Mesohelophorus, Ponomarenko, 1977

Fikáček, Martin, Prokin, Alexander, Angus, Robert B., Pono, Alexander, Marenko, Yue, Yanli, Ren, Dong & Prokop, Jakub, 2012, Revision of Mesozoic fossils of the helophorid lineage of the superfamily Hydrophiloidea (Coleoptera: Polyphaga), Acta Entomologica Musei Nationalis Pragae 52 (1), pp. 89-127 : 120

† ‘ Mesohelophorus ’ mongolicus Ponomarenko, 1986

( Figs. 94–99 , 120–123 )

Mesohelophorus mongolicus Ponomarenko, 1986: 94 .

Type locality and age. Mongolia, Kobdo province, Mayngad, section 221/17 (current GPS coordinates 48.1°N 91.6°E). Gurvan-Eren Formation, early Cretaceous, Berriasian, 145.5–140.2 mya ( CLAPHAM 2011c).

Material examined. HOLOTYPE: PIN 3152/4355 (piece and counterpiece). PARATYPE: PIN 3152/4312 (piece and counterpiece).

Taxonomic note. Both examined type specimens are very well preserved and show enough characters to be reliably placed into the superfamily Buprestoidea : eyes large and globular, antennae elongate without club, mentum situated rather anteriorly, narrowing anteriad, prosternum massive, with large (but not wide) prosternal process, mesoventrite with groove for reception of prosternal process, mesocoxae narrowly but distinctly isolated, metepimeron narrow posteriorly, largely widened anteriorly, metacoxae massive and subtriangular, five abdominal ventrites. Two characters would seemingly contradict the assignement in the Buprestoidea and indicate the possible placement in the Elateroidea: antennae are not serrate (but we suppose this is due to incomplete preservation causing that the detailed morphology of antennae cannot be estimated) and the prosternal process is rather narrow posteriorly (however, the shape of the process actually largely varies in the Buprestoidea, although a wide prosternal process is often considered as typical for the Buprestoidea; see e.g. COBOS 1986). We have also discussed the placement of M. mongolicus with the specialists on modern Buprestoidea (S. Bílý, V. Kubáň & M. Kalashian, pers. comm. to M. Fikáček, 2012) who all considered the placement to the Buprestoidea as well justified. For that reason, we are excluding the species from the Hydrophiloidea and transferring it to Buprestoidea.

Figures

Figs. 94–103. Taxa excluded from the hydrophilid lineage. 94–99 – ‘Mesohelophorus’ mongolicus Ponomarenko, 1986 (94–95 – PIN 3152/4355, holotype, piece and counterpiece; 96, 99 – PIN 3152/4312, piece and counterpiece; 97 – same specimen, detail of head in dorsal view; 99 – head and prosternum of the holotype). 100 – ‘Mesosperchus’ angulatus Ponomarenko, 1985, holotype; 101 – ‘Mesosperchus’ schultzi Ponomarenko, 1985, holotype, piece; 102–103 – ‘Mesosperchus’ notatus Ponomarenko, 1977, holotype (102 – general view; 103 – detail of elytral structure). Scale bars: 0.5 mm.

Figs. 120–123. ‘Mesohelophorus’ mongolicus Ponomarenko, 1986 (120–121 – PIN 3152/4355, holotype, piece and counterpiece; 122–123 – PIN 3152/4312, paratype, piece and counterpiece). Scale bars: 1 mm. Abbreviations: ant – antenna; prp – prosternal process.