The identification of concerted convergence in insect heads corroborates Palaeoptera

The relationships of the three major clades of winged insects - Ephemeroptera, Odonata and Neoptera - are still unclear. Many morphologists favor a clade Metapterygota (Odonata+Neoptera), but Chiastomyaria (Ephemeroptera+Neoptera) or Palaeoptera (Ephemeroptera+Odonata) have also been supported in some older and more recent studies.

A possible explanation for the difficulties in resolving these relationships is concerted convergence - the convergent evolution of entire character complexes under the same or similar selective pressures.

In this study we analyse possible instances of this phenomenon in the context of head structures of Ephemeroptera, Odonata and Neoptera. We apply a recently introduced formal approach to detect the occurrence of concerted convergence.

We found that characters of the tentorium and mandibles in particular, but also some other head structures, have apparently not evolved independently, and thus can cause artefacts in tree reconstruction. Our subsequen...