Landmarking and sliding
Each 3D model was landmarked in Viewbox version 4.0 (dHAL software, Kifissia, Greece; http://www.dhal.com; Polychronis et al., 2013). One operator (first author)manually placed the fixed landmarks and curves. Curve semilandmarks were placed equidistantly and then were allowed to slide along their respective curves. Surface semilandmarks were placed following a thin-plate spline interpolation between the template and each specimen, followed by a projection to the surface of the 3D-model and the sliding procedure. Sliding was performed by minimizing the bending energy.