Postdoctoral Fellowship: EAR-PF: Is there a taphonomic clock? Assessing the progression of terrestrial bone alterations across environments and time

Dr. Rachel Laker has been awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out research and professional development activities at the University of Cincinnati under the mentorship of Dr. Joshua Miller and at South Dakota School of Mines under the mentorship of Dr. Sarah Keenan. In this fellowship, Dr. Laker will investigate the accumulation and morphology of taphonomic damage (cracks, microbial tunnels, and other damage that occurs after death but before burial) on bones as related to the time of decay and loss of the organic collagen. Taphonomic damage on bones is often used to estimate how much time is represented by different bone and fossil accumulations, which is critical information when comparing faunas from different ages or localities. The rates at which taphonomic damage accumulates are largely unknown. Actualistic experiments are generally evaluated over limited amounts of time (weeks to perhaps decades) and frequently yield rates of destruction that conflict with observations from bones found on natural landscapes, which can persist from years to millennia. To better understand how taphonomic damage forms, and quantify the rates at which it occurs, Dr. Laker will measure the taphonomic damage accumulated on caribou antlers that have been decaying across several millennia (evaluated using radiocarbon dating). To increase science engagement and cultural connectivity, on a regular basis Dr. Laker will virtually engage with the Gwich’in Native Alaskan community bordering the Arctic National Wildlife Refuge. Dr. Laker will continue to serve the geosciences community as an advocate for belonging, accessibility, justice, equity, diversity, and inclusion values through undergraduate mentorship and professional service. This project aims to constrain our understanding of the physical manifestation and rates of taphonomic damage of bone on timescales ranging from years to millennia. Dr. Laker will (1) define the expression and variation of taphonomic alterations of a single environmental setting, including variability associated with collagen preservation and differences in bone construction, then (2) test the consistency of these findings, including the rates and morphologies of taphonomic alterations, across a latitudinal gradient. By integrating microscopic and macroscopic scales of analysis to improve our understanding of the formation of ubiquitous but poorly understood taphonomic features, this work will address shortcomings in taphonomic laboratory and field experiments to contribute to a more comprehensive understanding of the links between time and taphonomic degradation of bone. This research will generate a toolkit for assessing the time represented by faunal assemblages of different environments, enhancing paleoecological comparisons of paleontological records. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.