Sosiak and her coworkers captured high-resolution photos and a 3D model of the lustrous, well-preserved brown ant, using photography and microscopic CT scans. They realized that, unlike most ant species, this insect lacked eyes and possessed jaws with sharp points, a single waist segment, and a sizable gland that would have released protective substances essential for subterranean life.
Although surprising, the discovery of the Baltic army ant makes sense, given that Europe was warmer and wetter throughout the insect’s existence, according to Sosiak.
The research team gave the ant the name Dissimulodorylus Perseus in honor of the Greek mythological figure Perseus, who defeated Medusa without being able to see her. The name is derived from the Latin term dissimulo, which means to conceal or hide.
This discovery will shine a light on the evolution of ants, and the places different ant species have been.
Among social insects, army ants are exceptional in their voracious coordinated predation, nomadic life history and highly specialized wingless queens: the synthesis of these remarkable traits is referred to as the army ant syndrome. Despite molecular evidence that the army ant syndrome evolved twice during the mid-Cenozoic, once in the Neotropics and once in the Afrotropics, fossil army ants are markedly scarce, comprising a single known species from the Caribbean 16 Ma. Here we report the oldest army ant fossil and the first from the Eastern Hemisphere (EH), Dissimulodorylus perseus, preserved in Baltic amber dated to the Eocene. Using a combined morphological and molecular ultra conserved elements dataset spanning doryline lineages, we find that D. perseus is nested among extant EH army ants with affinities to Dorylus. Army ants are characterized by limited extant diversification throughout most of the Cenozoic; the discovery of D. perseus suggests an unexpected diversity of now-extinct army ant lineages in the Cenozoic, some of which were present in Continental Europe.