Aphaenogaster mersa

Aphaenogaster mersa is one of fossil Aphaenogaster species, and one of three known from Baltic amber (the others being Aphaenogaster oligocenica and Aphaenogaster sommerfeldti). It is known from two specimens, the type specimen in the Geolog. Inst. Koenigsberg Coll. and a second reported by Dlussky & Rasnitsyn (2009). The type specimen, though in a small piece of amber, is not very clearly visible, owing to a thick white film which envelops the whole left side of the body and the whole gaster, and a crack which obscures the anterior portion of the head.

Identification
Differing from Aphaenogaster sommerfeldti in the following characters: The anterior border of the mesonotum does not project above the pronotum and the epinotal teeth are broader and blunter. The head and thorax and perhaps also the petiole and postpetiole are very coarsely reticulate rugose, and not longitudinally rugose, except on the front of the head.

Distribution
This taxon was described from Baltic Amber (Eocene).

Nomenclature

 * † mersa. †Aphaenogaster mersa Wheeler, W.M. 1915h: 55, fig. 20 (w.) BALTIC AMBER (Eocene).