26-8 Experimentally determining the forces and sedimentary environments involved in miring crocodilians.

Session: Interdisciplinary Paleontology: New approaches to solving complex paleontological problems (Posters)

Presenting Author:

Authors:

Abstract:

Across the fields of vertebrate paleontology and taphonomy, the process of miring has been inferred as the cause of demise (or at least interment) of many fossil organisms. Current literature does not expand upon exactly how an organism becomes trapped in sediment, or how much force is required to free them. Analyses of fossil trackways and modern biomechanical studies often neglect to mention how the cohesive and adhesive properties of sediment are able to create enough suction force to trap organisms. In the modern-day Pilcomayo Megafan system in Paraguay, the yacare caiman, Caiman yacare, frequently becomes mired during the dry season when moving from drying areas towards less ephemeral bodies of water. Should the caiman be unable to free themselves, they die and have a chance of becoming buried in the next channel avulsion, providing them a better chance of becoming a future fossil on the fan.

Our research aims to use varying sizes of limbs from the related crocodilian, Alligator mississipiensis, to determine the forces involved in the miring prosses, and whether the forces required to free the limb are reasonable for a crocodilian of that size to produce. Using sediment of varying water saturations, including silt from the Rio Grande River system, pure sand, and pure bentonite clay, we will determine, though the use of a push-pull force gauge, which conditions are most likely to mire a crocodilian and how much force it takes to both sink and free each limb. We will then be able to predict the extent to which a healthy yacare caiman can free itself from a miring situation, what sedimentary environments are likely to be able to trap it, and what sized individuals are at risk of becoming mired at all. By acquiring these empirical data, we hope to gain greater insight into the miring of organisms of the distant past, allowing for more nuanced interpretation of potentially mired fossils and, potentially, the inference of additional ecological information from those specimens

Geological Society of America Abstracts with Programs. Vol. 58, No. 4, 2026

doi: 10.1130/abs/2026RM-14791

© Copyright 2026 The Geological Society of America (GSA), all rights reserved.