weekend traffic zooming by to local parks, lakes and rivers. In the above image you see Katherine Marenco (’03), Richa Ekka (’13) and Kit Price (’13) today on our first outcrop of the in eastern Indiana just south of Richmond (C/W-148 in our locality system). It is an outcrop of the Whitewater Formation (Richmondian, Upper Ordovician) known by many Wooster geologists from paleontology course field trips to Indiana. It is chock-jammy-full of fossils, as you can see from the random shot below:

We are here today to collect material for Kit Price’s Junior (and then Senior) Independent Study project. She will be studying bioimmuration processes in these rocks. We will have more on her study after we unpack and clean the treasures we collected today.

Accompanying us on this field trip is Dr. Katherine Nicholson Marenco (Wooster ’03), shown above. She is visiting to Wooster to renew work on Jurassic bioimmuration and aragonite dissolution in the Portlandian of southern England, the topic of her Senior Independent Study in 2002-2003. She went on to graduate school and a post-doc position and is now at Bryn Mawr in Pennsylvania. We are very fortunate to have her with us because of her expertise on the topic of “upside-down encrusters” and her many creative ideas. We look forward to much collaboration! (You can see her in this old page on Paleontology at Wooster.)

Richa Ekka (above) generously volunteered to help us find and collect fossils. You may remember Richa from her very recent work in Estonia. (It is difficult to believe that just two weeks ago we were on islands in the Baltic.) Richa, as always, found great specimens.

Here is Kit working on our last Cincinnatian outcrop near Brookville, Indiana (C/W-111). Note the very dry grass, a result of the continuing drought in this part of the state. The temperatures today, by the way, were in the pleasant high 60s and low 70s.

Finally, we just had to share a photograph of our rented field vehicle: a Dodge Avenger. We think this is the trendiest car color of 2012: burnt pumpkin.

More in later posts on what we found on this field trip, and Kit’s developing Independent Study project. It was a spectacular field day with excellent fossils and great conversations.

Wooster’s Fossil of the Week: A cornulitid (Late Ordovician of Indiana)

December 18th, 2011

This may look like just another wormtube on a shell — a recurring theme on this blog — but it is special, of course. This is the common Paleozoic genus Cornulites Schlotheim 1820, specifically Cornulites flexuosus (Hall 1847). It was found in the Whitewater Formation (Upper Ordovician) during a College of Wooster field trip to southeastern Indiana.

Above is a larger view of the substrate for this wormtube: the ventral valve exterior of a strophomenid brachiopod. If you look closely at the costae (fine radiating lines) of the brachiopod you can see that it was alive when the cornulitid landed on its shell. As both animals continued to grow, the wormtube bent toward the commissure (opening) of the brachiopod, no doubt to snatch some suspended food from its feeding current. The cornulitid was thus a parasite on the host brachiopod. (See Morris and Rollins, 1971; Vinn and Mutvei, 2005; and Vinn and Wilson, 2010, for much more detail on cornulitid paleoecology.)

Suggested cornulitid internal anatomy (from Olev Vinn).

Cornulitids (Ordovician – Carboniferous) belong to a large group of tube-dwelling organisms that, surprisingly, may be closely related to brachiopods and bryozoans. Cornulitids, along with fellow tube-dwellers the microconchids, tentaculitids and hederelloids, have a foliated shell ultrastructure with various other features indicating they may be part of a larger group called the lophophorates (see Taylor et al., 2010). Much work still needs to be done on their systematics and paleoecology to sort out the evolutionary relationships here, but we have a good start.
The genus Cornulites was described and named by Ernst Friedrich, Baron von Schlotheim (1764-1832), a German palaeontologist and politician born in Almenhausen, Thuringia, Germany. As a noble, he was home-schooled (as we’d say now) and then sent to the Gymnasium (like a high school) in Gotha, Germany. After graduation, he attended Göttingen where he studied political administration and the natural sciences with Johann Friedrich Blumenbach. He enjoyed geology very much and so went off to Freiburg to learn from the famous Abraham Gottlob Werner of Neptunist fame. One of his friends was the scientist-explorer Alexander von Humboldt. After this extraordinary education, Schlotheim entered the civil service in Gotha in 1792, eventually rising all the way up to Lord High Marshal a few years before his death. During his administrative work, though, he continued serious paleontological studies, being one of the first paleontologists to use Linnean binomial nomenclature, making fossils much more useful for stratigraphy and later evolutionary studies. Schlotheim had some very progressive ideas about what we would later call uniformitarianism, and he recognized that geology could tell a history of the Earth quite different from that outlined by theological scholars.

Here’s to the intellectual innovations and courage of Baron von Schlotheim and the little fossil wormtube that reminds us of him!

References:

Morris, W. R., and H. B. Rollins. 1971. The distribution and paleoecological interpretation of Cornulites in the Waynesville Formation (Upper Ordovician) of southern Ohio. The Ohio Journal of Science 71: 159-170.

Schlotheim, E.F. von. 1820. Die Petrefakten-Kunde auf ihrem jetzigen Standpunkte durch die Beshreibung seiner Sammlung versteinerter und fossiler Ueberreste des their-und Planzenreichs der Vorwelt erlaeutert. Gotha, 437 p.

Taylor, P.D., Vinn, O. and Wilson, M.A. 2010. Evolution of biomineralization in ‘lophophorates’. Special Papers in Palaeontology 84: 317-333.

Vinn, O. and Mutvei, H. 2005. Observations on the morphology and affinities of cornulitids from the Ordovician of Anticosti Island and the Silurian of Gotland. Journal of Paleontology 79: 726-737.

Vinn, O. and Wilson, M.A. 2010. Abundant endosymbiotic Cornulites in the Sheinwoodian (Early Silurian) stromatoporoids of Saaremaa, Estonia. Neues Jahrbuch für Geologie und Paläontologie 257: 13-22.

Wooster’s Fossil of the Week: an orthid brachiopod (Upper Ordovician of Indiana)

November 27th, 2011

This beautiful brachiopod is Vinlandostrophia ponderosa (Foerste, 1909), an orthid brachiopod from the Maysvillian (Upper Ordovician) of southern Indiana. Until recently it had been traditionally known as Platystrophia ponderosa until a critical paper by Zuykov and Harper (2007) investigated the “Platystrophia plexus” of species and convincingly made P. ponderosa the type species of Vinlandostrophia.

Brachiopods are filter-feeding, bivalved marine invertebrates who have been with us since the Cambrian Period. They were among the most common animals of the Ordovician. The fossils of the Cincinnatian Series in southern Indiana, southwestern Ohio and northern Kentucky have extraordinary numbers and varieties of fossil brachiopods — so many they roll under your feet in some places.

August F. Foerste (1862-1936) described what he called Platystrophia ponderosa in 1909. He was a pioneering paleontologist who grew up and worked in the Dayton area. Foerste went to Denison University where he was a very successful undergraduate, publishing several geological papers. He returned to Dayton after graduation with a PhD from Harvard, teaching high school for 38 years. When he retired he was offered a teaching position at the University of Chicago, but instead went to work at the Smithsonian Institution until the end of his life.

This is, by the way, the 500th post of the Wooster Geologists blog. It is great fun.

References:

Foerste, A.F. 1909. Preliminary notes on Cincinnatian fossils. Denison University, Scientific Laboratories, Bulletin 14: 208-231.

Zuykov, M.A. and Harper, D.A.T. 2007. Platystrophia (Orthida) and new related Ordovician and Early Silurian brachiopod genera. Estonian Journal of Earth Science 56: 11-34.

Wooster’s Fossil of the Week: A Conulariid (Lower Carboniferous of Indiana)

July 31st, 2011

I have some affection for these odd fossils, the conulariids. When I was a student in the Invertebrate Paleontology course taught Dr. Richard Osgood, Jr., I did my research paper on them. I had recently found a specimen in the nearby Lodi City Park. It was so different from anything I had seen that I wanted to know much more. I championed the then controversial idea that they were extinct scyphozoans (a type of cnidarian including most of what we call today the jellyfish). That is now the most popular placement for these creatures today, although I arrived at the same place mostly by luck and naïveté. (I love the critical marks in that word! And yes, I always have to look them up.)

The specimen above is Paraconularia newberryi (Winchell) found somewhere in Indiana and added to the Wooster fossil collections before 1974. (The scale below it is in millimeters.) A close view (below) shows the characteristic ridges with a central seam on one of the sides.
Conulariids range from the Ediacaran (about 550 million years ago) to the Late Triassic (about 200 million years ago). They survived three major extinctions (end-Ordovician, Late Devonian, end-Permian), which is remarkable considering the company they kept in their shallow marine environments suffered greatly. Why they went extinct in the Triassic is a mystery.

The primary oddity about conulariids is their four-fold symmetry. They had four flat sides that came together something like an inverted and extended pyramid. The wide end was opened like an aperture, although sometimes closed by four flaps. Preservation of some soft tissues shows that tentacles extended from this opening. Their exoskeleton was made of a leathery periderm with phosphatic strengthening rods rather than the typical calcite or aragonite. (Some even preserve a kind of pearl in their interiors.) Conulariids may have spent at least part of their life cycle attached to a substrate as shown below, and maybe also later as free-swimming jellyfish-like forms.

It is the four-fold symmetry and preservation of tentacles that most paleontologists see as supporting the case for a scyphozoan placement of the conulariids. Debates continue, though, with some seeing them as belonging to a separate phylum unrelated to any cnidarians. This is what’s fun about extinct and unusual animals — so much room for speculative conversations!

[Thanks to Consuelo Sendino of The Natural History Museum (London) for correcting the age range of these fascinating organisms.]

References:

Hughes, N.C., Gunderson, G.D. and Weedon, M.J. 2000. Late Cambrian conulariids from Wisconsin and Minnesota. Journal of Paleontology 74: 828-838.

Van Iten, H. 1991. Evolutionary affinities of conulariids, p. 145-155; in Simonetta, A.M. and Conway Morris, S. (eds.). The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press, Cambridge.

Wooster’s Fossil of the Week: Encrusting craniid brachiopods (Upper Ordovician of southeastern Indiana)

May 22nd, 2011

The two irregular patches above are brachiopods known as Petrocrania scabiosa encrusting the ventral valve of yet another brachiopod (Rafinesquina). That species name “scabiosa” is evocative if not a little unpleasant — it is also the root of the English “scab”.

Petrocrania scabiosa is in a group of brachiopods we used to call “inarticulates” because their two valves are not articulated by a hinge as they are in most brachiopods. Instead they are held together by a complex set of muscles. Now we place these brachiopods in the Class Craniforma, an ancient group which originated in the Cambrian and is still alive today.

Petrocrania scabiosa was a filter-feeder like all other brachiopods, extracting nutrients from the seawater with a fleshy lophophore. The Wooster specimens are part of our large set of encrusting fossils (a type of sclerobiont) in our hard substrate collection. They have irregular shells that are circular in outline when they grew alone, and angular when they grew against each other.

Some craniid brachiopods were so thin that their shells repeated the features of the substrate underneath them, a phenomenon known as xenomorphism (“foreign-form”).

Petrocrania scabiosa brachiopods (circular) on a Rafinesquina brachiopod, along with a trepostome bryozoan that encrusted some brachiopods and grew around others. The P. scabiosa on the far left shows xenomorphic features. Specimen borrowed from the University of Cincinnati paleontology collections.

A 2007 College of Wooster paleontology field trip to the Upper Ordovician locality near Richmond, Indiana, where these specimens were found. Students are in the traditional paleontological poses.

Wooster’s Fossil of the Week: A honeycomb coral (Upper Ordovician of southern Indiana)

February 20th, 2011

Polygons are common in nature, whether in two dimensions as desiccation cracks or in three dimensions as with columnar basalt. They result from “closely-packed” disks or tubes. The honeycomb coral (Favosites Lamarck 1816) is one of the best fossil examples of hexagonal packing.

Favosites appeared in the Late Ordovician (about 460 million years ago) and went extinct in the Permian (roughly 273 million years ago). It consists of a series of calcitic tubes (corallites) packed together as closely as possible, thus the resemblance to a honeycomb. The corallites share common walls with each other. They were occupied by individuals known as polyps that were much like today’s modern coral polyps. They had tentacles that extended into the surrounding seawater to collect tiny prey such as larvae and micro-arthropods. (I’m confident here because we actually have fossils showing the soft polyps themselves.)

A, Portion of the corallum of Favosites favosa. B, Portion of four corallites of Favosites gothlandica, enlarged, showing the tabulae and mural pores. (From H.A. Nicholson (1877): "The Ancient Life History of the Earth A Comprehensive Outline of the Principles and Leading Facts of Palæontological Science.")

As you can see in the drawings above, the corallites are distinguished by internal horizontal partitions called tabulae and holes in the walls termed mural pores. These pores most likely allowed internal soft tissue connections between the polyps so that they could share digested nutrients.

Thin-section of Favosites from the Upper Ordovician of southern Indiana. Note the gaps in some corallite walls. These are mural pores.

Favosites as a genus has a very long history. It was named by the famous French natural historian and war hero Jean-Baptiste Lamarck. It is a favorite in paleontology courses because it is so easily recognized.

Wooster Paleontologists in Indiana!

September 12th, 2010

RICHMOND and LIBERTY, INDIANA–The College of Wooster Invertebrate Paleontology class had its field trip today to sunny eastern Indiana. We collected bags and bags of fossils from Upper Ordovician strata for research projects throughout the rest of the course. Each student will be reconstructing a paleocommunity from the fossils, and along the way will learn several paleontological techniques and principles. Our specimens include many strophomenid and orthid brachiopods, trepostome and cyclostome bryozoans, rugose and heliolitid corals, crinoids, nautiloids, a few trilobites, and some mystery fossils I find perplexing. (Always scientific opportunities there!) We hope to show some of our discoveries in later blog posts.

The challenge of this trip was the size of the group: 21 people in five vehicles. It all worked out well for a spectacular field day.

The Invertebrate Paleontology class spreads out along an Upper Ordovician outcrop. Note the great weather.

Travis Louvain and Nick Fedorochuk enjoy a nice exposure.

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