The Southeastern GSA meeting wrapped up today with a full slate of talks and posters. I spent a little more time in talks today, including several in a Paleontological Society symposium in honor of Richard Bambach.
Bret Bennington and Myla Aronson presented on the advantages and difficulties in using paleontological data in ecological research. Incorporating fossil data into studies can provide an ecological baseline for what a community was like before human disturbance, as well as demonstrate how a community can change over longer periods of time. However, the difference in time scales and sampling techniques between paleontological and biological data can be problematic.
Brooke Haiar attempted to compare dinosaur diversity between the Late Jurassic Morrison Formation and the overlying Early Cretaceous units such as the Cloverly Formation. The types of dinosaurs are quite different between these units, with sauropods common in the Morrison while ornithischians such as Tenontosaurus (above, from the Sam Noble Museum) dominate in the Cretaceous. There appears to be a lower diversity of dinosaurs in the Early Cretaceous, but it turns out that much of this may be due to sampling and reporting biases.
After Brooke’s talk I rushed to another room in time to hear part of a talk by VMNH’s Sarah Timm and Jim Beard on collections record-keeping and EGEMS, the database used at VMNH to store data on our geological and paleontological collections. The next talk in the session was Christina Byrd (with Sarah and me as coauthors) describing our part of the Fossil Insect Collaborative, including some of the details of the workflow Christina developed to streamline the photography of the Solite insects.
The paleontology poster session was held in the afternoon. Robert Denton, Bob Weems, and Gary Grimsley presented on crocodilians from the Paleocene Aquia Formation in Maryland and Virginia, which appear to be more diverse than previously thought, with representatives from several families.
There were four posters from groups of students working in Christy Visaggi’s lab at Georgia Southern University, all concerning different aspects of the molluscan fauna in the Pleistocene Waccamaw Formation of North Carolina. The fauna is quite diverse (i.e. lots of species), but only 8-10 genera are responsible for 75-80% of the individual shells. Almost all the bivalves were suspension feeders, but a large percentage of the snails were predatory.
James Kerr and Patricia Kelley examined predation scars on ammonoid cephalopod shells. Their data indicate that heavily ornamented shells (such as Collignoniceras, below, from South Dakota School of Mines) have fewer predation scars, suggesting that the ornamentation may serve as a kind of anti-predator armor.
Michael Meyer and Aaron Howard reported on new collections in Virginia of a relatively poorly understood trilobite, Ampyxina powelli (below, from the VMNH collections). This tiny trilobite is rare and known from only a few localities.
I wrapped up my day with trace fossils, attending a very entertaining talk by Tony Martin (@Ichnologist on Twitter) about a walking fish trace fossil from the Pennsylvanian of Alabama. This may have been made by something behaving in a similar way to a modern mudskipper such as the one below (from the National Aquarium), pulling itself across the mud with its fins. Tony demonstrated the behavior for us, and his imitation of a walking fish has to be seen to be believed!