Heteroptilon Carpenter, 1976

Aristov, D. S., 2020, Revision of the genera Heteroptilon, Nugonioneura and Opistocladus from the Lower Permian of USA (Insecta: Cnemidolestida: Tillyardembiidae, Nugonioneuridae and Parmapteridae), Far Eastern Entomologist 401, pp. 1-9 : 3-4

Genus Heteroptilon Carpenter, 1976

Heteroptilon Carpenter, 1976: 347 ; 1992: 126; Rasnitsyn, 2002: 112; Béthoux et al., 2003:

278.

Type species: Heteroptilon costale Carpenter, 1976, by original designation.

DIAGNOSIS. Forewing with costal fan in the base of subcostal field. Preradial field near the base of RS is very wide. Costal field near the base of RS is equal in width to subcostal one. SC ends right past wings mid length. Apex of SC and base of RS, which starts at the level of wings basal third, are drawn close. M merges with CuA near its base, M start branching at wings mid length. CuA branching at its apex, branching comb short.

SPECIES INCLUDED. Type species only.

NOTE. Family Heteroptilidae was erroneously synonimized under Tococladidae

(Hypoperlida) by reason of similarity of the genera Heteroptilon and Opistocladus

(Rasnitsyn, 2002). It was based mainly on RS drawn close to apex of SC, which ends in forking into C and R. This character is not unique for Opistocladus and is characteristic for many Cnemidolestidae ( Cnemidolestida ; see: Aristov, 2014).

From Tococladidae Heteroptilon differs in anastomosis of М+CuA and lacking of posterior branches of CuA in intercubital field. In Tococladidae М and CuA are connected by М 5, CuA with posterior branches in intercubital field (Carpenter,

1976; Béthoux et al., 2003).