Rotundicephala Tasaku, Ono & Maruyama, 2023
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publication ID |
https://doi.org/ 10.11646/zootaxa.5383.3.1 |
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publication LSID |
lsid:zoobank.org:pub:20988E42-C14D-4878-A716-8CEAB5E5EF92 |
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DOI |
https://doi.org/10.5281/zenodo.10361637 |
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persistent identifier |
https://treatment.plazi.org/id/03FE87D6-4253-FFE4-82AA-3E3A4B87FDCB |
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treatment provided by |
Plazi |
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scientific name |
Rotundicephala Tasaku, Ono & Maruyama |
| status |
gen. nov. |
Rotundicephala Tasaku, Ono & Maruyama , gen. n.
[Japanese name: Kuroshio-umi-hanekakushi-zoku]
Type species. Rotundicephala pacifica ( Sawada, 1971) , comb. n.
Diagnosis. This new genus is similar to Diaulota but can be distinguished by a combination of the following characteristics: tarsal formula 3-3-4, head almost circular ( Fig. 1C View FIGURE 1 ), body color usually reddish brown ( Fig. 14 View FIGURE 14 ). Abdomen is more elongate than that of Diaulota . See also the diagnosis of Diaulota .
Description. Body small; reddish brown in ground color, abdominal segments V–VII almost black in most cases, mouthparts and legs slightly paler. Head slightly convex or flattened, almost circular, as long as wide ( Fig. 1C View FIGURE 1 ); eyes small; infraorbital carina present; antennae 11-segmented, segments I–III strongly elongate, segment I longer than II, segment III shorter than II, segments IV–XI moniliform ( Figs. 15G–I View FIGURE 15 ). Labrum semicircular ( Fig. 16A View FIGURE 16 ). Mandibles almost symmetric, with one large tooth present around middle, and right teeth larger than left one ( Fig. 16E View FIGURE 16 ). Prementum without medial seta; ligula unilobed, very short, about 1/3 length of segment I of labial palpus; labial palpus two-segmented, segment I incompletely divided in basal 1/3, segment I very long, and segment II short and thin ( Fig. 16C View FIGURE 16 ). Maxilla slender; lacinia with about 8 spines; maxillary palpus 4-segmented, segment I very short, segment II three times as long as I, segment III longer than II, and segment IV as long as I ( Fig. 16D View FIGURE 16 ). Mentum almost trapeziform, anterior margin deeply emarginated ( Fig. 16B View FIGURE 16 ). Pronotum almost oval. Elytra short. Hind wings reduced. Tarsal formula 3-3-4. Abdomen oblong oval.
Male: tergite VIII with truncate apical margin; sternite VIII cuspidate at apical margin; apical lobe of median lobe unilobed and strongly curved, athetine bridge absent ( Figs. 15A, C & E View FIGURE 15 ); apical lobe of paramere narrow rectangle ( Fig. 2G View FIGURE 2 ).
Female: tergite VIII with truncate apical margin; sternite VIII rounded at apical margin.
Remarks. In a previous study, Sawada (1971) classified R. pacifica comb. n. within Diaulota , noting that there were no fundamental differences except for the tarsal formula from other Diaulota species. However, Yoo & Ahn (2021) suggested that R. koreana comb. n. may not actually belong to Diaulota . This study confirms that three species belonging to Rotundicephala gen. n. share two important morphological characteristics: a rounded head and a tarsal formula of 3-3-4. These two characteristics are not found in Diaulota . While the reduction of tarsi is often observed in Liparocephalini , the exclusive 3-3-4 tarsal formula is a distinctive character state of Rotundicephala gen. n. to distinguish it from Diaulota .
Etymology. The generic name means round head. Gender feminine.
Distribution. Japan: Honshû, Shikoku, Kyûshû; South Korea.
Key to the species of Rotundicephala gen. n.
1. Antennae long, reaching to elytra, collected from gravel beach.................................. R. koreana comb. n.
- Antennae short, not reaching to elytra, collected from rocky shore............................................... 2
2. Head and pronotum slightly convex, antennal segments IV–IX as long as wide......................... R. koheii sp. n.
- Head and pronotum flattened, antennal segments IV–VIII transverse.............................. R. pacifica comb. n.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.