Temporal range: Bartonian, Middle to Late Eocene Bitterfeld amber, Sachsen-Anhalt, Germany
Dubovikoff & Dlussky, 2019
E. exsectus differs from the type species of the genus by shorter head and scapus, the structure of the propodeum (the basal surface is much shorter than the declivous) and petiole (vertical high node).
Key to the species of the genus Eldermyrmex
- Head long (CI 158), with subparallel sides and straight occipital margin. Basal surface of propodeum is more long than declivous (Pl. 1, figs. 1, 2). Petiole with small conical node inclined forward => Eldermyrmex oblongiceps
- Head shorter (CI 120), with convex sides and deeply concave occipital margin. Basal surface of propodeum distinctly shorter than declivous. Petiole with high vertical conical node (Pl. 1, figs. 5, 6) => Eldermyrmex exsectus
This taxon was described from Bitterfeld amber (Bartonian, Middle to Late Eocene).
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- †exsectus. †Eldermyrmex exsectus Dubovikoff & Dlussky, 2019: 995, figs. 3-6 (w.) BITTERFELD AMBER (Eocene).
- Holotype, worker, Bitterfeld Amber (Eocene), 11/206, Berlin Museum für Naturkunde der Humboldt-Universität.
This specimen is clearly visible but partially deformed. It seems may have been heated. Head and mesosoma with longitudinal cracks in the cuticle, the legs are slightly stretched and damaged. Petiole and abdomen are separated from mesosoma.
Worker (Pl. 1, figs. 3–6). Body length about 3 mm. Head moderately short (CI 120) and wide, its length 1.2 times more than width, with convex sides and deeply concave occipital margin. Ocelli are absent (Pl. 1, fig. 3). Eyes are small and shifted forward (Pl. 1, fig. 4). Anterior margin of clypeus concave (slightly notched). Anterolateral angles of clypeus distinct. Mandibles triangular, massive, with short teeth (hard to see). Scapus short, does not reach occipital margin; its length is 1.25 times less than width of head. Flagella is not preserved. Mesosome narrow, noticeably narrower than head. Mesosomal seams well expressed, distinct. Mesonotum in profile, slightly raised above pronotum. Basal surface of propodeum distinctly shorter than declivous. Propodeum is compressed from the sides, its sides are almost vertical, with distinct lateral edges. Basal and declivous surfaces with shallow medial impression. Petiole with high vertical conical node. Body smooth and shiny, without standing hairs.
Measurements, in mm: HL 0.79, HW0.66, EL 0.12, SL 0.52, VL 0.39, WL 0.84, PEL 0.17, F3 0.55, GL 1.19, TL 3, CI 120, EI 18, SI 66.