A Cladistic and Biogeographic Analysis of the Aorinae Subfamily Nov.

Abstract

The new sub-family Aorinae is proposed for a group of genera in the family Aoridae, central to which is the triad Aora Krøyer, Lembos Bate, and Bemlos Shoemaker. A distinguishing feature of the new sub-family is the ornamentation, with channels and plates, of the surface of the mandibular molar. The structure of these ornamentations has been investigated using the S.E.M. Secondary sexual characters exhibited by the male gnathopod 1 have been widely used in the past as a basis for the classification of the Aoridae. In the present work, the structure of the male gnathopod 1 is considered to be a poor indicator of phylogenetic relationship and is therefore given low weighting. A synapomorphy scheme based in the main upon mouthpart (principally the mandible), and uropod 3 structure, is proposed for the Aorinae. Character state trends are reviewed and their polarization determined by outgroup method. Parallel evolution is considered to be common in Aorinae, and examples of such parallelism are reviewed. The biogeography of the three major ingroup clades revealed by the cladogram is discussed.