Alexarasniidae Gorochov

Gorochov, Andrej V., 2011, A new, enigmatic family for new genus and species of Polyneoptera from the Upper Permian of Russia, ZooKeys 130, pp. 131-136 : 132-133

Family Alexarasniidae Gorochov fam. n.

Type genus.

Alexarasnia gen. n.

Composition.

Only the genus Alexarasnia gen. n.

Diagnosis.

Tegmen (Figs 1-4) differs from that of Titanoptera , majority representatives of Orthoptera , and Paleozoic and Triassic Phasmatoptera in the absence of precostal area (presence of this area is a synapomorphy of all these orders). From the other representatives of two latter orders, this family differs in the reduction of Sc branches in the tegmen and/or clearly more numerous longitudinal tegminal veins (CuA has six or more branches in Alexarasniidae and four or less branches in all the other representatives of Phasmatoptera ). Tegminal venation of the new family is distinguished from that of all the other orders of Polyneoptera by the partly parallel longitudinal veins in combination with the following characters: straight CuP, very narrow radial and interradial areas, and reduction of branches of RA and RS (from Dictyoptera ); reduction of branches of Sc and/or RS, partial fusion of distal parts of some longitudinal veins with formation of long loop-like cells along anal edge of tegmen, and presence of intercalary veins between majority of longitudinal veins (from Grylloblattida as well as from the families Lemmatophoridae Sellards, 1909 and Atactophlebiidae Martynov, 1930 possibly belonging to the extinct order Eoblattida; Gorochov 2004); the latter characters as well as distal part of Sc not fused with RA (from Plecoptera and the other taxa of Eoblattida); tegmen not leathery with well-developed venation (from Dermaptera ), and distinctly more numerous longitudinal veins (from Embioptera ). Parallel venation of the tegmen is also present in the enigmatic family Chresmodidae Handlirsch, 1906 belonging to an unknown order of Polyneoptera ( Delclòs et al 2008; Zhang et al 2008a, b); Alexarasniidae is distinguished from it by the distal half of tegminal CuP situated not parallel to the anal tegminal edge and more numerous branches of CuA in tegmen (6-9 instead of 3-4).