Myrmica Ants (Hymenoptera: Formicidae) in Late Eocene European Ambers

Abstract

The genus Myrmica Latreille, 1804 from late Eocene European ambers is revised. The neotypes for M. longispinosa Mayr, 1868, M. rudis (Wheeler, 1915 and M. intermedia (Wheeler, 1915) are designated; four new species, Myrmica electrina sp. nov., M. dictyosa sp. nov., Myrmica damzeni sp. nov. and Myrmica saxonica sp. nov. are described; M. rudis and M. intermedia are recorded for Rovno amber for the first time. A key to identification of amber Myrmica species is compiled. Myrmica in mentioned ambers is the second species rich myrmicine genus. Only M. longispinosa can be assigned to the ritae-group; other 'ritae-like' species have either some putative plesiomorphies compared to this group, or putative apomorphy. M. electrina and M. saxonica are well distinguished from species of the ritae-group, but they are distinct from all extant Myrmica species and cannot be assigned to any modern species-groups. M. schaefersi Jessen, 2020 and M. nungesseri Jessen, 2020 from late Oligocene deposits fit well into the modern rugosa species group. In can be assumed that the putative ancestor of modern Myrmica lived in the warm forests of the early or middle Eocene, and by the late Eocene had already given rise to M. ritae-like species and other forms, and in the Oligocene species of the rugosa-group evolved.