David Treviño Ledesma Postdoctoral fellow at at the Natural History Museum of Los Angeles County, USA.

Can you tell us a bit about yourself and your research interests?

I’m originally from Richmond, Texas. My research interests lie at the union between paleontology, herpetology, and conservation biology. More specifically, I’m interested in using the fossil record as a study system for investigating the responses of herpetofauna (reptiles and amphibians) to environmental change. My research primarily focuses on the responses of herpetofauna to environmental change since the last glacial maximum (around 20,000 years ago) with the goal of disentangling how different environmental factors (e.g., climate, vegetation, human landscape management) have impacted populations and communities. My goal is to bridge the fossil record with modern data in order to provide insights that are directly relevant for identifying and addressing current and future conservation challenges.

What first interested you in this field of research?

I’ve always been interested in how the fossil record provides us with clues for reconstructing the past. Since the last glacial maximum there have been substantial environmental changes (e.g., climate, vegetation, and human land use and management) which got me interested in investigating the extent to which the fossil record allows us to deepen our understanding on how biota respond to these changes. I also have always had a fascination and admiration for herpetofauna and I wanted my work to provide knowledge that aids in conservation of modern species.

Can you briefly explain the research you presented at NAPC 2024?

The research I presented at NAPC was on changes in a central Texas lizard community in response to environmental changes over the last 16,000 years. Using fossils from a cave in Kerr County, Texas, I documented shifts in the lizard community composition through time. I integrated paleoenvironmental data, such as isotope ratios and pollen records from previous studies on this locality, to track how past changes in temperature, precipitation, and vegetation impacted these lizards.

How will you continue to build on this research?

My research revealed substantial changes in the lizard community due to environmental shifts in the region. Moving forward, I aim to study herpetofauna from additional fossil sites in Texas and other regions to gain a broader understanding of how taxa respond to different types of environmental changes. I plan to pair these findings with modern ecological studies to inform conservation strategies that protect today’s biodiversity.

 

Michael Chiappone PhD Candidate at the University of Minnesota, USA.

Can you tell us a bit about yourself and your research interests?

I am a PhD candidate working in vertebrate paleontology with a focus on fluvial taphonomy. I did my undergrad in geology at the Jackson School of Geosciences at UT Austin, where I developed an appreciation not just for fossils, but the rocks around them and the complex processes that lead the formation of fossil sites. When examining the transport and burial of bones in river environments via actualistic experimentation in flumes during a Masters project at the U of M showed intriguing results, I switched to PhD track to continue to build on that research. Using experimental flume data, I aim to develop new, quantitative taphonomic methods that can be used across the field of vertebrate paleontology to better constrain the histories of fossil sites and understand biases in the fossil record.

 

Mason Scher PhD Candidate at Princeton University, USA.

Can you tell us a bit about yourself and your research interests?

I’m interested in using stable isotope geochemistry to reconstruct environments, ecology, and climate of past terrestrial environments. I love the idea of adding layers of understanding to the fossil record with new methods or new archives. Most of my graduate school work has focused on enamel as an archive of paleoecological information, but I’m also very interested in fossil plants and using stable isotope systems to better understand modern plant functioning.

What first interested you in this field of research?

I had an amazing internship between my sophomore and junior years of undergrad at the Smithsonian NMNH in the Paleobiology department with Dr. Rich Barclay and Dr. Scott Wing. I saw that my interests in chemistry could be applied to understanding the natural world in the fossil record through isotope geochemistry, and I was hooked!

Can you briefly explain the research you presented at NAPC 2024?

At NAPC, I presented ongoing work measuring the nitrogen isotopic composition of organic material preserved within Celtis (common name Hackberry) seeds. Celtis is unique in producing a calcium carbonate shell (the endocarp) around the seed which is all wrapped up in a fleshy fruit. The calcium carbonate portion of the fruit has is found in the fossil record over the last ~ 60 Ma, and it preserves tiny amounts (nanomole quantities) of organic material within the endocarp biomineral. We found a correlation between the nitrogen isotopic composition of this organic matter and precipitation that we plan to further develop as a paleo-precipitation proxy.

How will you continue to build on this research?

We’ll continue to add to the modern calibration of Celtis biomineral-bound nitrogen isotopic composition. Today, there are numerous species of Celtis that grow in different habitats and precipitation regimes. Herbarium collections contain samples of Celtis from around the world and are a great way to collect a wide array of samples. After characterizing the modern relationship between nitrogen isotopic composition and precipitation, it will be time to apply this method to fossil endocarps!