Three Dimensional Dinosaur Trackway Analysis
The Complexities of Dinosaur Tracks
A dinosaur track preserved and exposed is not always a true representation of the track maker s foot. This has been a common misconception within palaeontology for over a hundred years, and only recently has work highlighted the importance of transmitted tracks. These transmitted tracks are formed when sedimentary layers are deformed beneath the surface on which the dinosaur walked. The mechanical properties of the sediment, the foot morphology, and the limb kinematics affect the way pressures are distributed through the substrate. Depending on which layer within the substrate is exposed, the visible track may be a transmitted track, and thus vary considerably from the original surface track. Interpretation is dependant upon track geometry, so if a feature is incorrectly interpreted as a surface feature, subsequent analysis (speed, population dynamics etc) will be flawed.
Understanding Track Formation using Finite Element Analysis (FEA)
FEA is a numerical technique that is frequently used in engineering to evaluate the response of materials and mechanical designs to external factors. In this case, the material is the soil, and the external factor is the dinosaur s foot applying a load. By providing the properties of a given soil, and applying a load in a way consistent with modern research into dinosaur limb biomechanics (research that is also being undertaken at the University of Manchester), the FE model can provide us with a theoretical three dimensional soil volume realistically stressed according to the loading of the foot. Applying the failure criteria for the soil allows us to visualise the transmitted tracks at any position or section within the soil volume. This in turn facilitates the geometric and morphometric measuring of tracks and undertracks, ultimately providing a better understanding of dinosaur track formation, how closely fossil tracks resemble the track-maker s foot, and thus more confident interpretations.
- Dr Philip Manning
- Dr Lee Margetts
- Dr Emma Finch
- Dr Joanna Leng
- Mr Peter Falkingham