Comparative Morphometrics

Using both 2D and 3D geometric morphometric approaches, I am describing morphological diversity, identifying ecomorphological modes, and comparing evolutionary allometry and integration in ground squirrels and other mammals.

Ecomorphology and Multi-level Allometry in Marmotini

This project compares the tempo and mode of evolution in multiple cranial traits (crania, mandibles, molariform teeth). It is also focused on assessing the extent of morphological convergence in these traits.

Results of principal components analysis and canonical variates analysis of 3D cranial shape in 12 genera of Marmotini (plus Sciurotamias), showing separation of putative ecomorphologies in morphospace. The genera are abbreviated with 2-letter codes at right; allometric variation has been removed.

Ontogenetic shape changes in the crania of 3 different ground squirrel genera (putative grazing ecomorphs), visualized as wireframe graphs (gray=smallest individuals, black=largest individuals, dots=3D landmarks). These shape change trajectories are statistically indistinguishable.