Venation pattern of Orthoptera

The revision of several taxa previously attributed to the plesion ‘Protorthoptera’ yielded information about the venation pattern of Orthoptera and the sister-group relationships of Orthoptera. A new wing venation pattern is proposed, i.e., (1) a basal composite stem M CuA, distally separated into M and CuA; (2) distal free CuA fused with the anterior branch of CuPa (CuPa ‘alpha’). We consider the clade Orthoptera as an apomorphy-based group (sensu Brochu & Sumrall), on the basis of this complex structure and, also by the presence of two branches of MA, MA1 and MA2 (but reversed in some recent taxa, having a MA simple). In the stem group of Orthoptera, the free part of CuA is fused with CuPa, i.e., CuPa is not ramified into CuPa ‘alpha’ and CuPa ‘beta’. Also, MA is simple.