Omma forte Li & Cai, 2021

Li, YanDa, Huang, DiYing & Cai, ChenYang, 2021, New species of Omma Newman from mid-Cretaceous Burmese amber (Coleoptera, Archostemata, Ommatidae), Deutsche Entomologische Zeitschrift 68 (2), pp. 341-348 : 341

publication ID

https://dx.doi.org/10.3897/dez.68.74174

publication LSID

lsid:zoobank.org:pub:F535A41F-8DC2-420D-81B0-94EBEE461B30

persistent identifier

https://treatment.plazi.org/id/5ECF739A-7BF6-4114-A95C-4B151973BFD1

taxon LSID

lsid:zoobank.org:act:5ECF739A-7BF6-4114-A95C-4B151973BFD1

treatment provided by

Deutsche Entomologische Zeitschrift by Pensoft

scientific name

Omma forte Li & Cai
status

sp. nov.

Omma forte Li & Cai sp. nov.

Figures 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4

Material examined.

Holotype, NIGP176634.

Etymology.

The specific name is from the Latin ‘fortis’, meaning strong, referring to the robust appearance of the species.

Locality and horizon.

Amber mine located near Noije Bum Village, Tanai Township, Myitkyina District, Kachin State, Myanmar; unnamed horizon, mid-Cretaceous, Upper Albian to Lower Cenomanian.

Description.

Body comparatively wide, about 9.3 mm long and 3.8 mm wide, tuberculate, with thin setae and scales.

Head (Fig. 3A, C View Figure 3 ) prognathous, seemingly wider than long. Neck region constricted, broad. Compound eyes comparatively large, protuberant. Antennal insertions located at anterior corners of head, separated by more than three diameters of antennomere 1. Subantennal grooves absent. Frontoclypeal suture absent. Labrum (Fig. 4A View Figure 4 ) transverse, with dentate anterior margin. Antenna (Fig. 3A View Figure 3 ) long, extending beyond base of prothorax when posteriorly directed, 11-segmented and filiform. Mandibles (Fig. 4B View Figure 4 ) tridentate with vertically aligned teeth. Maxillary and labial palps short, not reaching the level of the eyes when extending posteriorly (Figs 3C View Figure 3 , 4C View Figure 4 ); apical maxillary and labial palpomeres probably expanded and securiform.

Pronotal disc (Fig. 3B View Figure 3 ) widest in the anterior third, slight narrowing posteriorly; anterior corners rounded; lateral edges with distinct tooth-like tubercles (dentate) (Fig. 4D View Figure 4 ).

Scutellar shield (Fig. 4E View Figure 4 ) subtrapozoidal, wider posteriorly. Elytra (Figs 2 View Figure 2 , 3E, F View Figure 3 ) with ten rows of window punctures; lateral edges with distinct tooth-like tubercles (dentate); surface with ribbed slender scales (Fig. 4G View Figure 4 ); punctures in the ninth row distinctly transverse; interspace between eighth and ninth puncture rows thickened (Fig. 2 View Figure 2 ). Metaventrite narrowed anteriorly; discrimen present; metakatepisternal suture well developed (Fig. 4H View Figure 4 ). Metacoxae (Fig. 4H View Figure 4 ) strongly transverse with subconical mesal projections, contiguous, extending laterally to meet elytra, with weak coxal plates.

Hind wings (Fig. 3G, H View Figure 3 ) well developed. CuA forked; CuA1 fused with MP3+4; CuA3+4 fused with CuP+AA3; wedge cell present.

Legs long and slender. Tibiae with at least one well-developed spur. Tarsi long and slender; metatarsus especially long; metatarsomere 1 about as long as metatibia (Fig. 3D View Figure 3 ). Pretarsal claws simple.

Abdomen with five coplanar ventrites, separated by distinct grooves (Fig. 4I View Figure 4 ).

Remarks.

The new species can be confidently assigned to Omma . The length of maxillary and labial palps is a key diagnostic character separating Beutelius from Omma ( Escalona et al. 2020). Omma forte sp. nov. has short maxillary and labial palps, not reaching the level of the eyes, which is in accordance with Omma . The hind wing venation (especially the branching pattern of CuA) is another important character differentiating the two genera. In most beetle fossils preserved in amber, the hind wings are hidden by the elytra, and are thus not available for taxonomic purpose. Fortunately, the hind wings are partly exposed in the holotype of O. forte . In O. forte , the posterior branch of CuA (CuA3+4) is fused with CuP+AA3, closing the wedge cell, and the anterior branch of CuA (CuA1) is fused with MP3+4 (Fig. 3G View Figure 3 ), which matches perfectly with the venation of Omma stanleyi (fig. 64 in Escalona et al. 2020; fig. 4B in Lawrence et al. 2021), while the CuA of Beutelius is unforked (figs 67-68 in Escalona et al. 2020) or with an incomplete anterior branch only (fig. 4A in Lawrence et al. 2021).

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Ommatidae

Genus

Omma