Geometric morphometries and the analysis of higher taxa: a case study based on the metendosternite of the Scarabaeoidea (Coleoptera)

A geometric morphometric analysis of families belonging to the Scarabaeoidea, using landmarks from three two-dimensional views (frontal, dorsal and lateral) of an internally situated rigid structure, the metendosternite, was carried out. Procrustes distances matrices were obtained to produce phenograms from the three analyses. Relative warp analyses were also performed and the first two relative warps for the three data sets plotted against each other. The metendosternite is an internally situated anatomical structure that has largely been neglected in past studies. However, it proved to be useful in geometric morphometric studies, because it is rigid and landmarks can be easily identified. Geometric morphometries is shown to be a powerful tool to identify phenetic relationships between higher level taxa, and the metendosternite is a new structure available for beetle systematisists.