Mosaic Convergence of Rodent Dentitions
Figure 7
The five morpho-functional grades recognized in the present work in muroid left M1 along with their potential evolutionary relationships.
For each grade, a computed 3D rendering with superimposed colour topographic map is presented on the left. The colour code refers to the elevation while the grey-level code refers to the slope value. Scale bar: 500 µm. The topologic map presented on the right indicates the main cusp tip (crosses) or their flattened surface (grey areas), the outline of the four main cusps (dotted lines), the orientation of their lowest slope (black arrow) and the direction of chewing (grey arrow). A. Grade B: oblique masticatory movements and cusp interlocking associated with cuspidate crown, oblique cusp lowest slope and cricetine or intermediary dental plan. B. Grade C: oblique masticatory movements and non cusp interlocking associated with flattened crown, oblique cusp lowest slope and cricetine dental plan. C. Grade O: longitudinal masticatory movements and cusp interlocking associated with cuspidate crown, oblique cusp lowest slope, and cricetine plan. D. Grade M: longitudinal masticatory movements and cusp interlocking associated with cuspidate crown, longitudinal cusp lowest slope, and murine or intermediary dental plans. E. Grade D: longitudinal masticatory movements and non-cusp interlocking associated with flattened crown, longitudinal cusp lowest slope, and murine or cricetine dental plan. During muroid radiation, Grades C, O, and M emerged from grade B and independently gave rise to grade D. The example chosen to illustrate the grades are not phylogenetically related.