Figure 29. The mean orientation of u₁ in the medial femoral condyle, referenced in the femur anatomical coordinate system.

This is plotted on an equal-angle stereoplot, with southern hemisphere projection (using StereoNet 9.5). (A) The results for all specimens analysed; for clarity, only the posteromedial quadrant of the plot is shown. Note that for the fossil specimens, only those that were complete and well-preserved, and enabled an anatomical coordinate system to be defined, were analysed. Colour codes: black = birds, pink = human, blue = Masiakasaurus (FMNH PR 2153, UA 8384), orange = Falcarius, green = Troodontidae sp., purple = general orientation for Allosaurus and the tyrannosaurids, yellow = indeterminate ornithomimid (TMP 91.36.569), brown = indeterminate caenagnathid, red = mean orientation across birds. (B) Comparison of posterior inclination of u₁ in sagittal plane versus femur length in birds, with major axis regression line (and associated statistics) plotted.