Formica biamoensis, Dlussky & Rasnitsyn & Perfilieva, 2015

Dlussky, G. M., Rasnitsyn, A. P. & Perfilieva, K. S., 2015, The Ants (Hymenoptera: Formicidae) of Bol’shaya Svetlovodnaya (Late Eocene of Sikhote-Alin, Russian Far East), Caucasian Entomological Bulletin 11 (1), pp. 131-152 : 137

Formica biamoensis sp. n.

( Fig. 10)

Material. Holotype PIN3429/1141, lateral imprint of worker.Biamo.

Description. Worker. Body length about 7.5mm. Head oval. Eyes comparatively small, oval, markedly displaced backwards. Head 5times as long as maximum eye diameter. Gena 2.5–3times as long as maximum eye diameter. Mandible with acute apical tooth; teeth of masticatory margin not preserved. Funicular segments longer than wide. Mesosoma slender. Pronotum weakly convex in side view. Promesonotal constriction shallow. Propodeum angulated in side view; dorsal side nearly as long as declivous side. Petiole with thick vertical scale; in side view with convex posterior side and rounded top.

Measurements of holotype, mm: AL2.25; HL1.4; ED0.28.

Comparison is difficult to provide, for all other fossil workers are described after amber specimens using characters not available for our rock fossil. In general appearance, the new species is more similar to Formica flori Mayr, 1868 and F. gustawi Dlussky, 2003 from the Baltic amber which differ in having scale thicker and eyes smaller.

Etymology. After the former name of the type locality (Biamo).