Judith River Formation reference section, Upper Missouri River Breaks National Monument (J. Thole photo)
RESEARCH ON SEDIMENTARY RECORDS: MADAGASCAR AND MONTANA
I am a sedimentary geologist and paleontologist who is most content when studying rock records that preserve abundant vertebrate fossils. I focus on the reconstruction of terrestrial depositional environments, and I am very interested in deciphering how alluvial systems evolve and respond to changes in accommodation. I apply sequence stratigraphic methods in terrestrial successions (when feasible), and I use significant stratigraphic surfaces (e.g., unconformities, flooding surfaces) in alluvial and shallow marine records to correlate strata and contextualize fossil occurrences (an example can be found here). I am particularly interested in conditions that lead to exceptional fossil preservation (look here for an example). On occasion I delve into lithostratigraphy and formalize new units, and a couple recent papers that relate to this effort can be found here and here.
Over the years I have worked with several exceptional Macalester students on projects relating to fossils and sedimentary geology. More information on these students and their various projects can be found on the PEOPLE page.
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Majungasaurus from MAD05-42 bonebed (R. Rogers photo)
TAPHONOMIC RESEARCH: MOSTLY VERTEBRATES, BUT IT'S ALL GOOD.
Taphonomic puzzles never fail to intrigue me. Over the years most of my taphonomic work has focused on terrestrial vertebrates (dinosaurs primarily), and my first published paper treated the taphonomy of three dinosaur bonebeds in the Two Medicine Formation of Montana (find it here). Since then, I have expanded my taphonomic studies to include fossil occurrences in Argentina, Zimbabwe, Madagascar, and Minnesota. I have even spent some time exploring the geochemistry of fossilization in the lab (find it here and here) and the preservation potential of marine invertebrates using the PBDB (find it here). That said, I tend to focus my efforts on concentrations of vertebrate fossils (BONEBEDS), and my recent work examines how vertebrate microfossil bonebeds (also known as microsites, vertebrate microfossil assemblages) form and how they express potential bias (find an example here).
Over the years I have worked with several exceptional Macalester students on taphonomic projects. More information on these students and their projects can be found on the PEOPLE page.
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Taphonomic puzzles never fail to intrigue me. Over the years most of my taphonomic work has focused on terrestrial vertebrates (dinosaurs primarily), and my first published paper treated the taphonomy of three dinosaur bonebeds in the Two Medicine Formation of Montana (find it here). Since then, I have expanded my taphonomic studies to include fossil occurrences in Argentina, Zimbabwe, Madagascar, and Minnesota. I have even spent some time exploring the geochemistry of fossilization in the lab (find it here and here) and the preservation potential of marine invertebrates using the PBDB (find it here). That said, I tend to focus my efforts on concentrations of vertebrate fossils (BONEBEDS), and my recent work examines how vertebrate microfossil bonebeds (also known as microsites, vertebrate microfossil assemblages) form and how they express potential bias (find an example here).
Over the years I have worked with several exceptional Macalester students on taphonomic projects. More information on these students and their projects can be found on the PEOPLE page.
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CURRENT PROJECTS
Mahajanga Basin Project (MBP)
This year marks the 20th anniversary of my role as geologist/taphonomist for the MBP, which has been funded continuously by the National Science Foundation since 1993. We (Kristi and me here at Macalester) collaborate with our co-PIs on the project (D. Krause, P. O'Connor, A. Turner, J. Sertich) to discover and interpret the amazing fossil and rock records of Cretaceous Madagascar. Numerous manuscripts related to this project can be found on my Publications page. Funding provided by NSF (EAR-1528273).
Montana Campanian Campaign
I began working in the Campanian record of Montana in 1987 during my masters thesis at the University of Montana, and I never left. I focus on the rocks and fossils of the Two Medicine and Judith River formations, although I have recently begun to explore the taphonomy of the Hell Creek Formation, with plans to compare fossil preservation among these three classic units of the Western Interior. My work out in Montana has been facilitated by many people and organizations, including Jack Horner (MOR), Greg Wilson (UW), my friends and colleagues at the BLM, the Blackfeet Tribe, and the people of the wonderful little hamlet of Winifred, Montana. Numerous manuscripts related to this work can be found on my Publications page. Funding provided by NSF (EAR-1052673) and BLM (L10AC16281).
CA-TIMS U-Pb Geochronology of the Campanian Western Interior
I am collaborating with Sam Bowring, Jahan Ramezani, Eric Roberts, and Dave Eberth on a new project designed to calibrate the "Zenith of Dinosaur Diversity" in the Western Interior. Using CA-TIMS U-Pb geochronology at the MIT Radiogenic Isotope Lab, we are targeting bentonites in the Campanian record from Alberta to Utah. We already have a few (4) new high precision ages in the Two Medicine and Judith River formations, and there are more to come. Once the dating is complete, we will be able to address a variety of questions that relate to the evolution of the basin and the animals within. Funding provided by NSF (EAR-1434892). My most recent publication relating to this work can be found HERE and HERE (rogers_et_al._2024_tmf.pdf)
ANCIENT PARASITES REVEALED: Pushing Trematode - Bivalve Interactions Upstream and Back to the Cretaceous
I recently collaborated with a few colleagues on a cool project that focuses on unique shell malformations shaped like perfect little igloos. The igloos represent a clam's reaction to infection by trematode larvae. The paper describing the occurrence was recently published in GEOLOGY (paper here).
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COPYRIGHT NOTICE: Reprints of published articles provided as a service to enhance accessibility and the exchange of information. In downloading, you agree to comply with United States copyright law (Title 17, United States Code) such that the reprints are not to be “used for any purpose other than private study, scholarship, or research.” All copyrights remain with the original publishers of the articles. Please make only a single copy of any article, for personal use only.
This year marks the 20th anniversary of my role as geologist/taphonomist for the MBP, which has been funded continuously by the National Science Foundation since 1993. We (Kristi and me here at Macalester) collaborate with our co-PIs on the project (D. Krause, P. O'Connor, A. Turner, J. Sertich) to discover and interpret the amazing fossil and rock records of Cretaceous Madagascar. Numerous manuscripts related to this project can be found on my Publications page. Funding provided by NSF (EAR-1528273).
Montana Campanian Campaign
I began working in the Campanian record of Montana in 1987 during my masters thesis at the University of Montana, and I never left. I focus on the rocks and fossils of the Two Medicine and Judith River formations, although I have recently begun to explore the taphonomy of the Hell Creek Formation, with plans to compare fossil preservation among these three classic units of the Western Interior. My work out in Montana has been facilitated by many people and organizations, including Jack Horner (MOR), Greg Wilson (UW), my friends and colleagues at the BLM, the Blackfeet Tribe, and the people of the wonderful little hamlet of Winifred, Montana. Numerous manuscripts related to this work can be found on my Publications page. Funding provided by NSF (EAR-1052673) and BLM (L10AC16281).
CA-TIMS U-Pb Geochronology of the Campanian Western Interior
I am collaborating with Sam Bowring, Jahan Ramezani, Eric Roberts, and Dave Eberth on a new project designed to calibrate the "Zenith of Dinosaur Diversity" in the Western Interior. Using CA-TIMS U-Pb geochronology at the MIT Radiogenic Isotope Lab, we are targeting bentonites in the Campanian record from Alberta to Utah. We already have a few (4) new high precision ages in the Two Medicine and Judith River formations, and there are more to come. Once the dating is complete, we will be able to address a variety of questions that relate to the evolution of the basin and the animals within. Funding provided by NSF (EAR-1434892). My most recent publication relating to this work can be found HERE and HERE (rogers_et_al._2024_tmf.pdf)
ANCIENT PARASITES REVEALED: Pushing Trematode - Bivalve Interactions Upstream and Back to the Cretaceous
I recently collaborated with a few colleagues on a cool project that focuses on unique shell malformations shaped like perfect little igloos. The igloos represent a clam's reaction to infection by trematode larvae. The paper describing the occurrence was recently published in GEOLOGY (paper here).
***************************************************************************************
COPYRIGHT NOTICE: Reprints of published articles provided as a service to enhance accessibility and the exchange of information. In downloading, you agree to comply with United States copyright law (Title 17, United States Code) such that the reprints are not to be “used for any purpose other than private study, scholarship, or research.” All copyrights remain with the original publishers of the articles. Please make only a single copy of any article, for personal use only.
