Revision of Mesozoic fossils of the helophorid lineage of the superfamily Hydrophiloidea (Coleoptera: Polyphaga)
Fikáček Martin, Prokin Alexander, Angus Robert B., Ponomarenko Alexander, Yue Yanli, Ren Dong, Prokop Jakub
Acta Entomologica Musei Nationalis Pragae 52(1): 89-127, 2012
Abstract: A revision of the Mesozoic fossils belonging to the helophorid lineage of the
superfamily Hydrophiloidea is performed and an adapted classification is
suggested based on the phylogenetic analysis combining modern and fossil taxa of
the lineage. Three genera are revealed as basal extinct Mesozoic clades of the
helophorid lineage: Hydrophilopsia Ponomarenko, 1987, Laetopsia gen. nov. (adult
forms) and Cretotaenia Ponomarenko, 1977 (larval form). Mesosperchus
Ponomarenko, 1977 stat. nov. is resurrected from synonymy with Zetemenos Bode,
1953 and established as a formal subgenus of Helophorus Fabricius,
1775 containing probable stem taxa of that genus. Mesohelophorus Ponomarenko,
1977, stat. nov., is downgraded to a subgenus of Helophorus. Two new species are
described: Helophorus (Mesosperchus) inceptivus sp. nov. (Sharteg, Mongolia,
late Jurassic) and H. (M.) yixianus sp. nov. (Yixian Formation, China,
Jurassic-Cretaceous boundary). Mesohelophorus elongatus Ponomarenko, 1990, syn.
nov., is synonymised with Mesosperchus tarsalis Ponomarenko, 1977. The latter
species and Hydrophilopsia gracilis Prokin, Ren & Fikáček, 2010 are
transferred to Helophorus (Mesosperchus), resulting in the following new
combinations: Helophorus (Mesosperchus) tarsalis (Ponomarenko, 1977), comb. nov.
and H. (M.) gracilis (Prokin, Ren & Fikáček, 2010), comb. nov.
Mesohelophorus sibiricus Ponomarenko, 1977 is transferred to Helophorus
(Mesohelophorus) and the resulting secondary homonymy with Helophorus sibiricus
(Motschulsky, 1860) is removed by proposing a new substitute name Helophorus
palaeosibiricus nom. nov. for the former taxon. Hydrophilopsia baissensis
Ponomarenko, 1987, H. bontsaganica Prokin, 2009, H. hydraenoides Prokin, Ren
& Fikáček, 2010, H. mongolica Ponomarenko, 1987 and H. shatrovskiyi
Prokin, Ren & Fikáček, 2010 are transferred to Laetopsia gen. nov. The
inclusion of the fossil taxa into the helophorid lineage of the Hydrophiloidea
made the slight adaptation of the diagnosis of the genus Helophorus necessary.
Six fossil species included previously into the genera Helophorus, Mesosperchus
and Mesohelophorus are excluded from the helophorid lineage: Mesosperchus
notatus Ponomarenko, 1977, and M. schultzi Ponomarenko, 1985 (both transferred
to Polyphaga incertae sedis), Mesohelophorus mongolicus Ponomarenko, 1986
(transferred to Buprestoidea), Mesosperchus angulatus Ponomarenko, 1985
(confirmed as not belonging to the Hydrophiloidea), Tychon antiquum (Giebel,
1856) (confirmed as Coleoptera incertae sedis) and Helophoropsis brodiei
(Giebel, 1856) (transferred to Coleoptera incertae sedis). The genus Zetemenos
Bode, 1953 is transferred to Coleoptera incertae sedis based on the examination
of its type species, Z. sexlineatus Bode, 1953.
Key words: Hydrophiloidea, helophorid lineage, Helophoridae, Helophorus, Buprestoidea, new genus, new species, fossil record, Mesozoic, Jurassic, Cretaceous, China, Germany, Mongolia, Russia, United Kingdom