X-ray Micro Computed Tomography Seminar and Workshop

Abstracts

Integrating microCT to improve research and pedagogy in Earth Sciences - Recording

Emily Cooperdock (Invited speaker)

Assistant Professor, Department of Earth, Environmental & Planetary Sciences

Brown University

Research in Earth sciences strives to understand the processes that shape the Earth in 3D; however, we are often limited to making observations in 2D. As educators in academia, one of our goals is to teach students to think of 3D processes that occur over deep time and expose them to cutting edge research techniques. In this talk, I will describe how we use the Rigaku CT Lab HX benchtop instrument to enhance research in the fields of geochronology, petrology, and structural geology by being able to make direct 3D observations of the materials we work with. I will also show how we developed a new curriculum for a required undergraduate course in mineralogy at USC that exposed students to hands-on research with microCT data.

Assessing trabecular bone architecture at the divergence of bird-line (Avemetatarsalia) and croc-line (Pseudosuchia) archosaurs to reveal cardiopulmonary evolution and soft tissue relationships. - Recording

Paul Byrne (Invited speaker)

Ph.D. Student, Dinosaur Institute

University of Southern California

Birds and crocodilians today have highly specialized cardiopulmonary systems that are fine-tuned for energetically costly flight and underwater sit-and-wait ambush hunting (respectively). However, similarities in embryonic development suggest a shared common origin for this paired system. Reconstructing cardiopulmonary anatomy in the last common ancestor of bird-line (Avemetatarsalia) and croc-line (Pseudosuchia) archosaurs to pinpoint when cardiopulmonary anatomy diverged has been challenging due to a lack of preserved soft tissue in the fossil record + insufficient computational techniques needed to visualize the bone/soft tissue interface. Postcranial skeletal pneumaticity (external foramina leading to hollow concavities within intertrabecular space) is hypothesized to have allowed for the lightning and strengthening of bone to aid in energetics and has been stated to be a reliable osteological correlate for pulmonary diverticula in avian and nonavian dinosaurs. However, this has led to a fallacious link assuming all pneumatic instances equate to the presence of the avian air sac system in the fossil record. Thus, it is unclear if variation within the trabecular architecture itself can reveal interaction with diverticula, or if this variation exists solely due to locomotor or behavioral modifications influencing bone structure. I hypothesize that, if specific trabecular architectural morphologies can be identified based on pulmonary diverticula interacting with bone, then trabecular morphology can be sorted into the following categories: a. interaction with diverticula, or b. locomotory style. When incorporating fossil taxa before and after the divergence point between Avemetatarsalia and Pseudosuchia, the cause of variation within trabecular bone architecture can be better resolved. These preliminary results suggest that fine-tuned microCT visualization methods can allow a better understanding of cardiopulmonary evolution in extinct organisms and can allow for a better understanding of the acquisition of the unique cardiopulmonary systems present today in birds and crocodilians.