Microsaurus Dejean, 1833

Brunke, Adam James, 2023, Review of Quedius (Coleoptera, Staphylinidae) described from the 1934 expedition by R. Malaise to Myanmar, European Journal of Taxonomy 864, pp. 117-145 : 130

Subgenus Microsaurus Dejean, 1833

Remarks

This diverse subgenus is in great need of generic revision as it is rendered polyphyletic by several genera and subgenera of Quediini , including Malaisdius (see further comments above under “ Microsaurus lineage”). Currently, it is not possible to give a meaningful diagnosis of Quedius (Microsaurus) . The species groups listed below are redefined from Smetana (2017a), likely monophyletic and correspond to clades in Brunke et al. (2021). They will be treated in much greater detail in a future publication.

Apicicornis group, sensu nov.

Smetana (2017a) (and additional references listed therein) have recognized the Beesoni and Apicicornis species groups of Quedius (Microsaurus) as separate yet similar taxa that are commonly collected and abundant components of the East Palaearctic and Oriental fauna. Recently, it was shown that the Beesoni group rendered the Apicicornis group paraphyletic but they together formed a monophyletic ‘Clade D’ within the Microsaurus lineage, with the exception of Quedius masatakai Smetana, 2007 and Q. masasatoi Smetana, 2007 ( Brunke et al. 2021). Here the former two groups, minus the Masasatoi group (see below), are combined to form a newly defined Apicicornis species group that can be recognized globally within the lineage of Microsaurus by the following combination of character states: antennomeres 6–10 simple (not serrate or bipectinate) but inflated (i.e., not flattened, Fig. 5C ), antennomere 10 at most weakly transverse, many species with all antennomeres elongate; eyes large but with distinct temple, eye strongly protruding from head outline and with posterior frontal puncture situated at about the hind margin of eye ( Fig. 5D ); pronotum at least slightly explanate, with at least some marginal punctures removed from the marginal bead ( Fig. 5D ), anterior angles broadly rounded and with marginal bead entirely visible as seen in dorsal view ( Fig. 5D ); scutellum impunctate; elytral punctures uniform in size, setose and evenly distributed ( Fig. 5E ), in most species (not Q. rutilipennis and several others) fine and dense. The Apicicornis group as defined here should be treated as a separate genus but this is outside of the scope of this paper and a more thorough morphological study is needed for a formal description.

Figures

Fig. 5. A. Malaisdius ruficeps (Scheerpeltz, 1965), dorsal abdomen. B. M. smetanai gen. et sp. nov., dorsal abdomen. C–E. Quedius (Microsaurus) rutilipennis Scheerpeltz, 1965. C. Antenna. D. Pronotum (white arrow: marginal punctures removed from marginal bead; black arrow: anterior angles with marginal bead entirely visible in dorsal view). E. Elytra and basal abdomen. F. Q. (M.) masasatoi Smetana, 2007, pronotum (arrows indicating punctures of the dorsal row). Abbreviation: Pf = posterior frontal puncture. Scale bars: A–B, D–E = 1 mm; C, F = 0.5 mm.