These anatomical models included bone surfaces, implant surfaces, and anatomical landmarks, which were used to quantify the bony geometry and to consistently define local coordinate systems for describing segment as well as 3-dimensional (3-D) implant positions and orientations.
Because the intersections between wing veins provide landmarks that can be located precisely, shape variation is easy to quantify with the landmark-based methods of geometric morphometrics [ 35] and the Drosophila wing has therefore been widely used for morphometric studies [ 36- 40].
Although recent studies on morphological shapes have applied this statistical analysis to evaluate the correlated units between two sets of several landmarks [ 80, 91, 92], this study used this coefficient to quantify the correlation between two landmarks in every possible combination.
Traditional and landmark-based geometric morphometrics methods were used to quantify variation in body size, body shape, and armor.
Landmarks (LMs) manually placed by two observers allow to quantify the local accuracy and precision of DIR, while including the intraobserver error [ 25].
The GPS generated a consensus configuration for both mandibles and a thin-plate spline was used to quantify deviation of individual specimen landmark configurations from the consensus along principal axes of shape change [ 40, 41].
The standard is the "gunsight" CT scan or MRI, employing accepted bony landmarks to define and quantify the degree of malrotation of the femur and/or tibia.
Fifteen landmarks were digitized on each image using tpsDig v2.16 (Rohlf 2010) to quantify shape differences between individuals.
To quantify shape variation among individuals, we conducted landmark-based geometric morphometric analyses (GM; [33], [34]).
To quantify variation in body shape, we used a morphometric analysis of 13 landmarks along the left lateral side of the fish as described by Nichols et al. (2008) and Varian and Nichols (2010).
