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Wooster’s Fossils of the Week: Geological Magic Lantern Slides from the 19th Century (Part I)

November 25th, 2016

1-teleosaurus-ichthyosaurus-pentacrinites-ammonites-gryphaea“Wooster’s Fossil of the Week” is not always about actual fossils, but our topics are each paleontological. Many years ago I discovered in an old box tucked away in the attic of Scovel Hall at Wooster a set of “Magic Lantern Slides” used in geology courses. I came across them again recently and thought I would share these ancient scenes. Lantern slides were the 19th Century equivalent of PowerPoint, so generations of Wooster geology students must have sat in rapture looking at these colorful images. (At least that’s how I imagine them now viewing my PowerPoint slides!) The above imagined seashore view includes the crocodylian Teleosaurus atop the layered rocks, Ichthyosaurus immediately below, four long-necked Plesiosaurus on the left, an orange cluster of the crinoid Pentacrinus rooted inexplicably in the beach sand, and a scattering of ammonite and oyster shells.  The caption on the image says these animals lived during “the Secondary Epoch of the Earth’s history”. We would now say this is a Jurassic scene. The ichthyosaur looks the most odd to us. Not only is it crawling on the land, it lacks a dorsal fin and the characteristic bi-lobed, shark-like tail. These were later discoveries about ichthyosaurs made only after specimens were found with skin impressions.

2-ammonite-lantern-detailThis close-up shows the detail in these images. Ammonites are on the left (“6”) and the oyster Gryphaea is on the right (“7”).

3a-magic-lantern-slide-geological-585The Magic Lantern Slides are 4×8 inches with the image on glass fixed in a thin slab of wood with metal rings. These are chromolithograph slides, each stamped “T.H. McAllister, Optician, N.Y.”. McAllister was the most prominent of many American producers of lantern slides in the late 19th century.

4-megalosaurus-pterodactyleThe quadrupedal beasts in the foreground are the of the Jurassic theropod dinosaur Megalosaurus, with pterodactyls in the background. We now know Megalosaurus was bipedal, like all theropod dinosaurs.

5-megalosaurus-headAnother detail showing the fine quality of these color images on glass.

6-gigantic-lizards-and-some-pterosauria-by-benjamin-waterhouse-hawkins-1853Most readers with any background in the history of paleontology recognize these reconstructions of ancient life from the work of Benjamin Waterhouse Hawkins (1807-1894). In 1855, Waterhouse Hawkins finished sculpting life-sized models of these extinct animals, along with many others, for the Crystal Palace gardens in London. He was advised for the anatomical details by Sir Richard Owen (1804-1892), a hero of paleontology but not a fan of Darwinian evolution. He is responsible for the dinosaurs of Waterhouse Hawkins looking rather mammalian. Most of these extraordinary animal statues still exist.

9-benjamin_waterhouse_hawkins-_photograph_by_maull__polyblankBenjamin Waterhouse Hawkins (1807-1894). More reconstructions from him, along with his brief biography, in the next installment.


Wooster’s Fossil of the Week: A juvenile conch from the Upper Pleistocene (Eemian) of The Bahamas

November 18th, 2016

inagua-lobatus-gigasI collected this beautiful shell from a seashore exposure of Pleistocene sediments on Great Inagua, the third largest island of The Bahamas. I was on an epic expedition to this bit of paradise with Al Curran and Brian White of Smith College in March 2006. We were pursuing evidence for a sea-level change event in the Eemian, about 125,000 years ago. This was some of the most exciting scientific work I’ve done, so this little shell brings back many memories. I found it loosely cemented into a small patch of carbonate sediments inside a hollow of an ancient coral reef. This shell and numerous other samples were basic data for a rapid rise and fall of sea level during the last interglacial interval. The project is summarized in the Thompson et al. (2011) reference below.

This is a juvenile of the common Queen Conch Lobatus gigas (Linnaeus, 1758). In its adult form with a flared aperture it is one of the most recognizable modern shells in the world. Some of you may be surprised by the generic name. I was. I knew this shell as Strombus gigas, the original name given to it by the sainted father of taxonomy Carolus Linnaeus in 1758. After several adventures in the literature, Landau et al. (2008) placed the species in the genus Lobatus Swainson 1837.

salvador-lobatus-gigas-1The species looks exactly the same today, at least in its shell. This is a similar modern Queen Conch juvenile collected from San Salvador Island in The Bahamas. Note the color patterns which are lost in the fossil.

salvador-lobatus-gigas-2This is the apertural view of the same modern shell. With time it would have grown a much thicker apertural margin to protect it from predators.

buonanni-strombus-gigas-figureThis is the earliest image known of the Queen Conch (Buonanni, 1684). For a long time the type specimen (the specimen of record defining the taxon) of Strombus gigas (the older Linnaeus name) was missing. In 1941 this figure — the figure itself — was designated a neotype (a replacement type) of the species. (First time I’ve heard of that move.) The original type specimen, though, was found in Sweden in 1953, so there is an actual shell in the collections and no need for this neotype.

bonanno-coverThat first figure of Lobatus gigas was drawn by Filippo Bonanni (1638-1723), a remarkable Italian Jesuit scholar. It is found in the book above, which is the first known guide to seashells for collectors. (Note the “SUPERIORUM PERMISSU”, meaning he published with the permission of his Jesuit superiors.) Bonanni was one of the first to suggest fossils had at least some organic origins, speculating that they were either organism remains or “products of natural powers.”


Buonanni, F. 1684. Recreatio mentis, et oculi in observatione animalium testaceorum curiosis naturae inspectoribus italico sermone primum proposita. p. Philippo Bonanno . Nunc denuo ab eodem latine oblata, centum additis testaceorum iconibus, circaquae varia problemata proponuntur. Ex typographia Varesij, Romae, xvi + 270 + [10] pp., 139 pls.

Landau, B.M., Kronenberg G.C. and Herbert, G.S. 2008. A large new species of Lobatus (Gastropoda: Strombidae) from the Neogene of the Dominican Republic, with notes on the genus. The Veliger 50: 31–38.

Thompson, W.G., Curran, H.A., Wilson, M.A. and White, B. 2011. Sea-level oscillations during the Last Interglacial highstand recorded by Bahamas corals. Nature Geoscience 4: 684–687.

White, B.H., Curran, H.A. and Wilson, M.A. 2001. A sea-level lowstand (Devil’s Point Event) recorded in Bahamian reefs: comparison with other Last Interglacial climate proxies; In: Greenstein, B.J. and Carney, C., (editors), Proceedings of the 10th Symposium on the Geology of the Bahamas: Bahamian Field Station, San Salvador Island, p. 109-128.

Wilson, M.A., Curran, H.A. and White, B. 1998. Paleontological evidence of a brief global sea-level event during the last interglacial. Lethaia 31: 241-250.

Wooster’s Fossils of the Week: Modern vermetid snails, a slipper shell, and an oyster

November 11th, 2016

crepidula-vermetidaeNot actually fossils this week, but cool nonetheless. This complex specimen is in our Invertebrate Paleontology teaching collection with no label giving its original location. In the foreground is the underside of a slipper shell gastropod identified as Crepidula fornicata. The tangled mass of tubes encrusting it is a vermetid gastropod. A small round hole drilled by a predatory gastropod is visible in the slipper shell.

vermetidae-oysterTurning the specimen over we see a left valve of the oyster Ostrea encrusting the exterior of the slipper shell, along with another view of the vermetid tubes and gastropod boring.

rafinesque-constantine-1783-1840The twisty gastropod Family Vermetidae was named in 1815 by Constantine Samuel Rafinesque-Schmaltz (1783 – 1840).Rafinesque was a character. His name is immediately recognizable to paleontologists of the Ordovician because Hall and Clarke named the common brachiopod Rafinesquina after him in 1892. Rafinesque was born of a French merchant father (Rafinesque) and German mother (Schmaltz) near Constantinople in the Ottoman Empire. He was self-educated, learning classical languages before his teens and sorting through rocks, minerals, plants, animals and fossils at a prodigious rate. He began to write numerous articles and books on anthropology, botany, zoology, geology, paleontology, history, and linguistics. The naturalist and philosophical establishment rejected him, for the most part, so he was little praised in his life. Most scholars agree now that he was ahead of his time on many topics, including evolution.

In 1819, Rafinesque was appointed professor of Botany at Transylvania University in Lexington, Kentucky. He apparently attracted considerable trouble during his years in Kentucky. In 1826 he was either fired by the university president or he walked out in a huff. Legend is that he left an angry curse on the school! He died in Philadelphia in 1840 of stomach cancer, to which some attributed to his own homemade medications.

screen-shot-2016-11-07-at-9-49-57-amThe cover page of Rafinesque’s 1815 work in which he attempted to classify just about everything in the universe. Note the subheading: “Nature is my guide, and Linnaeus is my master.”

screen-shot-2016-11-07-at-9-49-32-amA suitably grand frontispiece for the 1815 book.

screen-shot-2016-11-07-at-10-37-25-amThis is the extent of establishing a new family in the early 19th century (Rafinesque, 1815, p. 144). No wonder Rafinesque could name, by his own count, over 6700 taxa.


Hall, J. and Clarke, J.M. 1892. An introduction to the study of the genera of Palaeozoic Brachiopoda. Part I. Geological Survey of the State of New York, Paleontology 8, p. 1-367.

Rafinesque, C.S. 1815. Analyse de la nature: ou tableau de l’univers et des corps organisés. J. Barravecchia: Palermo. 224 pages.

How thick was the ice?

November 8th, 2016

AMHERST, MA – Our Keck project studying the construction of a glaciovolcanic ridge in southwest Iceland is in full swing and our students are hard at work on their research. You may remember that we traveled to Iceland this summer to conduct field work, then returned to Wooster, where we prepared our samples for analysis. All of the time and energy devoted to sample preparation is finally paying off. This weekend, Chloe Wallace (’17, Wooster) and I met Cara Lembo (’17, Amherst) at UMass Amherst to analyze their samples by Fourier Transform Infrared Spectroscopy (FTIR) and Electron Microprobe.

Chloe and Cara are trying to determine the emplacement pressure of the samples. The emplacement pressure should reveal information about water depth (or ice thickness) at the time of the eruption. To estimate emplacement pressure, they are using the volatile contents of the quenched glass rims of pillow lavas. Volatiles are lost during an eruption as a function of pressure; the smaller the pressure, the more degassing. So, by measuring the volatiles that are trapped in the glass, we can figure out how much pressure the glass experienced when it was formed.

Prior to the visit, Chloe and Cara selected the freshest glass chips, then polished them into ~100-200 micron-thick wafers. They analyzed them for H2O using the FTIR, making sure to avoid any vesicles, crystals, and fractures. They collected nearly 300 data points on 16 samples, so they have a thorough and extensive dataset to work with.

Chloe (left) is looking for an ideal measurement location on her glass chip. Cara (right) is operating the data collection and reduction software.

Chloe (left) is looking for an ideal measurement location on her glass chip. Cara (right) is operating the data collection and reduction software.

In order to calculate water depth (or ice thickness) from H2O concentration, we use a solubility model. The model requires additional inputs, including the glass composition, which we measured by electron microprobe.

After the glass chips were analyzed by FTIR, they were mounted on a glass slide for probe analysis.

After the glass chips were analyzed by FTIR, they were mounted on a glass slide for probe analysis.

The electron microprobe allows us to measure the composition of a very small (micron-scale) spot on the glass chip.

Chloe is examining her glass chips on the microprobe.

Chloe is examining her glass chips on the microprobe.

Cara uses the map to find her way around the slide. They analyzed several points on each chip, and will use those data to determine the glass composition.

Cara uses the map to find her way around the slide. They analyzed several points on each chip, and will use those data to determine the glass composition.

It was a short and intense visit, but we accomplished all of our goals. We especially would like to recognize Dr. Sheila Seaman for generously giving her time and energy. She made it all possible.

Wooster’s Fossils of the Week: Demosponge borings in a muricid gastropod from Florida

November 4th, 2016

entobia-snail-2Technically these are “subfossils” since this appears to be an old shell still within the Holocene, although it is possibly eroded out of Pleistocene sediments and then redeposited on a Florida beach. It is a muricid snail eroded enough to erase any specific characters for further identification. It is cool because it is thoroughly bored by clionaid demosponges, producing a beautiful pattern of holes given the ichnological name Entobia Bronn 1838.

entobia-snail-1On the left side of the aperture of this snail shell is a fine reticulate pattern from an encrusting cheilostome bryozoan, also punctured by Entobia. That bryozoan is in a favored place for filter-feeding encrusters on snail shells, so it likely was there during the life of the snail.

As a trace fossil this structure would be known as Entobia. It is very common in the fossil record, especially in the Cretaceous and later.

Bronn 041616Entobia is common in the fossil record, especially in calcareous rocks and fossils from the Cretaceous on. The ichnotaxon was named (but apparently not described) in 1838 by Heinrich Georg Bronn (1800-1862), a German geologist and paleontologist we’ve met before in this blog. He had a doctoral degree from the University of Heidelberg, where he then taught as a professor of natural history until his death. He was a visionary scientist who had some interesting pre-Darwinian ideas about life’s history. He didn’t fully accept “Darwinism” at the end of his life, but he made the first translation of On The Origin of Species into German.


Bromley, R.G. 1970. Borings as trace fossils and Entobia cretacea Portlock, as an example. Geological Journal, Special Issue 3: 49–90.

Bronn, H.G. 1838. Lethaea geognostica: oder, Abbildungen und Beschreibung der für die Gebirgs-Formationen bezeichnendsten. E. Schweizerbart’s Verlagshandlung, Stuttgart, 545 pages.

Buatois, L., Wisshak, M., Wilson, M.A. and Mángano, G. 2016. Categories of architectural designs in trace fossils: A measure of ichnodisparity. Earth-Science Reviews (DOI: 10.1016/j.earscirev.2016.08.009).

Taylor, P.D. and Wilson, M.A. 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62: 1-103.

Wilson, M.A. 2007. Macroborings and the evolution of bioerosion, p. 356-367. In: Miller, W. III (ed.), Trace Fossils: Concepts, Problems, Prospects. Elsevier, Amsterdam, 611 pages.


Wooster’s Fossil of the Week: A naticid gastropod from the Pliocene of southern California

October 28th, 2016

polinices-galianor-sd-pliocene-1-copyThis week’s fossil comes from our teaching collection. It’s label appears to be from the late 19th Century. It is a naticid gastropod (“moon snail“) listed as Polinices galianor. That name, which I can only find in two lists and never with an author, may be a corruption of Polinices (Euspira) galianoi Dall 1909. It was collected from the Pliocene of San Diego County, California. It is preserved as both an internal mold and thin sheets of remnant original shell.

polinices-galianor-sd-pliocene-2-copyThis is a view of the underside along the axis of coiling. The hole is known as the umbilicus and is distinctive for the naticids. These snails are predatory, moving through loose sand with a very large foot and capturing shelled prey, like clams and other gastropods. They then drill a beveled hold through the shell of the prey with specialized teeth in their radulae. We’ve discussed the trace fossils they leave (Oichnus) in a previous post.

The genus Polinices was named in 1810 by Pierre Dénys de Montfort (1766–1820), a French malacologist (one who studies mollusks).

screen-shot-2016-10-22-at-11-52-46-amThe title page of de Monfort (1810).

screen-shot-2016-10-22-at-11-49-26-amThis brief paragraph is all it took in the early 19th Century to name a new taxon. The system is much more elaborate now.screen-shot-2016-10-22-at-8-20-44-pmPierre Dénys de Montfort is a tragic figure in science. First, he had the misfortune of being a French intellectual during the chaos of the French Revolution and the resulting Napoleonic dictatorship. Scientists struggled then, but after service in the revolutionary army and an apprenticeship with a geologist, de Monfort gained a position in the Jardin des Plantes, a research botanical garden in Paris. He did a massive study of mollusks, producing systematic tomes. De Monfort was a whiz at languages, so he did well as a translator after Napoleon was  finally defeated in 1815 and the Allied armies occupied Paris. Then he went off the rails. He had since 1801 championed the reports of mariners that giant cephalopods occasionally rose from the sea and attacked shipping, as shown in his above print (de Monfort, 1801, p. 256). The modern roots of the kraken! De Monfort took the idea too far, was ridiculed in the scientific community, and eventually died of starvation and alcoholism in the streets of Paris in 1820. The later discovery of giant squid salvaged his reputation a bit, but no one has yet found evidence of “le poulpe colossal”.


Dall, W.H. 1909. Contributions to the Tertiary paleontology of the Pacific coast. U.S. Geological Survey Professional Paper 59. U.S. Government Printing Office, 288 pages.

de Montfort, P.D. 1801. Histoire naturelle, générale et particuliere des Mollusques, animaux sans vertèbres et á sang blanc. Volume 2. Paris, 424 pages.

de Montfort, P.D. 1810. Conchyliologie systématique, et classification méthodique de coquilles. Volume 2. Paris, 692 pages.


Wooster’s Pseudofossils of the Week: Artifacts in thin-sections of Ordovician limestones from southeastern Minnesota

October 21st, 2016

1bubfirstIt is always exciting to a geologist when thin-sections of curious rocks are completed and ready for view. A thin-section is a wafer of rock (30 microns thick) glues to a glass slide and examined by transmitted light through a petrographic microscope. They provide fantastic views of the mineralogy, paleontology, and structure of a rock in exquisite detail. Thin-sections are also full of mysteries since we have essentially two-dimensional slices through three-dimensional materials.

Thin-sections from the Decorah Formation samples collecting by Team Minnesota this past summer were finally available this week for study. I took the first look at slides of limestones containing ferruginous (iron-rich) ooids we gathered as part of Etienne Fang’s (’17) Independent Study. The first structures I saw were the crazy dark outlines above. What sort of fossils are these, I wondered. Could they be sponges? Odd bryozoans? Borings through the rock fabric? I was ready to post them here as mystery fossils to solicit your opinions. Now, though, they instead make a cautionary tale.

2bub730There are many of these features in a single slide from the Decorah Formation exposed at the Golden Hill outcrop near Rochester, Minnesota. Some are astonishingly complex. It then began to occur to me that these structures were too convoluted and unpredictable to actually be fossils. It also bothered me that to focus on them required to put the rest of the field out of focus. That only made sense if these oddities were in the epoxy, not the rock itself.

3buboverlapEtienne showed me how to demonstrate that these funny loops were not in the rock with this view: You can just make out the greenish lines overlapping the cut surface of this ferruginous ooid. Turns out I was excited about air bubbles in the cementing epoxy. They have nothing to do with the rock. I nearly posted my own pseudofossils.

4trio7321I held out hope, though, that these odd white objects in another thin-section of ooid-rich limestone. They appear to be ghostly outlines of ooids with a finely-textured object inside. They look like seeds with embryos within. Several are scattered through the thin-section. Another mystery fossil!

5duo7321A closer view. Strange how each internal object seems connected to an ooid on the outside, making them asymmetrical in their placements.

6single7321Strange also how once again the details of the internal object can only be seen with the rest of the slide out of focus. Yes, another artifact in the epoxy. This time we may be looking at holes left by ferruginous ooids plucked from the rock through the grinding process, pulling a patch of epoxy with them. Somehow this happened when the now-missing ooid was wedged against another. Nothing to see here, folks.

7ooid7301fAt least I can take the opportunity to show how cool Etienne’s ferruginous ooids are. Note that this one has a greenish layer midway through the cortex. It looks like the mineral chamosite to me. Spectacular detail in the lamellae, but only visible if the image is over-exposed.

8bifoliate7301hThere are plenty of real fossils in these thin-sections, of course. My favorites are these bifoliate bryozoans (lower right half) with their zooecia filled with ferruginous material. Note that the ooid above has had some of its lamellae dissolved away, probably because of some mineral diversity. Also note in the upper right another one of those crazy air bubbles.

The lesson I learn over and over: think, but then think again.




Wooster’s Fossil of the Week: Spiriferinid brachiopod from the Lower Carboniferous of Ohio

October 14th, 2016

syringothyris-texta-hall-1857-anterior-585Sometimes I choose a Fossil of the Week from our Invertebrate Paleontology teaching collection because students have responded to it in some way. This week’s fossil brachiopod has confused my students a bit because it is an internal mold (unusual for brachiopods in our experience) and a member of the Order Spiriferinida rather than the Order Spiriferida. (Catch that? The difference is in two letters.) It is Syringothyris texta (Hall 1857) from a local exposure of the Logan Formation (Lower Carboniferous). Above is a view of the anterior showing the medial fold and sulcus (like an anticline). This, by the way, is the largest brachiopod in our collection.

syringothyris-texta-hall-1857-posterior-585Syringothyris Winchell, 1863, is a genus within the order Spiriferinida, as noted before. This order was erected in 1994, pulling it from the more familiar Order Spiriferida. In this preservation, the spiriferinids are distinguished by a high cardinal area in the posterior (shown above). Not much higher than the spiriferids, truth be told.

syringothyris-texta-hall-1857-dorsal-585This is a view of the dorsal valve side of this internal mold. Note the absence of ribs (plicae) on the fold in the middle.

a_winchellThe geologist and paleontologist Alexander Winchell (1824-1891) named and described the genus Syringothyris. We met Winchell before in this blog as he described many common fossil taxa in the Midwest. He was born in upstate New York, a seventh-generation New Englander. In 1847 he was graduated from Wesleyan University in Connecticut. He had a varied and peripatetic career, spending most of his time as a teacher of science. He first taught in New Jersey, New York and Alabama, staying a short time in each place. He founded the Mesopotamia Female Seminary in Eutaw, Alabama, and became president (briefly) of Masonic University in Selma. In 1854, Winchell was appointed professor of physics and civil engineering at the University of Michigan, a position that soon became geology and paleontology. Five years later he became the state geologist of Michigan, a job characterized by an apparently difficult relationship with his superiors. In 1872 he left Michigan to be chancellor of Syracuse University, lasting only two years. Next he was a professor of geology and zoology at Vanderbilt University, a position he was forced to resign from in 1878 due to his unbiblical views of evolution. Winchell then returned to the University of Michigan, again as a professor of geology and paleontology. There is where he died.

Winchell’s views on evolution were complicated by his religiosity, and his religious life was made difficult by evolution. He developed a kind of transcendental Darwinism in which selection was reduced to inflexible laws from the Creator, a view we would today call Intelligent Design. He then confused it all by writing a popular book called Preadamites, published in 1880. The darker races, he said, lived in Europe and Asia before Adam. Adam and the subsequent “Noachites” were derived from Negroes, according to Winchell, advancing steadily in intellectual development and whiteness while the black race and other Preadamites were left behind. This work is profoundly racist and pseudoscientific, despite the Darwinian gloss he attempted to paint over it.

a-screen-shot-2016-10-10-at-8-49-42-pmb-screen-shot-2016-10-10-at-8-57-04-pmFrontispiece of Winchell (1880).


Bork, K.B. and Malcuit, R.J. 1979. Paleoenvironments of the Cuyahoga and Logan Formations (Mississippian) of central Ohio. Geological Society of America Bulletin 90: 89–113.

Vörös, A., Kocsis, Á.T. and Pálfy, J. 2016. Demise of the last two spire-bearing brachiopod orders (Spiriferinida and Athyridida) at the Toarcian (Early Jurassic) extinction event. Palaeogeography, Palaeoclimatology, Palaeoecology 457: 233-241.

Winchell, A. 1863. Descriptions of FOSSILS from the Yellow Sandstones lying beneath the “Burlington Limestone,” at Burlington, Iowa. Academy of Natural Sciences of Philadelphia, Proceedings, Ser. 2, vol. 7: 2-25.

Winchell, A. 1880. Preadamites; or a demonstration of the existence of men before Adam. Chicago, S.C. Griggs and Company; 500 p.

Wooster’s Fossils of the Week: Upper Ordovician strophomenid brachiopods from Iowa

October 7th, 2016

leptaena-585Since we are covering brachiopods in my paleontology course this week, I’ve chosen a very recognizable genus from the Upper Ordovician of Iowa for our Fossil of the Week. This wrinkly strophomenid brachiopod is of the genus Leptaena Dalman, 1828. It is one of the most common brachiopods in the Lower Paleozoic, ranging from the Ordovician into the Carboniferous. The two specimens above are showing their dorsal valve exteriors.

leptaena-dorsal-585The same specimens are here turned over, showing the ventral valve exterior on the left and the dorsal valve interior on the right.

I always learn something when writing these brief fossil posts. These specimens are labeled in our collections as Leptaena rhomboidalis (Wahlenberg, 1818), the most common species name I’ve seen for this genus. Hoel (2005, p. 266), however, says: “In fact, L. rhomboidalis is known only from Gotland, [Sweden,] where it was confined to moderate energy reef environments during the early Wenlockian [Silurian].” So this species is only Silurian, and only found on a Swedish island. I’ll just leave it in open nomenclature, then, as Leptaena sp. The taxonomic details of the many species in the genus are beyond my skills and experience.
gwahlenbergThe erroneous species name, though, does introduce us to a fascinating Swedish naturalist named Göran Wahlenberg (1780-1851). This man is best known as a botanist, but he also had many geological and paleontological interests. He entered Uppsala University in 1792, earning a doctorate in medicine in 1806, and then joining the faculty to teach botany and medicine (with much more emphasis on the first). He occupied the university chair previously held by the demigod taxonomist Carl Linnaeus. He was elected at a young age to the Royal Swedish Academy in 1808. Wahlenberg’s primary work was with plant biogeography, especially in Sweden, but he made many scientific forays throughout Scandinavia and into Central Europe. He named Anomites rhomboidalis in 1818, which was later added to the genus Leptaena.

Wahlenberg studied glaciers in Scandinavia, making many observations about glacial striations and moraines we would recognize today. His main overarching theory of Earth history was that massive vulcanism in the “pre-Adamite” past caused great climate changes, eventually producing a global flood, the evidence for which included glacial erratics strewn throughout northern Europe. He was one of the first naturalists to posit connections between atmospheric composition and global temperatures.

What the scientific biographies of Göran Wahlenberg don’t often mention is that he is credited as the first person to bring the pseudoscience of homeopathy to Sweden. He studied the medicinal ideas of the founder of homeopathy, Samuel Hahnemann, and declared they had merit. He was an enthusiastic advocate, making him one of the “pioneers of homeopathy”. In his defense, at that time homeopathy was no doubt safer than mainline medicine!


Hoel, O.A. 2005. Silurian Leptaeninae (Brachiopoda) from Gotland, Sweden. Paläontologische Zeitschrift 79: 263-284.

Kelly, F.B. 1967. Silurian leptaenids (Brachiopoda). Palaeontology 10: 590-602.

Wahlenberg, G., 1818. Geologisk avhandling om svenska jordens bildning. Uppsala.

Wooster’s Pseudofossil of the Week: It’s not what it looks like

September 30th, 2016

Pseudocoprolite 585Impressive, isn’t it? You can practically smell it steaming on your screen. Hard to believe this object is Miocene in age, about 6 million years old.
Pseudocoprolite top view 585Here’s another similar specimen in a top view, if we can say that.
Pseudocoprolite side view 585And here’s a side view. Notice the rich color, long, parallel striations, and “pinched” ends. If these aren’t fossil feces, officially known as coprolites, they’re excellent imitations. They’ve been prime attractions in our first paleontology lab.

These evocative objects are primarily made of siderite, making them dark and heavy. Our specimens above come from the Wilkes Formation (upper Miocene) in southwestern Washington state. They are enormously abundant and thus common in rock shops and museums around the world. In that is your first clue: how can feces with such exquisite detail be preserved so perfectly in such enormous numbers in so few places? My answer, along with many other geologists, is that these are pseudocoprolites made by inorganic means. Their extrusive nature and appropriate color gives us the illusion of poop.

I’m highlighting these objects this week because a paper appeared last month in the journal Lethaia making a case that they actually are biological in origin. Broughton (2016), in a long bit of prose and analysis, concludes that the Wilkes Formation objects are a mix of giant earthworm “mineralized intestinal remains (Type 2)” and coprolites “from unknown vertebrates” (Type 1). I don’t buy Broughton’s interpretations, but found them fascinating enough to make his paper part of a reading exercise in my paleontology class this month. The most relevant references are below so you can do your own reading and decide what these curious extrusions (or intestinal casts) are.

Let’s start with this excellent 2014 article by Brian Switek for National Geographic: “Was Six-Million-Year-Old Turd Auctioned for $10,000 a Faux Poo?” Yes, one of these curiosities actually sold for $10,370 at an auction … and it is over 100 centimeters long! (Check out the images in this NPR article on the auction. That would be an epic poop for anyone.) This auctioned specimen is an example of what Broughton (2016) calls Type 2; he believes they are essentially mineralized guts of really large burrowing earthworms. He makes his case by interpreting the striations as muscle fiber impressions, and the shapes as resulting from peristaltic motions inside the worms. (Seilacher et al., 2001, had similar ideas.) The smaller “faecal-like specimens”, like we have at Wooster, are his “Type 1”. As far as I can tell, only length separates Type 1 from Type 2 in Broughton’s classification and, as might be expected, “Some fragmentary Type 2 specimens may be misidentified as Type 1.” It is odd that Types 1 and 2 are identical in every feature but size, yet are given very different origin stories.

Critical observations to keep in mind as you explore this mystery: (1) These siderite objects have no inclusions of organic material — not a seed, woody bit, or bone fragment; (2) There are no associated vertebrate skeletal remains or other traces, and no evidence for earthworms either; (3) They are incredibly abundant in limited horizons, and unknown elsewhere; (4) They range in size from a centimeter or less to over 100 centimeters long; (5) You’d think you’d find a few squashed, now and then, or burrowed by insects, but they are in spectacular three-dimensional preservation.

I support the earlier interpretations of these excrement-appearing rocks as deformations of soft, plastic sediments by inorganic processes, as thoroughly developed by Spencer (1993), Mustoe (2001) and Yancey et al. (2013). They may have been extruded through rotting hollow logs by compaction, liquified by seismic activity, or squirted through cracks by natural gas emissions (which would be ironic!). That these pseudocoprolites were squeezed through something seems obvious; it is unlikely they came to us by way of animals.


Broughton, P.L. 2016. Enigmatic origin of massive Late Cretaceous‐to‐Neogene coprolite‐like deposits in North America: a novel palaeobiological alternative to inorganic morphogenesis. Lethaia (early view)

Mustoe, G.E. 2001. Enigmatic origin of ferruginous “coprolites”: Evidence from the Miocene Wilkes Formation, southwestern Washington. Geological Society of America Bulletin 113: 673-681.

Seilacher, A., Marshall, A., Skinner, C. and Tsuihiji, T. 2001. A fresh look at sideritic ‘coprolites’. Paleobiology 27: 7–13.

Spencer, P.K. 1993. The ‘coprolites’ that aren’t: the straight poop on specimens from the Miocene of southwestern Washington State. Ichnos 2: 231–236.

Yancey, T.E., Mustoe, G.E., Leopold, E.B. and Heizler, M.T. 2013. Mudflow disturbances in latest Miocene forests in Lewis County, Washington. Palaios 28: 343–358.

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