Evolution of the Heliornithidae: Reciprocal Illumination by Morphology, Biogeography and DNA Hybridization (Aves: Gruiformes)

Abstract

Abstract—Finfoots (Heliornithidae) were chosen to test the possibility that there has been a dramatic reversal in a suite of morphological characters, intimated by an earlier phylogenetic reconstruction of Gruiformes based on DNA hybridization. There are three nodes where unstudied finfoots could stem from the existing reconstruction. The resulting alternate trees have largely exclusive implications for morphological character suite polarity, biogeography and fossil identifications. A new DNA hybridization study that includes all relevant taxa was intended to form the basis for independent evaluation of the trees, but it produced results that conflict with the earlier DNA study. So, instead, DNA trees were evaluated by their reproducibility and consensus with most-parsimonious trees, biogeography, paleontology and traditional classifications, I concur with traditional classifications that finfoots are monophyletic, and that Limpkin (Gruiformes: Aramidae) is the sister of cranes (Gruiformes: Gruidae). Limpkin is not supported as the sister of the Sungrebe ( Heliornis fulica) or as a member of the Heliornithidae, as reported in the earlier DNA study. It is alarming that the gross lack of consensus with traditional characters and concomitant implications for character suite polarity in this case went unquestioned.