Emplastus amguensis

Identification
A triangular radiomedial cell without stem is present in three species of this genus: Emplastus kozlovi (FWL 7.8–8.8 mm in males), Emplastus haueri (FWL 5.4 mm), and Emplastus miocenicus (FWL 10.1 mm). The latter, in addition to its significantly larger size, differs from the new species in the rectangular shape of the mediocubital cell. Emplastus haueri has a relatively short 3r cell and a smaller wing size. The greatest similarity is observed with Emplastus kozlovi from the Eocene marls of Bembridge, but the relatively longer mediocubital cell in E. amguensis (I(mcu) 0.7 and 0.5, respectively) has a different length ratio of 1M and m-cu. The wing sizes in the three species of this genus from Bolshaya Svetlovodnaya are somewhat smaller than in this species (Dlussky et al., 2015).

Wing venation indicates affiliation to Dolichoderinae. Although individually the features of venation in E. amguensis and E. kozlovi are found in extant representatives of several genera of Dolichoderinae, a certain combination of venation features in these imprints is unique (triangular rm, absence of 4RS, trapezoid mcu, and the ratio of 1M and m-cu, I(mcu)). Some extant Tapinoma have the most similar venation (e.g., specimen CASENT0109245, online catalog AntWeb.org), but, at the same time, a different shape of the mediocubital cell and a lower radial cell index (Ir = 0.5). There is also a strong similarity to the wing of the Aneuretinae; however, as noted above, in the absence of a body imprint, I do not consider this variant.

Distribution
This taxon was described from.

Nomenclature

 * †. †Emplastus amguensis Perfilieva, 2022: 415, fig. Plate 10, fig. 1 (q.) RUSSIA (Oligocene).

Type Material

 * Holotype. PIN, no. 3135/1, forewing imprint; Primorsky Krai, Tatar Strait, Terney District, right bank of the Kudya River, a tributary of the Amgu River; Lower Oligocene, Granatnenskaya Formation.