OMMATINAE Ponomarenko, 1969

Escalona, Hermes E., Lawrence, John F. & Ślipiński, Adam, 2020, The extant species of the genus Omma Newman and description of Beutelius gen. nov. (Coleoptera: Archostemata: Ommatidae: Ommatinae), Zootaxa 4728 (4), pp. 547-574 : 548

OMMATINAE Ponomarenko, 1969

Ommatinae Ponomarenko 1969: 82 . Crowson (1976); Lawrence (1999); Lawrence & Escalona (2019).

Diagnosis. Head constricted posteriorly to form a neck ( Fig. 14 ). Antennal insertions lateral, barely concealed by frontal ridges ( Fig. 22 ); subantennal grooves absent. Frontoclypeal suture absent; labrum fused to clypeus ( Fig. 14 ). Mandible tridentate with vertically aligned teeth ( Fig. 25 ), without mola or prostheca; its dorsal surface near base with setose cavity ( Fig. 18 ). Maxilla highly reduced, galea and lacinia slender, hyaline and setose, the latter without uncus ( Fig. 20 ). Apical maxillary and labial palpomeres ( Figs 19, 20 ) expanded and securiform with small circular cavity bearing sensilla near outer edge of upper surface ( Fig. 20 ; figs 4, 5 in Lawrence 1999; fig. 7G in Hörnschemeyer 2009). Mentum about as long as wide with deep basal pit and internal apodema ( Figs 85, 86 ; fig. 8A for Priacma serrata in Hörnschemeyer 2009 ). Gula longer than wide ( Fig. 15 ). Anterior part of gulamentum with subparallel longitudinal grooves extending from posterior tentorial pits to base of submental peduncle ( Fig. 21 ). Antennae relatively short, filiform to moniliform ( Figs 37, 38 ), rarely extending beyond base of prothorax ( B. rutherfordi ) and setose; antennomere 3 two or more times as long as 2 or 4. Median occipital endocarina present ( Fig. 36 ). Cervical sclerites absent. Pronotum with paired anterior and posterior deep impressions (also in Tetraphalerus Waterhouse ). Prosternum in front of coxae moderately long ( Fig. 40 ), partly or completely fused to pleuron, without paired crural impressions. Prosternal process often incomplete and short, narrowed apically and acute at apex. Notopleural suture complete to anterior edge ( Fig. 41 ). Procoxae with exposed protrochantins ( Fig. 41 ). Procoxal cavities slightly transverse, contiguous, open internally and open ( Fig. 40 ) or closed (e.g., Clessidromma palmeri Jarzembowski et al., 2018 ) externally. Epipleura narrow to broad and complete ( Figs 56, 57, 58, 62 ). Mesocoxae with exposed trochantins. Metaventrite narrowed anteriorly ( Fig. 51 ). Metanepisternum completely exposed. Metacoxae with weak coxal plates and exposed trochantins ( Fig. 52 ). Tarsi 5-5-5; pretarsal claws simple; empodium bisetose. Abdomen with narrow grooves between ventrites; tergites moderately sclerotised. Aedeagus with parameres completely fused to phallobase and partially fused together ( Figs 90–95 ).

Comments. This diagnosis is largely based on extant taxa. Recently described ommatid fossils like those listed in Lawrence & Escalona (2019), and particularly amber inclusions, require further detailed morphological research that may add to the classification of the family. We were able to examine some of those fossils, for example Stegocoleus Jarzembowski & Wang, 2016 (CNU) and Paraodontomma Yamamoto, 2017 (NIGP), which display morphological characters often used to distinguish extant Ommatidae from Cupedidae as well as Ommatinae from Tetraphalerinae . These characters include: head with tubercles ( Paraodontomma ), subantennal grooves present ( Stegocoleus ), prosternal process very short, and procoxal cavities externally closed ( Clessidromma Jarzembowski et al., 2018 ). A detailed taxonomic and phylogenetic study including all fossil Ommatidae is needed for better resolution to the current problematic classification of the extinct taxa.

Figures

FIGURES 14–21. Omma stanleyi: 14–19. Head (♀): 14, dorsal, 15, ventral, 16, lateral, 17, frontal, 18, mandible, dorsal; 19, Beutelius rutherfordi (paratype ♂): labial palp; 20, B. mastersi (♀): maxilla; 21, O. stanleyi: head, latero-ventral.

FIGURES 22–26. Beutelius sagitta (♀): 22–25. Head: 22, dorsal, 23, ventral, 24, latero–ventral, 25, frontal; 26, B. mastersi (♀) habitus, lateral.

FIGURES 85–95. Beutelius spp., mentum: 85–86. 85, B. mastersi, 86, B. rutherfordi (paratype ♂); 87, B. mastersi, mesonotum; 88, B. mastersi, pterothorax, ventral; 89, B. rutherfordi, pterothorax, ventral; aedeagus: 90–95. 90, Omma stanleyi; 91–92, B. mastersi; 93, B. reidi sp. nov.; 94, B. rutherfordi; 95, B. sagitta.

FIGURES 33–38. Beutelius rutherfordi (♂): 33–37. 33, head, dorsal, 34, head, ventral, 35, head, lateral, 36, head, dorsal (paratype ♂), 37, antenna. 38, B. sagitta, antenna.

FIGURES 39–44. Omma stanleyi (♀): 39–43. 39, pronotum, 40, prothorax, ventral, 41–42, prothorax, lateral, 43, scutellum; 44, Beutelius rutherfordi, prothorax, lateral (paratype ♂).

FIGURES 56–63. Beutelius sagitta (♂): 56, epipleuron, ventral view; B. rutherfordi (♂): 57, epipleuron, ventral view; O. stanleyi (♀) elytron: 58–60, 63. 58, ventral view with epipleuron, 59, dorsal, 60, internal, 63 dorsal; B. mastersi (♀) elytron: 61–62. 61, dorsal, 62, ventral view with epipleuron.

FIGURES 51–55. Omma stanleyi (♀): 51, pterothorax, ventral; 52, pterothorax, latero-ventral; 53, pterothorax and hind legs; 54, bifid mesoventral process; 55, abdominal ventrites 1 and 2 (in part).