One of the many diverse results of being a geology major: the adventures of Will Driscoll (’05) in evolutionary ecology

Mark Wilson March 6, 2013 10:38 am

WillDriscoll05_030513WOOSTER, OHIO–Yesterday Greg Wiles and I attended a Biology Department Seminar given by our former student Will Driscoll (Geology ’05). Will was in all our standard departmental courses and did his Independent Study project with Dr. Wiles in dendrochronology. Yet here he was giving a presentation to the Biology Department. How did this happen? It is yet another example of the utility of a liberal arts major in science … and what persistence and great ideas can lead you.

I well remember the day during Will’s senior year that he brought me an essay he wanted me to read. For one thing, it was an essay unconnected with any course — Will just wanted to write down some ideas and get a response. The essay was about evolutionary ecology and morphogenesis. To say this came from left field would be an understatement. I had no idea Will had such concepts, and they were extremely well developed and expressed. Will applied to the Department of Ecology and Evolutionary Biology at The University of Arizona (the top program in the nation for this subject). He finished his PhD there last year and is now a Postdoctoral Research Fellow in the Département de Biologie, École Normale Supérieure, Paris, France. That is a long way from Scovel Hall!

WillImage030613 copy

A small swarm of toxic Prymnesium parvum (small golden cells) attacks a rotifer accustomed to grazing on unicellular algae. The toxic algae help themselves to a meal, and in the process help all of the algae that the rotifer might have otherwise eaten. (Image and caption from Will Driscoll.)

Will’s specialty, and the topic of his seminar yesterday, is in a broad sense on “the ecological drivers and consequences of multilevel selection”. He is pursuing this interest now with studies on what has been called “microbial sociobiology”. The title of his Wooster talk was “The ecological consequences of microbial sociality”. He is looking at the behavior of microbes as cooperative groups and all this means for evolution and ecology. His stories about toxic bloom-forming algae were amazing, opening up new dimensions on how to place single-celled organisms into our models of behavioral evolution. Will himself can tell you much more about his research and ideas on his website.

Will’s presentation was inspiring at (appropriately) multiple levels: the science was novel, fascinating and provocative, and Will’s enthusiasm and skills reminded us yet again why teaching at Wooster is simply the best job in the world.

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Wooster’s Fossils of the Week: More bryozoan etchings and an African slug surprise

Mark Wilson March 3, 2013 1:45 am

CheilostomeEtchings2_585This is the inside of a modern cockle shell (Dinocardium vanhyningi) found on a beach in Wilmington, North Carolina. Across the surface is a radiating series of pits, each of which was formed under a zooid of an encrusting cheilostome bryozoan colony, much like Ropalonaria described last week. This etched shell gives me an opportunity to tell a cautionary tale of trace fossils, slugs and taxonomy.
pdt12291This scanning electron microscope image was taken by my friend and colleague Paul Taylor at The Natural History Museum in London. It shows a cheilostome bryozoan etching (the elongated pits) across a shell surface very much like the modern shell at the top of the page. In the lower right is a bit of the cheilostome bryozoan Amphiblestrum. This particular bryozoan did not make the pits themselves (it is oriented in a different direction), but another colony of the same species likely did. This assemblage comes from the Coralline Crag Formation (Pliocene) exposed in Broom Pit, Suffolk, England.

In 1999, Paul Taylor, Richard Bromley and I published a paper in the journal Palaeontology describing these bryozoan etching pits as a new ichnogenus (a category of trace fossil) with a Late Cretaceous to Holocene range. We invented (or so we thought) the name Leptichnus using the Greek roots leptos (‘flimsy, delicate, subtle’) and ichnos (‘track, footprint’). It was a fun little project, and we provided a useful name to embed this fossil in the literature.

This past fall, thirteen years after publication, I decided to write a Fossil of the Week entry on Leptichnus. In my innocence I searched Google for “Leptichnus” and was very surprised to find it has a Wikipedia page — and it was an East African slug! Yes, the beautiful name Leptichnus was preoccupied by a urocyclid terrestrial gastropod, Leptichnus Simroth, 1896, found in Kenya and Tanzania. 1896 is a long time before 1999, so Simroth’s name has priority over ours. The ichnogenus Leptichnus Taylor, Wilson and Bromley, 1999, thus became a junior homonym of the gastropod genus Leptichnus Simroth, 1896. We had to come up with a new name for it.
LeptichnusOriginalDescription_585 copyAbove is the original 1896 description of Leptichnus The Slug by Heinrich Rudolf Simroth (1851-1917). He apparently came up with the name because this shell-less snail left a subtle trail behind it when it slithered. It is the first time I’ve seen the -ichnus suffix used for anything but a trace fossil.
Heinrich_Simroth_1902Herr Doktor Professor Simroth was a German zoologist and malacologist educated at the University of Leipzig. He was a schoolteacher for his whole career, doing prodigious research in his spare time. His speciality was, unsurprisingly, terrestrial slugs. He worked on specimens brought back by scientific expeditions, including one in the short-lived colony of German East Africa. It is from this collected material he described Leptichnus. Simroth’s type collection was long considered lost, but many specimens were recently rediscovered in Berlin (Glaubrecht, 2010). These do not, alas, include any representatives of Leptichnus. The image above is of Simroth in 1902.

Taylor, Wilson and Bromley (2013) proposed the new name Finichnus to replace Leptichnus Taylor, Wilson and Bromley, 1999. To preserve the meaning of the original name, we substituted the Greek finos (‘fine, delicate’) for leptos.

The lesson of this story? Search, search, search for homonyms of new taxonomic names. In our defense, searching wasn’t as easy back in the 90s (Google’s search engine came online in 2000, for example, and Wikipedia began in 2001). At least the adventure introduced us to Heinrich Rudolf Simroth and his slugs!

References:

Glaubrecht, M. 2010. Slug(-gish) science, or an annotated catalogue of the types of tropical vaginulid and agriolimacid pulmonates (Mollusca, Gastropoda), described by Heinrich Simroth (1851–1917), in the Natural History Museum Berlin. Zoosystematics and Evolution 86: 15–335.

Rosso, A. 2008. Leptichnus tortus isp. nov., a new cheilostome etching and comments on other bryozoan-produced trace fossils. Studi Trentini – Acta Geologica 83: 75–85.

Simroth, H. 1896. Über bekannte und neue Urocycliden. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft 19: 281–312.

Taylor, P.D., Wilson, M.A. and Bromley, R.G. 1999. Leptichnus, a new ichnogenus for etchings made by cheilostome bryozoans into calcareous substrates. Palaeontology 42: 595–604.

Taylor, P.D., Wilson, M.A. and Bromley, R.G. 2013. Finichnus, a new name for the ichnogenus Leptichnus Taylor, Wilson and Bromley, 1999, preoccupied by Leptichnus Simroth, 1896 (Mollusca, Gastropoda). Palaeontology (in press).

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The Dendrochronology Team of Wooster Geologists makes its television debut

Mark Wilson February 28, 2013 8:46 pm

Gwiles022813a“Barn Detectives” is a recent episode of the television show Our Ohio, and it features Dr. Greg Wiles and his team of crack dendrochronologists. You can view the video by clicking the link. It is very well done. The project described in the program is the dating of the Emerson barn in Apple Creek, Ohio. These Wooster scientists study the tree rings in the beams which were used in the original structure. Careful analysis of these rings will show the year the old-growth trees were cut for timber, and thus the date of the building. This work not only gives the Emerson family a date for a treasured building, it also provides additional dendrochronological data for studying climate change in the last two centuries.

Nwiesenberg022813Our geological technician Nick Wiesenberg provides explanations of the process from the barn, a local old-growth forest (Johnson Woods, see above), and the dendrochronology lab at Wooster.

lvargo022813Geology senior Lauren Vargo describes the value of tree rings for climate history, and is shown in several action shots of coring and sanding.

anash022813Andy Nash, another geology senior, describes the construction of “floating chronologies” from tree cores that are eventually tied to the larger dendrochronological record to give dates to the wood. (With an accuracy, as Greg likes to say, of “plus or minus zero years”.)

gwiles022813bBack in the lab, Greg shows how the cores from the Emerson barn are counted and measured with our video microscope system. On the monitor is a magnified view of rings from the Emerson barn.

nwiesenberg022813bNick had the honor of announcing the calculated date the trees were cut to make the barn’s beams: (Spoiler Alert!) the Fall of 1845. The ground would have been hard then and the farmers would have had time to collect materials for the construction.

It was great fun to see our students and colleagues explain their work so well, and to show the world the enthusiasm and professional skills of Wooster’s dendrochronologists.

The full “Barn Detectives” video is available on YouTube at this link.

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Wooster’s Fossil of the Week: A bryozoan etching (Upper Ordovician of Indiana)

Mark Wilson February 24, 2013 1:27 am

Ropalonaria_venosa_585_010213Another trace fossil of a sort this week. Above you see the dorsal valve exterior of a strophomenid brachiopod from the Upper Ordovician of southeastern Indiana. Across the surface is a network of grooves looking a bit like a spider web. This is a feature formed when a soft-bodied ctenostome bryozoan colony etched its way down into the shell it was encrusting. Ropalonaria venosa Ulrich, 1879 is the official name of this fossil.
Ropalonaria_close_010513Above is a closer view of the same Ropalonaria venosa. Tiny crystals of yellow dolomite fill the excavations. The ctenostome bryozoan that made it had no skeleton and used some sort of chemical to dissolve the shell beneath it. The fidelity of this etching is good enough to identify various details of the colony structure and zooecial form. This is where our fossil classification system goes a bit awry: Is Ropalonaria a trace fossil (evidence of animal activity) or a kind of external mold of the original organism? Arguments have been made for each category, and the name Ropalonaria shows up on lists of both trace fossils and body fossils.
Ulrich_EO_1927Ropalonaria venosa is the type species of the genus Ropalonaria erected by Edward Oscar Ulrich in 1879 (above in 1927). E.O. Ulrich, as he is better known, was one of the most colorful and controversial geologists of the late 19th and early 20th century. He was born in Covington, Kentucky, in 1857. Covington is across the Ohio River from Cincinnati, Ohio, and is undergirded by the famous fossiliferous limestones and shales of the Cincinnatian Group (Upper Ordovician). Ulrich started as a child collecting fossils in the region. He was an early member of the Cincinnati Society of Natural History, often bringing fossils to meetings for identifications. (There he met another young man very interested in fossils: the future paleontologist Charles Schuchert. Schuchert was the advisor of my advisor’s advisor, so he’s in my “academic genealogy”.)

Ulrich took courses at German Wallace College (today’s Baldwin Wallace University in Berea, Ohio) and the Ohio Medical College. He had an eclectic youth exploring all sorts of topics, from opera to spiritualism, but always kept geology and fossils close to his heart. He had an adventurous stint as a superintendent in a Colorado silver mine. Returning back east, Ulrich became an enormously productive geologist with the geological surveys of Illinois, Minnesota, and Ohio. He was President of the Paleontological Society in 1915. In 1931 he received the Mary Clark Thompson Medal from the National Academy of Sciences, and the next year the Geological Society of America awarded him the prestigious Penrose Medal. He died in 1944 in Washington, D.C.

E.O. Ulrich is still a polarizing figure in American geology. He is famous for resisting the modern concept of facies in sedimentary geology, preferring a concept now known as “layer cake stratigraphy“. (In his defense, the rocks in the Cincinnati area really do fit much of his model; his error was extending it much too far.) Ulrich also has a reputation as a bit of a “splitter” in paleontology. (Someone who makes more species than necessary by “splitting” groups into smaller subgroups.)

Despite what we think of E.O. Ulrich today, his paleontological contributions have mostly held up, including the description of the intriguing fossil Ropalonaria.

References:

Bassler, R.S. 1944. Memorial to Edward Oscar Ulrich. Proceedings of the Geological Society of America for 1944: 331–351.

Pohowsky, R.A. 1978. The boring ctenostomate Bryozoa: taxonomy and paleobiology based on cavities in calcareous substrata. Bulletins of American Paleontology 73(301): 192 p.

Ruedemann, R. 1946. Biographical memoir of Edward Oscar Ulrich, 1857-1944. National Academy of Sciences of the United States of America. Biographical Memoirs, Volume XXIV, 7th Memoir, 24 pp.

Ulrich, E.O. 1879. Descriptions of new genera and species of fossils from the Lower Silurian about Cincinnati: Journal of the Cincinnati Society of Natural History 2: 8-30.

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Celebrating the achievements of Wooster Geologists

Mark Wilson February 21, 2013 9:32 pm

2013Geo AwardWinners

WOOSTER, OHIO –One of the pleasures of being the chair of the Geology Department at Wooster is that I get to go to the annual college Awards Banquet with some of our best students. Tonight we celebrate three young women who have done especially well at Wooster. On the left is Whitney Sims (’13) of Maple Heights, Ohio. She received the Charles B. Moke Prize, which is a “field instrument or device” awarded to the graduating senior who has shown the greatest improvement during his or her college career. (Whitney’s award was a new iPad — coolest prize of the evening.) In the middle is Tricia Hall (’14) of Marion, Ohio. She won the Karl Ver Steeg Prize in Geology and Geography, which goes to the geology major who has the highest standing in the middle of the junior year. On the right is Kit Price (’13) of Ann Arbor, Michigan. Her award was the Robert W. McDowell Prize in Geology for having the highest general standing among geology majors in the junior and senior years.

Congratulations to Whitney, Tricia and Kit! We are very proud of them and all our Wooster Geologists.

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Wooster’s Fossil of the Week: Encrusting tubes from the Devonian of Michigan

Mark Wilson February 17, 2013 1:52 am

HederelloidSEM_DevMIThe scanning electron microscope (SEM) image above shows the tubes of the encrusting group known as hederelloids. They are among my favorite fossils. I was reminded of them recently while reading this advertisement for a novel in which, to my great surprise, hederelloids are a primary part of the plot! A mysterious black “fouling” destroys shipping. Scientists discover that it is made by a group long thought to be extinct — the hederelloids! There is even a page talking about the “science” behind the story. (Although I would think if they were serious they would spell “bryozoan” correctly.)
HederellaOH3The hederelloids are a group of colonial encrusting organisms found from the Silurian through the Permian, with possible members in the Ordovician and the Triassic (Taylor and Wilson, 2008). They were entirely marine and were most common by far on Devonian brachiopods and corals. They are “runner-like” encrusters, meaning they grew sequentially across the substrate budding out new members of the colony. Their zooids (the skeletons that contained the individuals) are usually curved and made of microprismatic calcite secreted from the inside only. (This latter feature meant they could repair damage such as boreholes with patches from the inside; see Wilson and Taylor, 2006). The specimen above is a Devonian spiriferid brachiopod from northwestern Ohio with a hederelloid colony encrusting the dorsal valve.
HedsSEMpdtDevNYHederelloids were very diverse in their time. The SEM image above (courtesy of Paul Taylor at the Natural History Museum, London) shows at least two types of hederelloid on a rugose coral from the Devonian of New York. The large tube at the bottom has several lateral buds. At the very top of the view you can see a much smaller hederelloid growing in the opposite direction.
DevonianIowaHederelloidUSNM78639The earliest workers on hederelloids thought that they were cyclostome bryozoans of some type (see Bassler, 1939). They look superficially like the common genera Corynotrypa, Cuffeyella and Stomatopora. Hederelloids, though, are significantly larger on the whole, they do not bud in the same pattern as bryozoans, and they do not have lamellar walls. Their shell microstructure and budding patterns suggests instead that they may be related to the phoronids, making them a kind of lophophorate (lophophore-bearing organism; the lophophore is a tentacular feeding device). They could probably, like bryozoans, retract the lophophore into their tubes when necessary. The above photograph shows the underside of a hederelloid colony from the Devonian of Iowa. Note the distinctive budding pattern. The scattered spirals are microconchids.

HedCloseUpDevNYThis is a nice collection of hederelloids from the Devonian of New York. Notice the diversity of sizes, shapes and budding patterns. How can you not be fascinated by such enigmatic little creatures?

References:

Bassler, R.S. 1939. The Hederelloidea. A suborder of Paleozoic cyclostomatous Bryozoa. Proceedings of the United States National Museum 87: 25-91.

Taylor, P.D. and Wilson, M.A. 2008. Morphology and affinities of hederelloid “bryozoans”, p. 301-309.  In: Hageman, S.J., Key, M.M., Jr., and Winston, J.E. (eds.), Bryozoan Studies 2007: Proceedings of the 14th International Bryozoology Conference, Boone, North Carolina, July 1-8, 2007.  Virginia Museum of Natural History Special Publication 15.

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

Wilson, M.A. and Taylor, P.D. 2006. Predatory drillholes and partial mortality in Devonian colonial metazoans. Geology 34:565-568.

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Wooster’s Fossil of the Week: Sea urchin bites from the Upper Cretaceous of southern Israel

Mark Wilson February 10, 2013 1:16 am

GnathichnusCenomanian020413_585What you see above is a bit of oyster shell with some curious small gouges in it. The oyster is Ilymatogyra (Afrogyra) africana (Lamarck, 1801) from the En Yorqe’am Formation (Cenomanian) exposed in Hamakhtesh Hagadol, southern Israel. The deep scratches are the trace fossil Gnathichnus pentax Bromley, 1975. As you can just make out in the lower center of the image, the grooves are overlapping series of five-pointed stars. That’s what makes this trace so cool — the stars were made by the unique feeding apparatus of a regular echinoid (sea urchin).
Strongylocentrotus_purpuratus_020313_585This is the business end of the modern sea urchin Strongylocentrotus purpuratus (a preserved specimen in Wooster’s collection). You see here in the center the peristome, which is a circle of plates surrounding the mouth, with the sharp five-sided teeth protruding from the echinoid’s Aristotle’s Lantern. These animals slowly graze across hard substrates, using their teeth to scrape the surfaces for algae, fungi and adherent organisms like diatoms. The biting actions of the Aristotle’s Lantern produce the star-shaped incisions we know as the trace fossil Gnathichnus pentax.

I briefly sampled and studied an exposure of the fossiliferous En Yorqe’am Formation in 2003 during my first visit to Israel. The oyster shells in this unit provide one of the few examples of hard substrate communities in the tropics of the Late Cretaceous. The encrusters include ostreid and spondylid bivalves, the cyclostome bryozoan Stomatopora, and the agglutinating foraminiferan Acruliammina. Borings include those of barnacles (Rogerella elliptica) and sponges (Entobia aff. E. megastoma). There is also a sea urchin present (Heterodiadema lybicum) that was almost certainly the maker of the Gnathichnus pentax traces.

References:

Bromley, R.G. 1975. Comparative analysis of fossil and recent echinoid bioerosion. Palaeontology 18: 725-739.

Wilson, M.A. 2003. Paleoecology of a tropical Late Cretaceous (Cenomanian) skeletozoan community in the Negev Desert of southern Israel. Geological Society of America Abstracts with Programs 35(6): 420.

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Women scientists at Wooster, featuring Wooster Geologist Shelley Judge

Mark Wilson February 7, 2013 11:22 am

Dr. Shelley Judge begins this excellent short video about women in science at Wooster:

Screen Shot 2013-02-07 at 10.20.43 AM(You have to click the link I made in the text above. Embedding a video in a blog post is beyond my skills!)

We’re proud of all the women scientists at Wooster, past, present and future!

 

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Wooster’s Fossil of the Week: A very thin coral from the Upper Ordovician of Indiana

Mark Wilson February 3, 2013 1:50 am

Protaraea111712What we have above is a heliolitid coral known as Protaraea richmondensis Foerste, 1909. It has completely encrusted a gastropod shell with its thin corallum. Stephanie Jarvis, a Wooster student at the time and now a graduate student at Southern Illinois University, found this specimen during her paleontology class field trip to the Whitewater Formation exposed near Richmond, Indiana.

Protaraea is a confusing taxon to my Invertebrate Paleontology students. It is a very common encruster in their Ordovician field collections, being found on hard substrates as varied as rugose corals and orthid brachiopods. It is so thin, though, that it is hard to believe it was a colonial coral. Plus it has tiny septa (vertical partitions) in its corallites (the holes that held the polyps), very unlike most corals of the heliolitid variety. This is a group the students have to identify by matching pictures and taking our word for it.

We can’t identify the gastropod underneath. Note that it has a sinus evident in the last whorl (an open slot parallel to the coiling). The coral grew right up to the edge of this sinus, preserving it and its extension through the shell.

References:

Alexander, R.R. and Scharpf, C.D. 1990. Epizoans on Late Ordovician brachiopods from southeastern Indiana. Historical Biology 4: 179-202.

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

Mõtus, M.-A. and Zaika, Y. 2012. The oldest heliolitids from the early Katian of the East Baltic region. GFF 134: 225-234.

Ospanova, N.K. 2010. Remarks on the classification system of the Heliolitida. Palaeoworld 19: 268–277.

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Stratigraphy and paleoenvironments of the Soeginina Beds (Paadla Formation, Lower Ludlow, Upper Silurian) on Saaremaa Island, Estonia (Senior Independent Study Thesis by Richa Ekka)

Mark Wilson January 28, 2013 3:37 pm

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Editor’s note: Senior Independent Study (I.S.) is a year-long program at The College of Wooster in which each student completes a research project and thesis with a faculty mentor.  We particularly enjoy I.S. in the Geology Department because there are so many cool things to do for both the faculty advisor and the student.  We post abstracts of each study as they become available.  The following was written by Richa Ekka, a senior geology major from Jamshedpur, India. She finished her thesis and graduated in December, so her work is the first of her class to be posted. You can see earlier blog posts from Richa’s study by clicking the Estonia tag to the right.

In July 2012, I travelled to Estonia with my advisor, Dr. Mark Wilson, a fellow Wooster geology major Jonah Novek, Dr. Bill Ausich and three geology students of The Ohio State University. It was quite an adventure with a few unexpected changes in our travel plans. Dr. Wilson and I had to spend a day in Tallinn, waiting for Jonah as his flight was delayed. Upon Jonah’s arrival we headed for the island of Saaremaa, where I carried out my research. We stayed in Kuressaare, on the southern shore of the island. I did my field research on the Soeginina Beds at Kübassaare in eastern Saaremaa.

The Kübessaare coastal area is an outcrop of the Soeginina Beds in the Paadla Formation (lowermost Ludlow) that represents a sequence of dolostones, marls, and stromatolites (see figure above). The Soeginina Beds represent rocks just above the Wenlock/Ludlow boundary, which is distinguished by a major disconformity that can be correlated to a regional regression on the paleocontinent of Baltica. The occurrence of these sedimentary structures and fauna in the Soeginina Beds provide us with evidence that there was a change in paleoenvironmental conditions from a shelfal marine environment to a restricted shallow marine setting followed by a hypersaline supratidal setting.

The base of the section has Chondrites trace fossils and marly shale that represent a shelfal marine environment. The next section on top has dolostones with Herrmannina ostracods, oncoids, and eurypterid fragments that indicate a shallow marine setting (lagoonal). The next section above has stromatolites (see figure below) that form in exposed intertidal mud flats. The topmost section has halite crystal molds that represent a hypersaline supratidal setting. Thus, we see a change from shelfal marine environment to a restricted shallow marine setting and finally to a hypersaline supratidal setting.

DSC_0367

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