Mantophasmatodea: a new insect order?

Klass et al. (1) linked the extinct fossil taxon Raptophasma to newly described species of an extant taxon Mantophasma, hypothesizing that they form a monophyletic group. This result is interesting and uncontroversial. However, I doubt the claim that Raptophasma and Mantophasma represent a new order of Insecta, Mantophasmatodea. I feel that these insects are instead aberrant members of the order Orthoptera, which also includes Ensifera (crickets and katydids) and Caelifera (grasshoppers). Klass et al. stated that “[a]lthough wingless and nonjumping Orthoptera . . . can be modified almost beyond recognition, the large prothoracic pleuron unconcealed by pronotal lobes and the lack of an anterior intervalvula in the ovipositor exclude Mantophasma from this clade.” However, presence of a fully formed pleuron does not exclude Mantophasma from the order Orthoptera, because this condition is found in at least one family (Proscopiidae) within Orthoptera (2). Furthermore, the presence of anterior intervalvula has never been demonstrated to be a synapomorphy of Orthoptera (some Phasmida, such as Timema, also possess it). Even if the absence of the structure were an autapomorphy, it would not exlcude Mantophasma from Orthoptera. Similar arguments apply to the “lack of longitudinal series of denticles in the proventricule” cited by Klass et al. (1). Klass et al. also stated that having five tarsomeres is incompatible with Mantophasma being subordinate in the crowngroup Orthoptera. However, the first three tarsomeres of Mantophasma are synsclerotic, making the tarsi identical to those of the Caelifera family of Orthoptera (3). If Klass et al. had presented a cladistic analysis that included Mantophasma, showing that it is not phylogenetically subordinate to an already recognized major monophyletic lineage, it would be a sound basis for these authors to pose the hypothesis that Mantophasma and Raptophasma are a new order of Insecta. As it appears, support for their hypothesis is in the form of subjective opinions about morphological character polarity, and standard methods of phylogenetic analysis (i.e., simultaneous, unconstrained parsimony analysis performed using a published data matrix) were not used. Erich Tilgner Fernback Science Center 156 Heaton Park Drive Atlanta, GA 30307, USA E-mail: [email protected]