Thursday, Feb 22, 2018
AIPG Ohio 2018 Winter Meeting
Location: The Nutter Center, Berry Room, Wright State University (https://www.nuttercenter.com/rental-spaces/berry-room)
3640 Colonel Glenn Highway, Dayton, Ohio 45435 (map)
Social Hour: begins at 5:00 pm
Dinner: 6:00 pm
Feature Presentations: 7:00 pm
Dinner will be buffet-style with cash bar. Cost will be $25 for adults and $10 for students.
Registration for this event is now closed.
There will be two feature presentations, including:
- Ectocochleate Cephalopod Hydrostatics: 3D Reconstruction and Computation of Life Orientation and Static Stability during a Neutrally Buoyant Condition
- Speaker: David Peterman, Graduate Student, Department of Earth and Environmental Sciences, Wright State University, and
- Marine Vertebrate Ecology during the Early Permian
- Speaker: Ryan Shell, Graduate Student, Department of Earth and Environmental Sciences, Wright State University, Dayton, Ohio
David Peterman Bio: David Peterman is a 2nd year PhD student at Wright State University. His research interests include the functional morphology of fossil cephalopod shells (nautiloids and ammonoids). He's recently developed a new method to compute the requirements for neutral buoyancy, syn vivo static orientation, and hydrostatic stability. This involves generating 3D models from digitally reconstructed fossil cephalopod shells. The hydrostatic properties of externally shelled cephalopods have implications for better understanding how these enigmatic organisms functioned in their ecosystems, biodiversified, and became major components of Paleozoic and Mesozoic oceans.
- Presentation Abstract: During the Early Ordovician, diversification of nautiloid cephalopods led to an increased occupation of the pelagic zone. The early cephalopods of the Upper Cambrian (the order Ellesmerocerida) almost exclusively inhabited the neritic zone. New orders of nautiloids appeared during the earliest Ordovician including the Endocerida, Orthocerida, among many others, which rapidly diversified. Understanding the hydrostatic properties of morphotypes that best represent these orders is essential to better understand the diversification of nautiloid modes of life during their evolutionary history. This includes generating 3D models in order to compute the conditions for neutral buoyancy (when applicable), static orientation during life, and hydrostatic stability. The ellesmerocerid model was found to be negatively buoyant, which supports the interpretation of this morphotype being restricted to the benthos in a neritic habitat. The Endocerid and Orthocerid models were capable of neutral buoyancy due to the proportions of the living chamber (which was occupied by the soft body of the living nautiloid), and the phragmocone (the chambered portion of the shell used as a buoyancy apparatus). Both of these morphotypes were very stable in a vertical orientation, suggesting they would have been able to serve as pelagic vertical migrants. The distribution of liquid in the phragmocone and mineralized deposits employed by many families within these orders may have been modifications to actually reduce stability to allow deviation from the stable, vertical lifestyle.
Ryan Shell Bio: Ryan Shell is also a 2nd year Ph.D. Student at Wright State University. His primary research interest is in the ecology of ancient sharks. During the course of his research at WSU, he discovered a fossilized ecosystem in north central Texas that appears to behave much differently than the original understanding of marine vertebrate ecosystems from the same age. This means that the understanding of how sharks and ocean fishes lived an evolved alongside one another is much more complex than previously thought. This extra complexity may explain the rise of certain modern ocean species, and the interaction between the marine and terrestrial realm here may eventually provide clues into how land animals, such as the proto-mammals first appeared. Additionally he's published on dinosaur trackways from the Cretaceous, and he is currently conducting research in the Ice Age of western Ohio.
- Presentation Abstract: The early Permian Period was a hugely significant time in the history of life on Earth. Between 288.9 and 272.3 million years ago tetrapods, which first appeared 100 million years previously, began to form the first truly terrestrial communities- with fewer inputs from the marine realm, compared to previous communities in the Carboniferous or Devonian Periods. While connections between oceanic and terrestrial ecosystems lessened during this time, the fact remains that the two are connected today, and that changes in one system may impact the other. The marine vertebrate ecosystems from this time are thought to be composed of bony fishes and sharks adapted to feed directly on the animals of a typical Paleozoic reef. Bony fishes were, in turn, supposedly preyed upon by small sharks who themselves were eaten, along with the grazing sharks, by large bodied Eugenodonts (Helicoprion for example). Fossils in the Lueders Formation of north-central Texas present a somewhat different composition, and in comparing this fauna to those of Bolivia and Russia, we can describe more certainly the global marine vertebrate ecosystem from this time. Furthermore, some sharks adapted to both graze on shellfish and prey upon fishes in Texas were able to move regularly between nearshore and farshore marine ecosystems; providing, a framework to understand the flow of nutrients between vertebrates across the marine/terrestrial divide. We now have a better understanding of how these marine vertebrate communities worked, and how they may have interacted with terrestrial ecosystems during this period.