Complexity of septal surfaces and suture lines in ammonoids - implications for the hydrostatic apparatus and palaeoecology using modern CT-techniques
In the course of the 350 million years (Lower Devonian-Upper Cretaceous) of ammonoid evolution, the iterative trend of development starting with simple to complexly, folded septa of the phragmocone is well documented. Changes in the ratio of chamber volume against the inner chamber surface allow statements about different lifestyles in different ontogenetic stages and comparisons between different taxa.
Denoising microtomography for automated segmentation of fossil ammonites
Recent enhancements in tomographic imaging techniques enable a non-invasive view inside fossil structures with astonishing spatial resolution. However, a manual segmentation to reconstruct the structure of fossil ammonites from tomographic data is very labor intensive and time consuming, requiring several weeks for one ammonoid specimen. In case the signal to noise ratio (SNR) is low or imaging artifacts occur, an automatic reconstruction process turns out to be too difficult to derive useful information from the tomography data using current techniques.
Our first aim is therefore to develop specialized algorithms for image denoising. We are implementing a multi-level approach which runs on highly parallelized hardware such as graphic boards (GPU). Further, a concept will be developed which allows fast, automated segmentation of CT-data and a subsequent morphological analysis – not only in cross-section but also showing three-dimensional developmental patterns during ontogeny.
06/2012 – 05/2015
Hoffmann, R. & Zachow, S. (2011): Non-invasive approach to shed new light on the buoyancy business of chambered cephalopods (Mollusca). Extended Abstract IAMG Salzburg 2011, 2011: 1-9.