106-20 Investigating the Diet of Hadrosaurian Dinosaurs from the Kaiparowits Formation Using Carbon Isotope Geochemistry

Session: 37th Annual Undergraduate Research Exhibition Sponsored by Sigma Gamma Epsilon (Posters)

Poster Booth No.: 106

Presenting Author:

Mackenzie Boyd

Authors:

Boyd, Mackenzie K¹, Fricke, Henry C.², Maccracken, S. Augusta³

(1) Colorado College, Colorado Springs, CO, USA, (2) Colorado College, Colorado Springs, CO, USA, (3) Denver Museum of Nature & Science, Denver, CO, USA,

Abstract:

The use of stable isotope geochemistry, and in particular carbon isotope ratios (δ¹³C), to study Mesozoic ecosystems is not as widespread as it is in the Cenozoic, but it is growing. One interesting result of this work to date is how much variability there can be in the δ¹³C of tooth enamel from a single herbivorous dinosaur, in this case hadrosaurids, despite their living in relatively close proximity and in fairly uniform wet, floodplain environments. This study aims to explain the range of δ¹³C by measuring δ¹³C of plant fossils from two localities in the Kaiparowits Formation, located in Southeastern Utah, and comparing them to δ¹³C of hadrosaurs from nearby areas. Results suggest that one population of hadrosaurs was eating a high proportion of understory and aquatic plants from a closed-canopy forest, plants with unusually high δ¹³C.  Another population of hadrosaurs was eating a high proportion of understory leaves from an open-canopy forest with δ¹³C typical of a wet, floodplain environment. In other words, the large range in d13C of tooth enamel observed for hadrosaurs can be explained by dietary partitioning of food resources by means of spatial separation. Future research will hopefully determine if these ecologically distinct populations of hadrosaurs represent different sub-taxa, age groups, etc.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-10161

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