Dhagnathos

†Dhagnathos; Temporal range: Early Cenomanian, Late Cretaceous K Pa Eo Ol Mi Pl Burmese amber, Kachin State, Myanmar
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	†Haidomyrmecinae
Genus:	†Dhagnathos; Perrichot, Wang & Barden, 2020
Type species
	†Dhagnathos autokrator;
Diversity
	1 fossil species; (Species Checklist)

Identification

Perrichot et al. (2020) - Large, robust ant, body length ca. 14 mm. Clypeus funnel-shaped resulting from extreme posterior expansion, extends well beyond antennal insertions, with lateral margins raised into carinae arising above mandible insertion and converging posteriorly to form a clypeal horn; horn bent forward at right angle from frons, its tip gently rounded, not spatulate, its underside deeply furrowed, forming a channel opening toward the labrum; clypeal carinae, including horn's edges, rimmed by stout, short, tooth-like denticles. Mandibles scythe-like, the elbow between basal and distal portions with a strong (isosceles) triangular blade pointing medially and ventrally, the apical portion long, curved upwards and backwards, acutely tapering to the tip and with dorsal (posterior) margin furrowed and serrated; mandibles widely spaced, approximated only apically, with medioventral blade not overlapping (in frontal view, when closed, with distal portions aligned with frontal carinae so that the labrum and clypeal area below horn are exposed). Labrum coated laterally by a brush of stiff, spine-like setae and long fine setae, dorsal surface sparsely covered by long fine setae, anterior margin glabrous. Antennae elongate, with flagellomeres thin and long. Ocelli and compound eyes large, the latter reniform.

Distribution

This taxon is known from Burmese amber, Kachin State, Myanmar (Early Cenomanian, Late Cretaceous).

Castes

Known from the queen caste.

Figure 3. Overview and details of alate females (gynes) of Dhagnathos autokrator gen. et sp. nov. Specimen HA03 (A), specimen XA01 (B), specimen RM1 (C–D), and holotype IGR.BU-003 (E–G). Habitus (A, B, C), fore wing (D), mandibles, clypeus and labrum in lateral views (E, F), wings, propodeum and petiole (G). Abbreviations: cc, lateral clypeal carina; cd, clypeal denticles; cp, clypeal process (horn); lss, labral spine-like setae; mib, mandibular medioventral blade; mp, mesal process of 1st gastral sternite; pdr, propodeal ridge; spp, sub-petiolar process. Scale bars: 2 mm (A–C), 1 mm (D, G), 0.5 mm (E, F).

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

†DHAGNATHOS [†Haidomyrmecinae]
- †Dhagnathos Perrichot, Wang & Barden, 2020: 4. Type-species: †Dhagnathos autokrator, by original desgination.

Etymology

The generic name is a combination of Dha, a single-edged sword with long, gently curved blade common throughout mainland Asia, and often called ‘the national sword of Burma’, and gnathos (Greek, meaning ‘jaw’), in reference to the mandibles' shape. The name is masculine.

References