Succinoraphidia and ‘Mesoraphidiidae’

It is now clear that the Mesozoic ‘Mesoraphidiidae’ is a paraphyletic group, which includes in particular the stem lineages leading to extant Raphidiidae and Inocelliidae (Makarkin & Archibald 2014). The venation of Succinoraphidia is more similar to that of some ‘Mesoraphidiidae’ than the venation of any genus of Raphidiidae. Moreover, there are a few mesoraphidiids in which all diagnostic character states of Succinoraphidia are found (except for the structure of the pterostigma). It is characteristic of some minute species from the early Late Cretaceous, e.g., Grimaldiraphidia luzzii (Grimaldi, 2000) from the Turonian New Jersey amber; Nanoraphidia electroburmica Engel, 2002 and Burmoraphidia reni Liu et al., 2016 from the early Cenomanian Burmese amber. These genera are considered to belong to the tribe Nanoraphidiini (Bechly & Wolf-Schwenninger 2011; Liu et al. 2016). But the structure of their pterostigma differs from that of Succinoraphidia. It lacks the crossvein 2scp-r at the proximal end of the pterostigma (B. reni) or incorporated branches of RA within pterostigma (G. luzzii and N. electroburmica). However, the pterostigma of some other ‘Mesoraphidiidae’ from Burmese amber (e.g., Dolichoraphidia engeli Liu et al., 2016) is very similar to that of Raphidiidae with a long pterostigma, including Succinoraphidia, i.e., it possesses the crossvein 2scp-r at the proximal end of the pterostigma and the incorporated branch of RA within the pterostigma (see Liu et al. 2016: Fig. 4). The venation of Dolichoraphidia engeli differs from that of Raphidiidae only by the number of discoidal cells: one in D. engeli and normally two in all Raphidiidae, except some species, which have one discoidal cell in the hind wings, e.g., those of Harraphidia Steinmann, 1963 (see Monserrat & Papenberg 2006: Figs 1–4).

Judging from great similarity of the venation of Nanoraphidiini (and similar genera of the Late Cretaceous ‘Mesoraphidiidae’) and Succinoraphidia, among the former may be present a stem group leading to Raphidiidae.