Liparocephalini, Casey, 1894

Tasaku, Yuto, Ono, Hiroki & Maruyama, Munetoshi, 2023, Review of the intertidal rove beetle tribe Liparocephalini Fenyes (Coleoptera, Staphylinidae, Aleocharinae) from Japan, Zootaxa 5383 (3), pp. 251-296 : 290

publication ID	https://doi.org/ 10.11646/zootaxa.5383.3.1
publication LSID	lsid:zoobank.org:pub:20988E42-C14D-4878-A716-8CEAB5E5EF92
DOI	https://doi.org/10.5281/zenodo.10372471
persistent identifier	https://treatment.plazi.org/id/03FE87D6-4260-FFD6-82AA-3B1A4ACBF93B
treatment provided by	Plazi
scientific name	Liparocephalini
status

Treatment

Systematics of Liparocephalini View in CoL

In this study, we recognize six genera of Liparocephalini from Japan and found that they can be classified into three genus-groups: the Liparocephalus genus-group comprises Liparocephalus , Diaulota , and the newly described Rotundicephala gen. n.; the Amblopusa genus-group consists of Amblopusa and Halorhadinus . Lastly, we have the Paramblopusa genus-group including only Paramblopusa . Within these delineated groups, the Liparocephalus and Amblopusa groups share notable similarities in the structure of the labial palpus: typically comprising two palpomeres, occasionally three, with palpomere II generally commensurate in width to palpomere I. The palpomere I is conspicuously longer than II, as visually depicted in Figures 4C View FIGURE 4 , 7D View FIGURE 7 , 8C View FIGURE 8 , 10C View FIGURE 10 , 12C View FIGURE 12 , 16C View FIGURE 16 , 19C View FIGURE 19 , and 20D View FIGURE 20 . It is highly plausible that these two genus groups, inclusive of the type genus of the tribe, represent monophyletic assemblages, collectively constituting the core Liparocephalini . Conversely, the Paramblopusa group is distinguished from these core Liparocephalini through the 3-palpomere labial palpus, with palpomere II being more slender than I, as in Figure 22C View FIGURE 22 . These distinctive characteristics render its inclusion within the Liparocephalini taxon less tenable. A comprehensive inquiry is requisite to ascertain the precise taxonomic placement of Paramblopusa .

Other genera within Liparocephalini , namely Ianmoorea Ahn, 2006 , distributed in New Zealand, and Ashella Klimaszewski, 2020 , known from the US, exhibit a stronger affinity with the Salinamexus Moore & Legner, 1977 , which currently holds an uncertain tribal classification ( Maruyama, 2011; Newton, 2022), than the core Liparocephalini . Notably, Ianmoorea and Salinamexus share the following characteristics: a diamond-shaped apical lobe of the paramere ( Fig. 14 View FIGURE 14 in Ahn, 2004; Figs. 12 View FIGURE 12 , 21 View FIGURE 21 , 31 in Maruyama, 2011); a depressed apical margin of male tergite VIII ( Fig. 11 View FIGURE 11 in Ahn, 2004), and a trapezoidal mentum with a truncate anterior margin ( Fig. 9 View FIGURE 9 in Ahn, 2004; Fig. 6 View FIGURE 6 in Jeon & Ahn, 2007). While Ashella has not yet illustrated its mouthparts, the body shape ( Fig. 21 View FIGURE 21 . 259a in Klimaszewski, 2020) and the shape of the male tergite VIII ( Fig. 21 View FIGURE 21 . 259d in Klimaszewski, 2020) bear resemblance to those of Salinamexus ( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 , 9 View FIGURE 9 , 18 View FIGURE 18 & 27 in Maruyama, 2011). Furthermore, the characteristics of the mentum and male tergite VIII, though they exhibit homoplasy, are also shared with Actocharis Sharp, 1870 , the sole genus of the tribe Actocharini Bernhauer & Schubert, 1911 known from the western Palearctic coastal region ( Figs. 2 View FIGURE 2 , 3b View FIGURE 3 & 4b View FIGURE 4 in Assing, 1992). We hypothesize that these four genera are likely closely related, and Ianmoorea and Ashella are provisionally excluded from Liparocephalini . In Orlov et al. (2021), Actocharis (Actocharini) is postulated as a sister group or ingroup of Liparocephalini . However, their analysis did not encompass the Amblopusa group of Liparocephalini , and the accurate systematic position of Actocharini and monophyly of the aforementioned four genera still necessitate further discussion.

Baeostethus Broun, 1909 View in CoL cannot be thoroughly discussed as important characteristics are not described in Pace (1989) and Leschen et al. (2002), but the dorsal habitus ( Fig. 1I View FIGURE 1 in Orlov et al., 2020) shows striking similarities to the Liparocephalus View in CoL group. Here we regard it as incertae sedis within Liparocephalini View in CoL .

Hence, we consider the core Liparocephalini View in CoL with five genera: Liparocephalus View in CoL , Diaulota View in CoL , Rotundicephala gen. n., Amplopusa, and Halorhadinus View in CoL . The affiliation of other genera will need to be addressed in future studies.

The coastal Aleocharinae are taxonomically not well understood due to their similar morphological specialization resulting from coastal adaptation. Moreover, the misidentification highlighted in this study has further contributed to the confusion. Although most of these issues have been resolved in our study, future phylogenetic analyses of the entire subfamily Aleocharinae will be necessary to elucidate their relationships with other tribes.