There has been a legitimate question as to whether it is possible to use morphological data to recover the patterns of evolution in a group as old and structurally diverse as coleoptera. The authors come to the reasonable conclusion that morphological data does have the power to resolve much of the phylogeny of coleoptera. In particular recent branching events were recovered with high support. However, the large amount of homoplasy across the larger data set produced two troubling results. One was yet another hypothesis for the relationship between the four extant suborders (the authors remind us that brings the recent total to eight), and the second was a propensity for taxa that are widely accepted as having a sister group relationship to a larger clade showing up as part of a subclade with the most derived members of the larger clade. The authors ascribe this to homoplasy and discuss the difficulty in assigning ancestral state for many traits that simply can't be scored in outgroups (wing folding for instance is largely absent in the Coleoptera outgroups).
I think that the authors make an accurate prediction of the importance of their paper to the incorporation of fossil data. With existing phylogenies like Hunt's 2007 which is based on molecular data it is very difficult to place fossils and calibrate our trees. However with a robust morphological data set we should be able to much more precisely place fossils within the beetle tree of life. Being able to constrain our trees in this way will make the margin of error involved in other analyses that much smaller and more likely to uncover interesting patterns.
Finally the authors provide us with an amazing resources of great images of the characters chosen for their analysis. The authors state that these images will be available in Morphbank. This would be great since they will probably be available for use for “private, education, research or other non-commercial purposes for free, provided that the source and the copyright holder are cited” I was unable to locate the images on Morphbank by DOI, species names, Authors, etc but hopefully they will get submitted and become available.
Thumbnail view of a section of the PDF showing the abundant high quality figures
The authors end their paper with a promise of an integrated paper that will bring together all of the morphological and molecular data that has been collected within the guise of the BTOL project. I really look forward to that one!