A new Cretaceous family of enigmatic two-winged lacewings (Neuroptera)

Lacewings (Neuroptera) normally bear four well-developed wings. There are a few brachypterous, micropterous or apterous species, found in several extant families; this wing reduction is usually associated with flightlessness. The only documented fossil neuropteran with reduced hind wings (modified to small haltere-like structures) is the enigmatic minute genus Mantispidiptera Grimaldi from the Late Cretaceous amber of New Jersey. In this paper, we report a new genus and species from the Early Cretaceous Yixian Formation of China (Dipteromantispa brevisubcosta n. gen. et n. sp.) resembling Mantispidiptera. We place these two genera in the new family Dipteromantispidae, n. fam. They bear well-developed forewings with reduced venation, and hind wings that are extremely modified as small structures resembling the halteres of Diptera. Dipteromantispidae n. fam. might be specialized descendants of some early Berothidae or of stem group Mantispidae þ Berothidae. We presume that dipteromantispids were active fliers. This is a remarkable example of parallel evolution of wing structures in this neuropteran family and Diptera.