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To better understand the biology of extinct animals, experimentation with extant animals and innovative numerical approaches have grown in recent years. This research project uses principles of soil mechanics and a neoichnological field experiment with an African elephant to derive a novel concept for calculating the mass (i.e., the weight) of an animal from its footprints. We used the elephant's footprint geometry (i.e., vertical displacements, diameter) in combination with soil mechanical analyses (i.e., soil classification, soil parameter determination in the laboratory, Finite Element Analysis (FEA) and gait analysis) for the back analysis of the elephant's weight from a single footprint. In doing so we validated the first component of a methodology for calculating the weight of extinct dinosaurs. The field experiment was conducted under known boundary conditions at the Zoological Gardens Wuppertal with a female African elephant. The weight of the elephant was measured and the walking area was prepared with sediment in advance. Then the elephant was walked across the test area, leaving a trackway behind. Footprint geometry was obtained by laser scanning. To estimate the dynamic component involved in footprint formation, the velocity the foot reaches when touching the subsoil was determined by the Digital Image Correlation (DIC) technique. Soil parameters were identified by performing experiments on the soil in the laboratory. FEA was then used for the backcalculation of the elephant's weight. With this study, we demonstrate the adaptability of using footprint geometry in combination with theoretical considerations of loading of the subsoil during a walk and soil mechanical methods for prediction of trackmakers weight.

It is commonly assumed that reactions in the silicification of land plants take place at low to moderate diagenetic temperatures when the solvent for the silica (H2O) is in the liquid stability field. The early Permian forest of Chemnitz, buried by rhyolitic pyroclastic deposits ca. 290 Ma, may be an example of silicification at elevated temperatures above 100 °C by siliceous H2O vapor. Many independent observations support this theory: the presence of low-density (gaseous) inclusions in primary α-quartz, the impregnation and partial replacement of silica phases in the wood by fluorspar, the preservation of relict organic material in the form of the high-temperature mineral anthracite, and the close proximity of the fossil forest to an eruptive center, the Zeisigwald Caldera. We have designed an experimental apparatus that allows silicification to be simulated by silica-bearing H2O vapor. Water was reacted with rhyolitic obsidian at 150 °C for several days to take up silica, then passed through the parenchymatous stem tissue of Dicksonia antarctica in the form of a hot, silica-bearing steam. The reactions taking place in the organic tissue are documented. Amorphous silica gel was found deposited in vapor-treated cells, suggesting that steam can be efficient in transporting aqueous silica species and depositing them into stem tissue. These experiments cannot duplicate every detail found in the natural examples in Chemnitz, but they do underline how important it is to derive the temperature conditions at which the natural silicification reactions took place.

To better understand the biology of extinct animals, experimentation with extant animals and innovative numerical approaches have grown in recent years. This research project uses principles of soil mechanics and a neoichnological field experiment with an African elephant to derive a novel concept for calculating the mass (i.e., the weight) of an animal from its footprints. We used the elephant's footprint geometry (i.e., vertical displacements, diameter) in combination with soil mechanical analyses (i.e., soil classification, soil parameter determination in the laboratory, Finite Element Analysis (FEA) and gait analysis) for the back analysis of the elephant's weight from a single footprint. In doing so we validated the first component of a methodology for calculating the weight of extinct dinosaurs. The field experiment was conducted under known boundary conditions at the Zoological Gardens Wuppertal with a female African elephant. The weight of the elephant was measured and the walking area was prepared with sediment in advance. Then the elephant was walked across the test area, leaving a trackway behind. Footprint geometry was obtained by laser scanning. To estimate the dynamic component involved in footprint formation, the velocity the foot reaches when touching the subsoil was determined by the Digital Image Correlation (DIC) technique. Soil parameters were identified by performing experiments on the soil in the laboratory. FEA was then used for the backcalculation of the elephant's weight. With this study, we demonstrate the adaptability of using footprint geometry in combination with theoretical considerations of loading of the subsoil during a walk and soil mechanical methods for prediction of trackmakers weight.