Dicliptera

This group includes the Diathemoptera and Permoth-emistida; however, it was referred to as Martynov's Archodonata in Kluge's (2000) treatment of palaeopterous insects. We prefer the more descriptive name Dicliptera, in reference to the vestigial or absent hind wings. Dicliptera are notable among palaeodictyopterids for an absence of paranotal lobes and archedictyon, presence of a distinct pterostigma (as a heavily infuscated region, and not formed of fused or expanded veins as in Hymenoptera), reduction

6.19. Dunbaria fascipennis from the Early Permian of Elmo, Kansas. The wings of some species of paleodictyopterans had striking patterns. YPM 1002a; wing spread 35 mm.

6.20. Some palaeodictyopterans reached gigantic proportions. An example is Moravia grandis from the Early Permian of Midco, Oklahoma, which is preserved as a small portion of the hind wing here. MCZ 8647; preserved length 73 mm.

6.21. The large paleodictyopteran Lithomantis carbonarius from the Late Carboniferous of Scotland. Although faint in this specimen, the large paranotal lobes of the first thoracic segment are visible and give the impression of a "six-winged" insect. NHM 1.8118; preserved width 89 mm.

6.20. Some palaeodictyopterans reached gigantic proportions. An example is Moravia grandis from the Early Permian of Midco, Oklahoma, which is preserved as a small portion of the hind wing here. MCZ 8647; preserved length 73 mm.

or complete loss of the hind wings, and reduction of crossveins to a single rs-m vein. The Diathemoptera (e.g., Diathemidae) were clearly more primitive owing to the presence of vestigial hind wings, while permothemistids had lost the hind wings entirely. The reduced crossvenation is likely a derived feature uniting the group with the Megasecoptera. The absence of paranotal lobes and reduced venation could be characters uniting the Dicliptera with the Protohymenoptera and Eumegasecoptera in the Megasecoptera. In the latter two groups the wings are "costalized" (veins C, Sc, and R are tightly brought together along the anterior margin of the wing) and petiolate, while the Dicliptera have broader wings and are not costalized. Dicliptera are presently recorded only from the Permian of Eurasia but likely extended into the Late Carboniferous. Kansasiidae is a possible diclipteran (near Diathemidae)

6.21. The large paleodictyopteran Lithomantis carbonarius from the Late Carboniferous of Scotland. Although faint in this specimen, the large paranotal lobes of the first thoracic segment are visible and give the impression of a "six-winged" insect. NHM 1.8118; preserved width 89 mm.

from the Early Permian of North America (Tillyard, 1937a; Demoulin, 1954b).

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