Dictyoraphidia Handlirsch, 1910

Makarkin, Vladimir N. & Archibald, S. Bruce, 2014, A revision of the late Eocene snakeflies (Raphidioptera) of the Florissant Formation, Colorado, with special reference to the wing venation of the Raphidiomorpha, Zootaxa 3784 (4), pp. 401-444 : 410

Genus Dictyoraphidia Handlirsch, 1910

Dictyoraphidia Handlirsch, 1910: 103 ; Handlirsch 1920 –1921 [1921]: 255; Martynov 1925a: 244; Cockerell & Custer 1925: 295; Carpenter 1936: 145; Metzger 1960: 41; Oswald 1990: 160 (as a synonym of Raphidia ); Aspöck et al. 1991: 536, 537, 665; Engel 2002: 21 (as a tentative synonym of Raphidia ).

Type and only species. Inocellia veterana Scudder, 1890 , by monotypy.

Diagnosis. Unusual Cenozoic raphidiopteran with many additional crossveins; origin of RP shifted basad in both wings; CuP simple in hind wing. Differs from Cretaceous (i.e., all other) baissopterid genera by 1r-m crossvein-like.

Remarks. Handlirsch (1910) characterized this genus “by the much greater development and ramification of the sector radii [= RP], by the much more numerous cross-veins, and consequently by the far greater number of cells” (p. 103). Carpenter (1936) thought that the type of Dictyoraphidia veterana was lost, and did not consider this genus and species in detail in his revision, but remarked that “his [Handlirsch’s] conclusions were based upon assumptions which are not valid, and his genera [ Dictyoraphidia and Archiraphidia ] based upon venational characteristics which appear in any series of specimens of Recent Raphidia ” (p. 145). But even as the genus was defined in Carpenter’s (1936) time, no species of Raphidia (i.e., in the broadest sense) had such dense venation as is found in Dictyoraphidia veterana .

We find that the venation of this genus most resembles that seen in the Baissopteridae . First, they share numerous crossveins, more than seen elsewhere in the Raphidiomorpha. Secondly, the simple CuA in the hind wing of D. veternana is a unique condition among Cenozoic fossil and extant Raphidioptera . This condition occurs in the hind wing of some Baissopteridae , e.g., Austroraphidia brasiliensi s ( Nel et al., 1990) from the Aptian Crato Formation of Brazil and Lugala longissima ( Ponomarenko, 1988) from the Early Cretaceous of Bayan-Tsagan, Mongolia ( Ponomarenko 1988: Fig. 4 ; Nel et al. 1990: Fig. 3 ). Even in other Baissopteridae , which have the richest venation of the Raphidiomorpha, CuA is usually only forked once. A simple CuP, however, is also present in two species of small Mesoraphidiidae (s.l.) with rather reduced venation, i.e., Archeraphidia yakowlewi Ponomarenko, 1988 and Nanoraphidia electroburmica . Thirdly, the structure of the pterostigma in most Baissopteridae is similar to that of the Raphidiidae , i.e., with a crossvein closing the pterostigma proximally and an incorporated branch of RA present; both of these conditions are present in Dictyoraphidia veterana . Fourthly, the origin of RP is shifted proximally (i.e., located in the proximal half of wings), a characteristic feature of most Mesozoic Raphidiomorpha. Therefore, there is little doubt that this genus belong to the Baissopteridae . The single important difference between it and all known species of Baissopteridae is that 1r-m of the hind wing is crossvein-like (an apomorphic state), whereas this is long, longitudinal in the latter (a plesiomorphic state). But this state could be convergent with the general evolution of this character in Cenozoic Raphidioptera (see Inocelliidae and Raphidiidae , above).

Baissopteridae have been recorded hitherto only from the Cretaceous. Their youngest previously known occurrence is in the Turonian (VM, pers. obs.); the oldest is in the Early Cretaceous (Mongolian and Transbaikalian localities). This finding of a Mesozoic family in the late Eocene with at least a 55 Ma absence in the record has an analogue in Neuroptera . Oligogetes relictus Makarkin, 1998 was described from the late Eocene/early Oligocene locality at Bolshaya Svetlovodnaya River, Primorskii Krai ( Makarkin 1998). It is the only Cenozoic Neuroptera genus which belongs to an extinct Mesozoic family with certainty (tentatively the Solenoptilidae ).

Figures

FIGURE 3. Dictyoraphidia veterana (Scudder, 1890). Holotype PU 6385, EM 1.385. A, the specimen as preserved today. B, forewing. C, hind wing. FW, forewing; HW, hind wing. Scale bars = 4 mm (B, C to scale).

FIGURE 4. Dictyoraphidia veterana (Scudder, 1890). Wing venation of the holotype PU 6385, EM 1.385. A, forewing. B, hind wing. Scale bar = 4 mm.