Figure 7

Shape analysis and segmentation of a CT scan of the skull of the London specimen (BMNH 37001) of Archaeopteryx lithographica for a study of the brain and inner ear and its adaptation to flight⁵⁰. Specimen was scanned at UT Austin’s High-Resolution X-ray CT Facility at low and high X-ray energies (120 kV and 180 kV). The resulting matrix data size was \(1024 \times 1024 \times 650\) voxels and the voxel size was \(20 \times 20 \times 46\, \upmu {\mathrm{m}}\). (A) The original segmentation (Fig. 1b in⁵⁰) which took \({\sim }\,100\) h of manual segmentation. (Visualization using Mimics v7.3, https://www.materialise.com) (B) Automated SWD analysis. The SWD detects continuous distributions of similar intensity and quantitatively characterizes their shape. Subsequent to the SWD analysis, a segmentation algorithm extracts the skull. The total processing time to produce figure (B) was 7 min and required no user input.