Ichnofossils provide a critically important in situ record of paleoenvironmental and paleoecological change that has become an essential aspect of sedimentology, stratigraphy, and paleontology. Data collected through experiments performed with modern marine organisms have revealed the behavioral and environmental factors that affect marine ichnofossil morphology and distribution. This proposal seeks funding to study the burrowing behavior and biogenic structures of extant terrestrial animals for application to the study of ichnofossils. By studying the behavior of continental tracemakers, the morphology of their burrows, nests, tracks, and other traces may be correlated to continental environmental factors such as temperature and precipitation, depositional environments, and such substrate characteristics as soil consistency, moisture level, and organic content. In addition, if trace morphology can be linked to specific taxa or body morphologies, then these traces may be used in lieu of body fossils to determine the geographic and temporal range of different groups of organisms. This study will evaluate two hypotheses concerning the connections between trace morphology, tracemakers, and environment: (1) continental ichnofossil morphology can be linked to specific taxa allowing ichnofossils to be used to determine the geographic and temporal range of ancient organisms; and (2) continental ichnofossil morphology varies in a predictable manner with changes in environment and climate. These morphological variations can provide such paleoenvironmental and paleoclimatic data as temperature, soil moisture, substrate consistency, and sedimentation rates. To test these hypotheses an integrated study will be employed that will include detailed laboratory studies of burrows, tracks, and trails produced by continental invertebrates and vertebrates as well as the analysis of changes in ichnofossil morphology due to changes in substrate consistency, soil moisture, and surface air temperature. Laboratory studies will involve the study of twenty six species of terrestrial annelids, arthropods, amphibians, and reptiles in large, substrate-filled terrariums in temperature-controlled rooms. The test animals will be exposed to variations in temperature, soil moisture, and substrate composition. Biogenic structures produced in the laboratory including subsurface burrows and chambers as well as surface tracks and trails will be photographed and cast for morphological analysis. This project will include the production of an online neoichnological database that will be invaluable to students and professionals in both academia and industry for the interpretation of ichnofossils and sedimentary facies. Using this database ichnofossils can be directly compared to modern traces to determine likely tracemakers, means of excavation, behavioral significance, and environmental conditions at the time of burrow construction. The online database will be accessible through the Ohio University Department of Geological Sciences website and will provide detailed descriptions, measurements, and photographs of modern traces. The primary contributions to training achieved by this grant will be training three graduate students and up to ten undergraduate students in laboratory techniques of specimen-based ichnology and paleontology as well as the presentation of results at scientific meetings and in scientific journals. This project will train graduate and undergraduate assistants in the skills necessary for future careers in geology or paleontology. In addition to students directly assisting in the project, students in introductory paleontology, paleoecology, and ichnology courses at Ohio University will use the animal laboratory to complete short laboratory projects as part of their regular course work. These projects will be designed to teach students how to formulate hypotheses, test hypotheses with experimental techniques, interpret results, and write scientific reports. Finally, many of the casts and reproductions of biogenic structures produced in this project will be used to create a museum exhibit for the Cincinnati Museum of Natural History and Science. This exhibit will be designed to educate the public on the interaction of animals and the soil environment as well as the role of ichnofossils in modern paleontology.
