189-13 Extracting 3D Morphometric Data from Submerged Tracks in Glen Rose Formation (Albian, Early Cretaceous), Blanco, Texas

Session: Paleontology, Paleoecology/Taphonomy (Posters)

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Abstract:

In Central Texas, the Glen Rose Formation (Albian, Early Cretaceous) features numerous tracks and trackways of sauropod, theropod, and ornithopod dinosaurs, often exposed along riverbeds and creeks. Originally, Pittman (1992) documented at least 17 large sauropod trackways along the Blanco River in Blanco, Texas. Two such trackways are located 40 meters downstream of the river crossing and remain underwater many months of the year, making it challenging to measure and document these submerged tracks. In 2020, the site was visited as part of a larger, ongoing project aimed at documenting Central Texas dinosaur tracksites. Despite those tracks remaining underwater, digital data were collected for photogrammetry. In 2023, ground-based measurements were collected on 39 tracks exposed due to several months of drought. Using Agisoft Metashape software, photographic data from approximately 1,600 UAV-captured images were processed to construct robust 3D models of several dinosaur trackways to obtain descriptive measurements including foot length and width, stride, pace and gait of trackmakers. Statistical analysis of those data established how statistically different or similar digital measurements are to ground-based measurements collected on-site. Using the programming language R in RStudio, parametric tests found no statistical differences in linear measurements between the ground-based measurements and those captured from the digital model. However, depth measurements are excluded from this application. Furthermore, a strong positive correlation between ground-based and digital measurements suggests the model can be used to gather morphometric data on the remaining underwater tracks, thus providing quantitative data otherwise unavailable to the study. These results increase the documented track count and improve measurement precision, advancing earlier findings and enhancing analysis of trackmaker size, locomotion, and behavior at this site.

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

doi: 10.1130/abs/2025AM-11158

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