étude ostéo-morphométrique des tortues marines de ... - Seaturtle.org

Figure 7. Projection of all the superimposed scapula coordinates on first and
second components axes using AFD on PCA coordinates and associated shape
on axis’s limits.
The AFD on PCA consensus (figure 7) allows discriminating correctly the different
specimens. Bootstrap gives 78 correctly assigned and 8 incorrectly assigned specimens. We
obtained the same triangular pattern than with PCA except that Ca belongs to the Cm group.
This means that with scapula it would be difficult to assign an unknown specimen to a Cm or
a Ca. This triangular disposition of the 3 groups on PC1 and PC2 means that both of them
participated together to discrimination. PC1 concerns (figure 7) the angle between the
acromial process and the scapular prong (landmarks: 5, 6, 7) : it is more concave in Lk that in
Cm and Ca. Landmarks 1 and 2 show important variances that give two different shape
patterns on coracoido-humeral epiphysis.
PC2 contrasts larger acromial process and scapular prong on their basis for Cm and Ca than
for Cc, principally due to the position of landmarks 4 and 6. In Cm and Ca, and also in most
of the Lk, the angle formed by landmarks 2, 3 an 4 is concave whereas it is convex for Cc.
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