Wooster Geologists

Mark Wilson May 12th, 2013

At first specimen this looks like a series of holes drilled into a small, smooth substrate (like Trypanites), but then you notice that the substrate has grown up around the holes, and on the far left you can make out two cones. These are cornulitid tubes that lived on and then inside a living stromatoporoid sponge. Jonah Novek (’13), a Wooster geologist graduating tomorrow, found these in the Hilliste Formation (Rhuddanian, Llandovery) during his Independent Study work on Hiiumaa Island in Estonia.

My Estonian paleontologist friend Olev Vinn is the expert in bioclaustrated (embedded in a living substrate) cornulitids, as you can see from the papers listed below. These fossils are an excellent example of endosymbiosis, or the living relationship of one organism embedded within the skeleton of another (see Tapanila and Holmer, 2006). We can’t tell yet without a thin-section, but the cornulitid here is probably very similar to the Sheinwoodian (Wenlock) Cornulites stromatoporoides Vinn and Wilson, 2010. The specimen shown above is already in the mail to Estonia for further analysis. This specimen is the earliest example of cornulitid endosymbiosis in the Silurian.
A closer view of the embedded cornulitid tubes. The tubes in these holes appear to have dissolved away, at least in their distal parts. Some of the details of the stromatoporoid substrate are just visible.

Fond memories of the 2012 Wooster-Ohio State University expedition to Estonia. Jonah Novek (’13), me, and Richa Ekka (’13) on the top of the Kõpu Lighthouse, Hiiumaa Island, Estonia. Photo by our friend Bill Ausich (OSU).

Congratulations to Jonah on his find, and best wishes to all the senior Wooster Geologists on this graduation weekend.

References:

Tapanila, L. and Holmer, L.E. 2006. Endosymbiosis in Ordovician-Silurian corals and stromatoporoids: A new lingulid and its trace from eastern Canada. Journal of Paleontology 80: 750-759.

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.

Vinn, O. and Wilson, M.A. 2012a. Encrustation and bioerosion on late Sheinwoodian (Wenlock, Silurian) stromatoporoids from Saaremaa, Estonia. Carnets de Géologie [Notebooks on Geology], Brest, Article 2012/07 (CG2012_A07).

Vinn, O. and Wilson, M.A. 2012b. Epi- and endobionts on the Late Silurian (early Pridoli) stromatoporoids from Saaremaa Island, Estonia. Annales Societatis Geologorum Poloniae 82: 195-200.

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Mark Wilson May 5th, 2013

This weathered trilobite is nothing like the gorgeous specimens of this genus you can buy at various rock shops around the world and on the web, but it has sentimental value to me. I collected it on an epic field trip in Russia in 2009. We hacked our way through the woods to an exposure of the Frizy Limestone (Volkhov Regional Stage, Darriwilian Stage, Middle Ordovician) where the local people had a side industry of quarrying out these trilobites for international trade. This specimen was the best I found, and it was probably abandoned by other collectors as too damaged. Still, it makes a nice reminder of my Russian experience and I keep it on a cabinet in my office. (By the way, I did not make a Cold War mistake in referring to the “Leningrad Region“. This oblast retains the old name of the city now known as St. Petersburg. Apparently the residents voted to keep it that way after the Soviet Union collapsed.)
This is the asaphid trilobite Asaphus lepidurus Nieszkowski, 1859. This group is known for having fantastic eyes, some on long stalks and others with calcareous “eyeshades” above them. This species has more conventional eyes, but they’re still cool.
A. lepidurus studies us with a cold, dead eye. From this perspective the facial suture is visible as the curved, raised line running from the near eye to the periphery of the cephalon (head). This is a line of weakness the trilobite used to split its exoskeleton for molting (ecdysis). These sutures often have diagnostic value for distinguishing trilobites, especially at the species level.

A. lepidurus was first described and named by Jan Nieszkowski (1833-1866), a Polish paleontologist (and naturalist and medical doctor). He was born in Lublin, Poland, son of an army captain. He studied at the University of Dorpat (now the University of Tartu in Estonia) and soon became an avid and productive paleontologist. He then participated in the January Uprising of Poles against the occupying Russians in 1863. He was captured and exiled to the Russian city of Orenburg, where he died at a young age of typhus.

This little trilobite brings back memories of my Russian adventure, and it is also a reminder that science is never done in a political vacuum. Here’s to the Polish patriot and scientist Dr. Jan Nieszkowski.

References:

Dronov, A., Tolmacheva, T., Raevskaya, E., and Nestell, M. 2005. Cambrian and Ordovician of St. Petersburg region. 6th Baltic Stratigraphical Conference, IGCP 503 Meeting; St. Petersburg, Russia: St. Petersburg State University.

Ivantsov, A.Y. 2003. Ordovician trilobites of the Subfamily Asaphinae of the Ladoga Glint. Paleontological Journal 37, supplement 3: S229-S337.

Nieszkowski, J. 1859. Zusätze zur Monographie der Trilobiten der Ostseeprovinzen, nebst der Beschreibung einiger neuen obersilurischen Crustaceen. Archiv für die Naturkunde Liv-, Ehst-, und Kurland, Serie 1: 345-384.

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Mark Wilson April 28th, 2013

This is one of the simplest fossils ever: a cylindrical hole drilled into a hard substrate like a skeleton or rock. The above image is of a hardground (cemented carbonate seafloor) from the Upper Ordovician of northern Kentucky with these borings cut perpendicularly to the bedding and descending downwards. Each boring is filled with light-colored dolomite crystals. This boring type is given the trace fossil name Trypanites weisi Magdefrau 1932.
Trypanites, shown above cutting into a trepostome bryozoan from the Upper Ordovician of southeastern Indiana, is a very long-ranging trace fossil. It first appears in the Lower Cambrian and it is still formed today — a range of 540 million years (James et al., 1977; Taylor and Wilson, 2003). It was (and is) made by a variety of worm-like organisms, almost always in carbonate substrates. Today the most common producers of Trypanites are sabellarid polychaete and sipunculid worms. Trypanites was the most common boring until the Jurassic, when it was overtaken in abundance by bivalve and sponge borings. Trypanites was the primary boring in the Ordovician Bioerosion Revolution (Wilson and Palmer, 2006).
Trypanites is defined as a cylindrical, unbranched boring in a hard substrate (such as a rock or shell) with a length up to 50 times its width (Bromley, 1972). The typical Trypanites is only a few millimeters long, but some are known to be up to 12 centimeters in length (Cole and Palmer, 1999). The above occurrence of Trypanites is one of my favorites. The organisms bored into a bryozoan colony (the fossil in the upper left and center with tiny holes) and down into a bivalve shell the bryozoan had encrusted. The borer then turned 90° and drilled horizontally through the aragonitic and calcitic layers of the shell. The aragonite dissolved, revealing the half-borings of Trypanites.
In this bedding plane view, Trypanites weisi borings are shown cutting into a hardground from the Liberty Formation (Upper Ordovician) of southeastern Indiana. This is a significant occurrence because the borings are cutting through brachiopod shells cemented into the hardground surface. When the brachiopods are dislodged from the hardground, those with holes in them erroneously appear to have been bored by predators (see Wilson and Palmer, 2001).

The simplest of fossils turns out to have its own levels of complexity!

References:

Bromley, R.G. 1972. On some ichnotaxa in hard substrates, with a redefinition of Trypanites Mägdefrau. Paläontologische Zeitschrift 46: 93–98.

Cole, A.R. and Palmer, T.J. 1999. Middle Jurassic worm borings, and a new giant ichnospecies of Trypanites from the Bajocian/Dinantian unconformity, southern England. Proceedings of the Geologists’ Association 10 (3): 203–209.

James, N.P., Kobluk, D.R. and Pemberton, S.G. 1977. The oldest macroborers: Lower Cambrian of Labrador. Science 197 (4307): 980–983.

Taylor, P.D. and Wilson. M.A. 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62 (1-2): 1–103.

Wilson, M.A. and Palmer, T.J. 2001. Domiciles, not predatory borings: a simpler explanation of the holes in Ordovician shells analyzed by Kaplan and Baumiller, 2000. Palaios 16: 524-525.

Wilson, M.A. and Palmer, T.J. 2006. Patterns and processes in the Ordovician Bioerosion Revolution. Ichnos 13: 109–112.

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Mark Wilson April 21st, 2013

Another brachiopod this week. This simple fossil is an internal mold of the brachiopod Pentamerus oblongus (J. de C. Sowerby, 1839). It was a very common and widespread taxon throughout North America and Europe in the Early Silurian. This particular specimen was found in a dolomite of the Clinton Group of New York State. This species has been an important fossil for reconstructing Early Silurian paleocommunities, and it is useful in biostratigraphy as well.

I chose this specimen because it has the preservation I have seen in almost every pentamerid brachiopod I have collected: it is an internal mold formed when sediment filled the calcitic shell, was cemented, and then the shell dissolved. We are looking at an impression of a sort of the interior surface of the brachiopod. The posterior (hinge region) of the brachiopod is at the top of this view. You can see a straight slit that represents the ventral muscle field complex (spondylium) that was part of the ventral valve. This was a kind of shelly septum on the floor of the brachiopod interior. we would not see this feature (or rather what is left of it) if the exterior shell had not been removed.
The above is a drawing of Pentamerus oblongus as it looked with its original shell. In this view, unlike our specimen, we are looking at the dorsal valve with the ventral valve visible beneath it.
The genus Pentamerus was named in 1813 by James Sowerby (1757-1822), a prolific scientist we met earlier with our specimen of the Cretaceous bivalve Inoceramus. The species Pentamerus oblongus was fittingly named by his eldest son, James de Carle Sowerby (1787-1871), in 1839. J. de C. Sowerby is shown above in his latter years. The younger Sowerby was an unusual combination of a paleontologist, botanist and mineralogist. He was a friend of the extraordinary scientist Michael Faraday (1791-1867), so he would have had encouragement to be an accomplished polymath. He is said to have conceived one of the first classification of minerals by their chemical compositions. In 1838, J. de C. Sowerby and his cousin Philip Barnes founded the Royal Botanic Society and Gardens (now part of Regent’s Park, London). On top of all this, he was a spectacular scientific illustrator. How many such diverse scientists do we have today?

References:

Johnson. M.E. 1977. Succession and replacement in the development of Silurian brachiopod populations. Lethaia 10: 83-93.

Johnson, M.E. and Colville, V.R. 1982. Regional integration of evidence for evolution in the Silurian Pentamerus-Pentameroides lineage. Lethaia 15: 41-54.

Ziegler, A.M., Cocks, L.R.M. and Bambach, R.K. 1968. The composition and structure of Lower Silurian marine communities. Lethaia 1: 1-27.

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Mark Wilson April 14th, 2013

Sure, I could have picked a pristine shell from our collection, but I like the rugged character of this one. It is the terebratulid brachiopod Coenothyris oweni Feldman, 2002, from the lower Saharonim Formation (Middle Triassic) of Har Devanim, southern Israel. I picked it up, along with a dozen others, during our 2010 Israel expedition.

Above we have a dorsal view of this brachiopod. The posterior is at the top, anterior at the bottom. The round hole is the pedicle opening in the ventral valve. (The pedicle is a fleshy stalk the brachiopod uses to attach to a substrate.) As with all brachiopods, you can see the bilateral symmetry of the shell with the plane perpendicular to the hinge between the valves. Terebratulids are still around.

The layered units at the top of this ridge of Har Devanim are the lower part of the Saharonim Formation (Anisian, Middle Triassic). Micah Risacher (’11) is just visible.

Coenothyris oweni was named in 2002 by my friend Howie Feldman. He also wrote a 2005 paper on the paleoecology of this species in the Saharonim Formation of southern Israel. The brachiopods are sometimes found in obrution deposits, meaning they were buried alive by storm-driven sediments (see above).

The genus Coenothyris was named by Joseph Henri Ferdinand Douvillé in 1879 (above as a young man and older). He was a French paleontologist and geologist who worked first as a mining engineer and then a professor of paleontology at the École des Mines (School of Mines). His research took him around the world, but his most prominent papers were on French fossils and geology. In 1881 he became president of the Société géologique de France; in 1907 he was elevated to the Académie des Sciences.

References:

Feldman, H.R. 2002. A new species of Coenothyris (Brachiopoda) from the Triassic (Upper Anisian-Ladinian) of Israel. Journal of Paleontology 76: 34-42.

Feldman, H.R. 2005. Paleoecology, taphonomy, and biogeography of a Coenothyris community (Brachiopoda, Terebratulida) from the Triassic (Upper Anisian-Lower Ladinian) of Israel. American Museum Novitates, no. 3479: 1-19.

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Mark Wilson April 7th, 2013

Visitors often bring rocks and fossils to the Geology Department for identification. We love to solve the puzzles (or at least make the attempt), and our new friends appreciate names and ages for their treasures. (Usually. We’ve disappointed more than a few finders of “meteorites”.) Last week a home-schooling group came in from nearby Ashland with a tray of stones they found in a stream bed eroding an exposure of the Lower Carboniferous (Kinderhookian) Meadville Shale Member of the Cuyahoga Formation. One of the objects was the spectacular fossil shown above.

This is a calyx and the attached arms (essentially the “head”) of a camerate crinoid known as Cusacrinus daphne (Hall, 1863). (Our friend Bill Ausich of Ohio State University provided the identification — these crinoids are his speciality.) It is preserved as an external mold, meaning that the actual skeleton was covered in sediment (or in this case a concretion) and then dissolved away, leaving a cavity showing a mold of its exterior details. It is a rare fossil to find in our part of the world.

Above is a close-up of the calyx of Cusacrinus daphne (Hall, 1863). Note the radiating ridges on the exteriors of each thecal plate. They are characteristic of this species.

These are some of the arms of the crinoid. They are complex because each arm is lined with tiny branches called pinnules, making feather-like extensions for filter-feeding.

Thank you to our new Ashland friends for sharing such a beauty with us!

References:

Ausich, W.I. and Roeser, E.W. 2012. Camerate and disparid crinoids from the Late Kinderhookian Meadville Shale, Cuyahoga Formation of Ohio. Journal of Paleontology 86: 488-507.

Kammer, T.W. and Roeser, E.W. 2012. Cladid crinoids from the Late Kinderhookian Meadville Shale, Cuyahoga Formation of Ohio. Journal of Paleontology 86: 470-487.

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Mark Wilson March 31st, 2013

Most people have seen this fossil fish type. Geologists, in fact, have probably seen Knightia eocaena Jordan, 1907, thousands of times. It is present in nearly every gift shop that sells fossils, usually as small plaques or glued to refrigerator magnets. It is the state fossil of Wyoming and, by all accounts, the most numerous fossil fish in the world. In fact, it is likely the most common vertebrate fossil ever. It is thus no surprise that Wooster has dozens of specimens, most of them donated by students and alumni.

Knightia lived in freshwater lakes throughout western North America during the Eocene. It is closely related to herring and sardines, and almost certainly had similar life habits. We know that it lived in large schools, and we suspect it had a diet of phytoplankton and insect larvae. It was low on the ecological food chain, just like its modern cousins, and so was an important food source for all sorts of larger fish, reptiles, birds and mammals.
We tend to see most often beautifully preserved, complete Knightia specimens like the one at the top of the page. This is because if a fossil is very common, collectors can afford to keep only the best specimens. It is fun, though, to see what the average Knightia looks like in the fossil record. Above is a specimen collected by our petrologist Meagen Pollock from an outcrop in Wyoming. Note that the fish are contorted and often overlapping — specimens that are usually discarded by collectors. This slab shows better that these fossils occur in vast, complicated, messy death assemblages, probably because of volcanic ash falls or quick changes in lake chemistry.
This is a digital reconstruction of Knightia (© N. Tamura). Note the deeply forked tail and flattened top of the head.

Knightia was named in 1907 by the accomplished and very problematic David Starr Jordan (1851-1931). Jordan was a well known fish expert, having been inspired by the iconic ichthyologist Louis Agassiz himself. He taught at several colleges and universities, eventually serving as president of Indiana University (at 34, the youngest university president at the time) and as the first president of Stanford University. He was a very successful university president, especially in the first years of Stanford.

But, but … David Starr Jordan was also a eugenicist, believing in compulsory sterilization of the “unfit”. On the bright side (if there is one here), he opposed war because it tended to kill the most fit members of society. Jordan also shockingly covered up the apparent murder of Jane Stanford, co-founder of the university, in 1905. Jordan does not look good at all in that story, most of which was sorted out only about ten years ago. Who would have guessed that a murder mystery could lurk in the taxonomic history of these pretty little fish?

References:

Grande, L. 1982. A revision of the fossil genus Knightia, with a description of a new genus from the Green River Formation (Teleostei, Clupeidae). American Museum Novitates 2731: 1-22.

Jordan, D.S. 1907. The fossil fishes of California; with supplementary notes on other species of extinct fishes. Bulletin, Department of Geology, University of California 5:136.

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Mark Wilson March 24th, 2013

This small oyster is not in itself unusual. In fact, it is one of the most common fossils in the Jurassic of western Europe: Praeexogyra acuminata (Sowerby, 1816). It may be better known by its older name: Ostrea acuminata. Local collectors call it the “sickle oyster” because of its curved shape. This specimen is from the Sharp’s Hill Formation (Middle Bathonian) exposed in the Snowshill Quarry near Moreton-in-Marsh, Gloucestershire, England. I collected it on my first trip to England in 1985.
What attracted me to this particular shell can be seen in the above close-up: lots of little straight lines incised across its outer surface (along with a serpulid worm tube). The lines were scraped by the Aristotle’s Lantern of one or more regular echinoids (sea urchins). This is the trace fossil Gnathichnus pentax Bromley, 1975. We met this fossil last month cut into a Cretaceous oyster from Israel. One or more echinoids grazed over this Jurassic oyster, probably consuming algae and other organic materials.

Praeexogyra acuminata was an epifaunal filter-feeder, meaning it lived on the substrate sucking in seawater and sorting from it organic material for food. During the Middle Jurassic these oysters were so common that their shells formed thick deposits. It is possible that some deposits rich in these shells were formed in brackish waters rather than under fully marine conditions.

Ostrea acuminata was named by by the enthusiastic English natural historian James Sowerby (1757-1822). We met him earlier as the author of a Cretaceous bivalve genus.

References:

Bernard-Dumanois, A. and Delance, J-H. 1983. Microperforations par algues et champignons sur les coquilles des «Marnes à Ostrea acuminata (Bajocien supérieur) de Bourgogne (France), relations avec le milieu et utilisation paléobathymétrique. Geobios 16: 419-429.

Bernard-Dumanois, A. and Rat, P. 1983. Etagement des milieux sédimentaires marins. Paléoécologie des Huîtres dans les “Marnes à Ostrea acuminata” du Bajocien de Bourgogne (France). Comptes rendus de l’Académie des sciences Paris 296: 733-737.

Hudson, J.D. and Palmer, T.J. 1976. A euryhaline oyster from the Middle Jurassic and the origin of true oysters. Palaeontology 19: 79-93.

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Mark Wilson March 17th, 2013

The above is one of my favorite “fossils”, a commercially-available cast of the lower jawbone of Gigantopithecus blacki, a giant extinct ape. It was produced from an actual Pleistocene fossil found in a cave near Liucheng, Guangxi, in southern China. I like it especially because it is sometimes associated with the mythical “Bigfoot”.

Gigantopithecus blacki was the largest ape that ever lived: up to three meters tall and weighing over 500 kilograms. (G. blacki is known only from teeth and mandibles such as that shown above, so these size estimates are based on scaling.) It was a contemporary with early versions of our own species, which must have led to a few astounding encounters for our ancestors. G. blacki was two or three times heavier than the largest gorillas today.

Gigantopithecus blacki appears to have lived in bamboo forests. Striations on its teeth, and the occasional phytolith stuck in the enamel, shows that this species was a vegetarian. It may have even had a lifestyle much like today’s pandas.

The molars of Gigantopithecus blacki look surprisingly like ours with their multiple cusps and broad surfaces. This is the result of convergent evolution and not an indication of a recent common ancestry. (They are analogous features, not homologous.) G. blacki is now classified in the Subfamily Ponginae with their cousins the orangutans.

What is most fun about Gigantopithecus these days is its association with the “Bigfoot” illusion. Look at how seriously the people at the “Bigfoot Field Researchers Organization” take the possible connection of Gigantopithecus and Bigfoot. Despite their objections, we really can wonder why we’ve never found evidence of this giant ape in North America, including bones, teeth, legitimate footprints or real photographs. A living three-meter tall ape is a bit difficult for science to have missed! (Unless, of course, Bigfoot has supernatural powers.)

References:

Coichon, R. 1991. The ape that was – Asian fossils reveal humanity’s giant cousin. Natural History 100: 54–62.

Ciochon, R., et al. 1996. Dated co-occurrence of Homo erectus and Gigantopithecus from Tham Khuyen Cave, Vietnam. Proceedings of the National Academy of Sciences of the United States of America 93: 3016–3020.

Jin, C., et al. 2009. A newly discovered Gigantopithecus fauna from Sanhe Cave, Chongzuo, Guangxi, South China. Chinese Science Bulletin 54: 788-797.

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Mark Wilson March 10th, 2013

Wooster geologists have again greatly benefited from the donation of a collection by an alumnus. George Chambers (’79), a successful professional photographer, sent us several boxes of minerals, rocks and fossils he had acquired in his lifelong passion for geology. (George was a geology major at Wooster in the class just after mine.) Among the many world-class specimens he gave us are two fossil ophiuroids (brittle stars). They are Ophiopetra lithographica Enay and Hess, 1962, from the Lower Hienheim Beds (Lower Tithonian, Upper Jurassic) near Regensburg, Germany. They are part of the “Fossillagerstätte Hienheim“, a preserved brittle star ecosystem in a lagoon at the edge of a Late Jurassic sea. This is the same set of lithographic limestones in which the famous bird fossil Archaeopteryx was found.
In both these images you see the spiny arms of the brittle stars twisted about. It is their flexibility and snake-like movements in life that provoked the scientific name ophiuroids (serpent-forms) for the brittle stars. The “brittle” term comes from their ability to autotomize (spontaneously detach) their arms when threatened, leaving a squirming distraction for a predator as they escape.
Ophiopetra lithographica is probably the most common fossil brittle star known. It was preserved by the countless millions in these Jurassic lagoons in Germany. Most geologists believe they were buried by fine-grained carbonate sediment suspended by sudden storms. As you can see in the above close-up, the preservation of the plates and spines is remarkable.

Most brittle stars are suspension feeders (sorting out food particles from the water), deposit feeders (eating organic material in the sediment) or scavengers. Ophiopetra lithographica may have been a carnivore with its heavily-spined arms and strong jaws. It likely ate small arthropods on the seafloor.

The evolution of brittle stars is interesting and controversial. They were relatively common in the Paleozoic and then just barely survived the Permian extinctions. Their rapid evolution into a variety of taxa in the Mesozoic and Cenozoic has led to many debates about their phylogeny. Even the placement of Ophiopetra into a family is a problem. Does it belong to the Family Aplocomidae where it was originally placed or to the older Family Ophiolepididae as has been recently suggested?

Our students will enjoy these fine fossils in the invertebrate paleontology course. They have doubled our collection of brittle stars! Thank you again to George Chambers for his thoughtfulness and generosity.

References:

Enay, R. and Hess, H. 1962. Sur la découvertes d’Ophiures (Ophiopetra lithographica n.g. n.sp.) dans le Jurassique supérieur du Haut-Valromey (Jura méridional). Eclogae geologicae Helvetiae 55: 657-678.

Hess, H. and Meyer, C.A. 2008. A new ophiuroid (Geocoma schoentalensis sp. nov.) from the Middle Jurassic of northeastern Switzerland and remarks on the Family Aplocomidae Hess 1965. Swiss Journal of Geosciences 101: 29-40.

Röper, M. and Rothgänger, M. 1998. Die Plattenkalke von Hienheim (Landkreis Kelheim) – Echinodermen-Biotope im Südfränkischen Jura. Eichendorf (Eichendorf Verlag), 110 S.

Stöhr, S. 2012. Ophiuroid (Echinodermata) systematics—where do we come from, where do we stand and where should we go? In: Kroh, A. and Reich, M. (Eds.) Echinoderm Research 2010: Proceedings of the Seventh European Conference on Echinoderms, Göttingen, Germany, 2–9 October 2010. Zoosymposia, 7: 147-161.

Thuy, B., Klompmaker, A.A. and Jagt, J.W.M. 2012. Late Triassic (Rhaetian) ophiuroids from Winterswijk, the Netherlands; with comments on the systematic position of Aplocoma (Echinodermata, Ophiolepididae). In: Kroh, A. and Reich, M. (Eds.) Echinoderm Research 2010: Proceedings of the Seventh European Conference on Echinoderms, Göttingen, Germany, 2–9 October 2010. Zoosymposia, 7: 163-172.

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