Mark Wilson January 2nd, 2011
We’re going to start 2011 with a new blog feature: Fossil of the Week! My colleagues, of course, are welcome to also start “Mineral of the Week”, “Structural Geologic Feature of the Week”, or “Climate Event of the Week”. The more the better to keep our blog active through the winter!
This week’s fossil was collected by Brian Bade of Sullivan, Ohio, and donated to Wooster as part of my hederelloid project. It is a beautiful specimen of the tabulate coral Aulopora encrusting a brachiopod valve from the Silica Shale (Middle Devonian — about 390 million years old) of northwestern Ohio. Auloporid corals are characterized by an encrusting habit, a bifurcating growth pattern, and horn-shaped corallites (individual skeletal containers for the polyps).
What is especially nice about this specimen is that we are looking at a well preserved colony origin. The corallite marked with the yellow “P” is the protocorallite — the first corallite from which all the others are derived. You can see that two corallites bud out from the protocorallite 180° from each other. These two corallites in turn each bud two corallites, but at about 160°. This pattern continues as the colony develops (a process called astogeny). The angles of budding begin to vary depending on local obstacles; they never again go below 160°.
The polyps inside the corallites are presumed to have been like other colonial coral polyps. Each would have had tentacles surrounding a central opening, and all were connecting by soft tissue within the skeleton. They likely fed on zooplankton in the surrounding seawater. This type of coral went extinct in the Permian, roughly 260 million years ago.
Again, we thank our amateur geologist friends for such useful donations to the research and educational collections in the Geology Department at Wooster.
Mark Wilson November 26th, 2010
WOOSTER, OHIO — Last weekend we picked up another load of rocks, minerals and fossils donated by the family of one of our loyal alumni. We will be sorting through them for months getting them ready for displays and our teaching collections. Among the treasures are large numbers of particular items, especially fossils. I want to highlight two of many such sets. The trilobites are Phacops bufo from the Silica Shale (Devonian) of northeastern Ohio; the belemnites below are from the Jurassic of Wyoming. (Belemnites from the Upper Cretaceous of Germany and the Jurassic of Israel have been featured in this blog, as have beautiful trilobites from the Middle Cambrian of British Columbia, Canada.) Numerous nearly-identical fossils such as these play an important role in our teaching. We can, for example, have a fossil in front of each student during lectures for immediate reference (and quizzing!). It is also possible to have biometric measuring exercises in our labs with these fossil “populations” of particular species. Gifts again put to work in education!
Mark Wilson October 13th, 2010
Crinoid holdfasts and bryozoans on a cobble from the Ordovician of northern Kentucky.
WOOSTER, OHIO–Today we are celebrating the first annual National Fossil Day (or at least I am!). Be sure to check out that link from the National Park Service — it contains the official National Fossil Day song! My recognition of this special day is to post some photographs of nice fossil specimens from the Wooster collections. You can find larger versions of these photos — and hundreds more — on my Wikimedia page. Here’s to fossils: beautiful messengers from the distant past.
Shark teeth (Scapanorhynchus) from the Upper Cretaceous of southern Israel. These were collected by Andrew Retzler ('11).
Rudist bivalves from the Upper Cretaceous of the Omani Mountains.
Tentaculitids from the Devonian of Maryland.
Thecideide brachiopods, cyclostome bryozoans and serpulids encrusting a bivalve shell from Zalas Quarry (Jurassic: Callovian-Oxfordian) in southern Poland.
Fossil leaf (Viburnum lesquereuxii) with insect damage; Dakota Sandstone (Cretaceous) of Ellsworth County, Kansas.
Mark Wilson October 10th, 2010
Brian Bade in the midst of his fossil collection and paleontological library.
SULLIVAN, OHIO–Last month I gave a talk to the North Coast Fossil Club about an obscure fossil group, the hederelloids. My purpose, besides simply enjoying the good company of fossil enthusiasts, was to show the audience a type of small and encrusting fossil they have all collected but probably didn’t notice because these creatures do not (at least to the naked eye) look very interesting. Sure enough, many in the club remembered seeing these fossils, and some had learned a considerable amount about them. Members began to send me specimens in the mail for further study.
One gentleman, though, told me he had hundreds of hederelloid fossils on Devonian brachiopods and corals collected in Ohio, Michigan and Ontario — and that I was welcome to use whatever specimens I needed to advance the science. Today I visited Brian Bade in nearby Sullivan, Ohio. His collection of these fossils and many more astounded me. He has thousands of specimens, matched with an extensive paleontological library. The fossils are very well curated (that is, we can easily tell the collecting localities and stratigraphic horizons) and expertly prepared. Brian is generous with his treasures and wants nothing more than to see them used in scientific studies. I borrowed several dozen encrusted brachiopods and corals to get started on a hederelloid taxonomy project.
Brian Bade with one of many, many drawers of specimens.
Brian is an excellent example of why amateur fossil paleontologists are essential to the progress of professional paleontology. He has a very keen eye for finding fossils and keeping them in their proper geological context (“provenance”). He instinctively can tell which specimens may be most interesting to science, and he shares with the professionals an appreciation for their beauty and rarity. Brian knows how to work with landowners and quarry managers to make sure access to fossil sites is maintained, which is a skill sometimes lacking in casual collectors. Amateur paleontologists often have far more time for fieldwork than the professionals, and usually have more experience in sorting out particular kinds of fossils in their specialties. Many paleontological studies rely upon the skills of amateurs to provide the raw data. Indeed, “amateur paleontologist” is not quite the right title considering the knowledge base and experience these men and women have accumulated. I prefer to call them simply “paleontologists”.
Devonian brachiopods in one of Brian's drawers. This year's paleontology class can now identify them from here!
Mark Wilson September 11th, 2010
PARMA, OHIO–This afternoon I gave a talk at a meeting of the North Coast Fossil Club in this suburb of Cleveland. I chose the poorly-known fossil group called hederelloids as my topic because I knew that many people in that enthusiastic group had likely seen and collected them without knowing. They are very common encrusters on Devonian fossils, especially brachiopods, corals and bryozoans from the Middle Devonian of northwestern Ohio. I was not disappointed as several keen members brought me specimens from their collections or told me about large numbers of hederelloids they can send to me for study. Paul Taylor and I have been studying hederelloids for the past five years (as far as I know we are the only paleontologists in this little subfield!) and believe they may hold a key to some curious events in the Devonian and may expand what we know about lophophorate evolution. We need many more specimens, though, for our systematic work. The hard-working, knowledgeable amateur paleontologists in the North Coast Fossil Club are now going to help! Here is a link to the PowerPoint slides of my hederelloid talk. If you just have to know more, here’s a 2008 Taylor and Wilson hederelloid paper as a pdf.
I very much enjoyed talking with members of this club. They love fossils for their beauty, complexity, and historical wonder. To be able to contribute to science is a bonus.
Mark Wilson August 11th, 2010
OPPENHEIM, GERMANY–Our International Bryozoology Association field trip started the day in the little town of Prüm looking at Devonian limestones and shales, and then we drove to Boppard where we boarded a Rhine River ferry for a trip upstream to Bacharach. The weather threatened rain but held off, giving us excellent views of the steep sides of the middle Rhine Valley with its little villages, precipitous vineyards, and numerous castles.
One of the attractions of this voyage was the “Loreley“, a large cliff at the narrowest point of the Rhine. It has historically been the site of many accidents because of the shallow, fast waters over the rocky river bed near the outcrop. There is a thick crust of Germanic sentimentality over this place which I don’t quite understand. In our case it involved the ferry loudspeakers playing a song based on a poem by Heinrich Heine that is a traditional favorite. At least I know this: the rock is a Lower Devonian quartzite, part of the Taunus Formation, and derived from tidal flat sediments!
The Loreley exposure on the right bank of the Rhine River, Germany.