189-14 Using Avian Neoichnology to Reconstruct Ancient Lacustrine Ecosystems of the Jurassic Moenave Formation in Southern Utah

Session: Paleontology, Paleoecology/Taphonomy (Posters)

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Abstract:

The St. George Dinosaur Discovery Site at Johnson Farm (SGDS) in southern Utah provides uncommon insight into an early Jurassic lake ecosystem filled with a variety of body and trace fossils including a remarkable array of dinosaur tracks that represent such different locomotion behaviors as walking, running, crouching, and swimming. Tracks are the product of the interaction between the locomotion behavior of an animal and a sedimentary substrate. Tracks are preserved in situ and can therefore offer more detailed information about ancient environments than body fossils alone. Tracks produced by different behaviors (e.g., walking, running, swimming) have unique quantifiable properties that may further enhance environmental interpretations. Current neoichnological experiments involving domestic chickens (Gallus gallus domesticus) and domestic turkeys (Meleagris gallopavo domesticus) are being used as modern analogs for track production under different substrate conditions. The focus of our neoichnological experiments is how the depth of standing water and substrate compaction affect track preservation. We hypothesize that there is a relationship between locomotion-induced sediment compaction, as measured by bulk density, and the degree to which the trackmaker’s body is buoyed by water. Sediment under swim tracks should exhibit lower bulk density, whereas the sediment below terrestrial walking tracks should have greater bulk density because more weight was applied during the creation of the tracks. Future field work at the SGDS will include the use of non-destructive LiDAR to create high precision, three-dimensional models of a sample of excavated swim track blocks. LiDAR has not been used previously at the SGDS and will be a more time efficient method than photogrammetry. Using LiDAR in conjunction with neoichnological experiments, we aim to reconstruct Moenave Formation paleoenvironment and substrate conditions in order to better understand the preservation of rare dinosaur swim tracks.

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

doi: 10.1130/abs/2025AM-6981

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