Japanolaccophilus beatificus Balke & Hendrich 2019, sp. n.
Creators: name: Balke, Michael
name: Hendrich, Lars
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Dytiscidae
Japanolaccophilus
Japanolaccophilus beatificus

description: † Japanolaccophilus beatificus sp. n.
(Figs 1–3)
Type locality. Russia, Kaliningrad Region, Yantarnii (Jantarny) mine, around 54.867N 19.971E.
Age. Baltic amber is thought to be of middle Eocene age (Lutetian: 41.3–47.8 million years ago) (Wolfe et al. 2016).
Holotype (female). In a plastic box in the main collection of the Zoologische Staatssammlung München (ZSM) with a printed label: "Baltic amber from the Yantarnii (Jantarny) mine in the Kaliningrad region, Russia, obtained from Marius Veta. HOLOTYPE † Japanolaccophilus beatificus sp. n. Balke & Hendrich det. 2018".
Description. Beetle broadly ovate, length of beetle without head about 2.8 mm, with head about 3.0 mm; greatest width about 1.6 mm.
Surface sculpture. Head with polygonal meshes and fairly dense larger punctation except on frons and clypeus (Figs 2A, B). Pronotum with polygonal meshes and fairly dense larger punctation (Fig. 1). Pronotum surface in part appearing slightly deformed. Elytron with polygonal meshes and fairly dense larger punctation (Figs 1, 3A, D). Profemur and tibia dorsally and ventrally with coarse punctation (Figs 2A, B, 3C, G). Mesofemur and tibia dorsally and ventrally with coarse punctation. Metafemur ventrally with longitudinal meshes; metatibiae ventrally with longitudinal meshes but no coarse punctation, dorsally with coarse punctation. Metatarsomeres without coarse punctation (Figs 3A, B). Metacoxa with microreticulation of long diagonal cells, and without obvious punctation (Figs 3C, G). Sternites II, III and less so IV with diagonal lines, V, VI and VII with increasingly distinct fine microreticulation and large setiferous punctation.
Structures. Antennae filiform. Hind margin of pronotum almost straight, slightly concave in middle; hind angles broadly rounded. Prosternal process not extending beyond procoxae, broadened, somewhat deltoid (Figs 3C, F). Prosternal ridge not clearly visible, but possibly not with sharp ridge. Metaventrite also not well visible, lateral "wings" narrow. Metacoxal lines and metacoxal process not visible, this part of surface appearing deformed. Metatarsomeres with posteroapical margins weakly lobed compared to other Laccophilinae genera. Hind margin of sternite VII (= last visible ventrite) rounded, with fairly dense coarse setiferous punctation (Figs 3E, F).
Differential diagnosis. The extant Japanolaccophilus niponensis has the metatibia and metatarsomeres dorsally and ventrally with distinct coarse punctation, which is not present in † J. beatificus sp. n.. The last ventrite appears more densely punctate in † J. beatificus sp. n. than in J. niponensis.
Etymology. Latin adjective for "making happy", from beatum, happiness, in reference to the joyful discovery of this rare amber inclusion. The name is an adjective in the nominative singular.
Distribution. Only known from the type locality near Kaliningrad, Russian Federation. This is the first record of the genus outside Japan.
Habitat. Unknown. Assuming the dorsally visible suture between elytron and epipleuron is a derived character, this species would be member of a clade containing almost exclusively running water species (only one undescribed species of Neptosternus Sharp, 1882 from Timor was collected in large numbers in an intermittent stream pool, well away from running water). If † Japanolaccophilus beatificus sp. n. was also a running water species, its entrapment in resin might have occurred during a dispersal flight, or the species had a habitat other than related extant ones.
Note. In Toledo & Michat (2015), Japanolaccophilus is diagnosed as with lateral sides "not bordered in dorsal view", but this is not correct. Other genera with a dorsally well visible suture are the lotic American Laccodytes Régimbart, 1895, as well as the Afrotropical-Oriental-East Palearctic Neptosternus Sharp, 1882; the suture is faintly visible in the lotic New Guinean Philaccolilus Guignot, 1937. In the key of Miller & Bergsten (2016), Japanolaccophilus is in a group of genera diagnosed as having the posteromedial margin of pronotum angulate, but this is not really the case. Although there is a very subtle angle, we would describe the hind margin as "straight or almost so".
Additional material examined for comparison. Japanolaccophilus niponensis (Kamiya, 1939): 1 female: " JAPAN Kotchi-pref. Nishitosa vil. Kuroson 3 May 1992 M. Mori leg." (ZSM).
description: Published as part of Balke, Michael & Hendrich, Lars, 2019, † Japanolaccophilus beatificus sp. n. from Baltic amber and a key to the Laccophilinae genera of the World (Coleoptera: Laccophilinae), pp. 176-182 in Zootaxa 4567 (1) on pages 178-181, DOI: 10.11646/zootaxa.4567.1.10, http://zenodo.org/record/2592976