Archemezira, HEISS & CHEN, 2023

HEISS, ERNST & CHEN, HUA-RONG, 2023, Archemezira nuoxichenae gen. et sp. nov. from Burmese amber (Heteroptera, Aradidae), Palaeoentomology 6 (1), pp. 17-21 : 17-18

Genus Archemezira gen. nov.

Type species. Archemezira nuoxichenae sp. nov.

Etymology. Refers to its age from Greek ‘archaios’ meaning earliest, ancestral and Mezirinae , the closest related flat bug subfamily.

Diagnosis. Distinguished from all Aradidae described so far from Burmese amber by a combination of characters that have not been observed together in other genera: large size; structure of head with a crest-like slender long and slender clypeus; antennae more than 2.5 times longer than width of head; no metathoracic scent glands; lateral margins of connexiva II-VII beset with spine-like teeth.

Description. Based on preserved outline and body structures of ventral side, as the whole dorsal side of pronotum, abdomen and pygophore are excavated and were obviously eaten by scavengers at a time, the specimen was already attached to resin by its ventral side before being totally covered by resin. The dorsal side of head is preserved. Therefore, the original alary condition might be macropterous or not and cannot be determined or reconstructed. Body size 15.4 mm.

Head. Distinctly longer than wide, narrow long clypeus produced anteriorly with a dorsal crest-like elevation; antennae long and slender, segment I shortest, apex of antenniferous lobes dentate; eyes subglobular, laterally protruding; rostrum arising from an open atrium, longer than head.

Thorax. About twice as wide as long, lateral margins subparallel at humeri, then angularly produced and sinuately constricted anteriorly to collar. Scutellum not preserved, no trace of hemelytral structures discernible.

Abdomen. Widely rounded, lateral margins of vltg IIVII with spine like teeth; sternites separated by transverse sutures; metathoracic scent glands and spiracles not discernible; apodemal impressions (glabrous areas of Usinger & Matsuda, 1959) hardly traceable, supposed pattern 2.2.1; pygophore conically produced posteriorly, wider than long.

Legs. Unarmed, femora slender with distinct trochanters, tibiae straight and cylindrical.

Remarks. The large size, general habitus and dentate lateral margins of abdomen of the new genus resemble the Oriental Mezirinae genus Acantharadus Banks, 1909 with its type species Acantharadus quaternarius ( Bergroth, 1886) redescribed by Usinger & Matsuda, 1959: 282 which is however differing from Archemezira nuoxichenae sp. nov. by a combination of characters as indicated in the diagnosis and in particular by the structure of clypeus, antenniferous lobes and antennae, shape and size of anterolateral angles of pronotum and the less acute dentation of connexival margins. Bergroth’s original illustration of the is reproduced here ( Fig. 1B ).

Archemezira gen. nov. shares some characters with the Archearadinae (e. g., elongate head, lateral expansions of connexiva), but it has no discernible metapleural scent glands while these are well visible in this subfamily and its type species Archearadus burmensis Heiss & Grimaldi, 2001 . Therefore, we tentatively place the new fossil in this subfamily. However, it might represent a new subfamily, but such decision should be based on a phylogenetic analysis as a result of careful comparison and examination of characters of extant and fossil Burmese amber taxa. Such a study is presently not feasible.

Figures

FIGURE 1. Archemezira nuoxichenae gen. et sp. nov. A, Holotype male, reconstruction of ventral view. B, Acantharadus quaternarius (Bergroth), original illustration of its description.clyp = elongated clypeus with open rostral atrium; ant = antenniferous lobes; eye = subglobular eyes; pron = pronotum; vltg II–VII = ventral laterotergites II–VII; ptg VIII = paratergite VIII; tVIII = tergite VIII. Scale bars = 3 mm.