ARCHEOSMYLIDAE Riek, 1953

Winterton, Shaun L., Martins, Caleb Califre, Makarkin, Vladimir, Ardila-Camacho, Adrian & Wang, Yongjie, 2019, Lance lacewings of the world (Neuroptera: Archeosmylidae, Osmylidae, Saucrosmylidae): review of living and fossil genera, Zootaxa 4581 (1), pp. 1-99 : 11

ARCHEOSMYLIDAE Riek, 1953 (Permo-Triassic ‘stem lance lacewings’)

Type genus. Archeosmylus Riek, 1953: 85 .

Diagnosis. Forewing ovoid, costal area relatively narrow, wider basally, subcostal veinlets mostly simple, more widely spaced basally; subcostal crossveins not detected (due to poor preservation); Sc and RA fused distally and thence slightly curved posteriorly, entering wing margin well before apex; RP with numerous branches (more than nine); crossveins in radial area scarce, dense end-twigging along posterior margin of wing; M fork into MA and MP distal to the origin of RP1; MA and MP mostly dichotomously branched; CuA, CuP and 1A few-branched, poorly pectinate with irregular forking, branches with distal angle relatively acute; HW known only from small fragment.

Comments. Archeosmylidae has been considered a synonym of Permithonidae by previous authors (e.g., Whalley, 1988; Makarkin & Archibald, 2003; Engel & Grimaldi, 2008). We agree with the placement of Archeosmylidae as closely related to Osmylidae and Saucrosmylidae and it indeed likely represents a Permo- Triassic-aged stem group for these younger crown group families ( Riek, 1976; Makarkin et al., 2014; Engel et al., 2018). All three families have similar venation and differ mainly in the forewing configuration of the posterior vein fields. The veins CuA, CuP and A1 are weakly pectinate (weakly divergent branches) with few branches in Archeosmylidae while in osmylid genera these veins are more strongly pectinate with the branches strongly divergent and frequently arranged in a palisade-like pattern (see Makarkin et al., 2014). A condition similar to Archeosmylidae is found in Saucrosmylidae , but these families differ widely in other venation characters, principally associated with the larger wings of the latter and the consequent proliferation of secondary veins and crossveins. All three families also share the condition where FW Sc is fused with RA apically, ending on costal margin well before the wing apex. Some fossil and living taxa now placed in families such as Nymphidae and Osmylitidae were previously considered as being in Osmyloidea (e.g., Cratosmylus by Myskowiak et al., 2015), but all have the fused with Sc+RA vein joining the wing margin beyond the wing apex. Archeosmylidae have relatively few crossveins in the radial field, which are typically numerous in Osmylidae and Saucrosmylidae . Interestingly, the osmylid genus Sinosmylus is a typical member of Osmylinae but has secondarily convergent lack of radial crossveins except for two gradate series. Riek (1976) suggested that Archeosmylidae were stem group representatives of Osmylidae , although the absence of nygmata in Archeosmylidae is anomalous. Makarkin et al. (2014) discussed in detail the taxonomic composition and morphological characterisation of Archeosmylidae . Nygmata are widely considered as plesiomorphic for Neuroptera , being found in many distantly related lacewing families. The lack of nygmata in Archeosmylidae may represent a secondary loss in the clade, or simply even incomplete preservation in the compression fossil specimens of this family.

Genera included. Archeosmylus Riek ; Babykamenia Ponomarenko & Shcherbakov ; Lithosmylidia Riek.