Vertheia Jałoszyński & Perkovsky, 2016, gen. n.
Creators: name: Jałoszyński, Paweł
name: Perkovsky, Evgeny
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Vertheia

description: † Vertheia gen. n.
Type species: Vertheia quadrisetosa (here designated).
Diagnosis. A genus of Eutheiini with a pair of pits on posterior portion of frons, each pit connected to oblique groove extending posterolaterally; submentum long and subhexagonal; procoxae contiguous; mesocoxae broadly separated by flat and subtrapezoidal mesoventral process; elytra truncated at apices; basal elytral foveae absent or rudimentary.
Description. Body (Figs 49–64) elongate and flattened, with distinctly marked constriction between head and pronotum but weakly so between pronotum and elytra, BL below 1 mm.
Head capsule (Figs 49–54, 61–63) with anterior part (in front of occipital constriction) subtrapezoidal and transverse; eyes located posteriorly, large, strongly convex and moderately coarsely faceted; tempora (Figs 53, 61; tm) barely discernible, very short; occipital constriction (Figs 53, 61; occ) as broad as frons between eyes; frons (Figs 53, 61; fr) subtrapezoidal, posteriorly confluent with strongly transverse, subrectangular vertex (Figs 53, 61; vt); frons posteriorly with pair of small but distinct pits (Figs 53, 61; frp), each posteriorly connected to groove extending obliquely to posterolateral margin of vertex; 'neck' region (Figs 53, 61; nr) as broad as frons between eyes. Submentum (Fig. 63; smn) subhexagonal, about as broad as long; posterior tentorial pits (Fig. 61; ptp) distinct, located in transverse groove demarcating anteriorly the 'neck' region.
Antennae (Figs 49–54, 56–58, 61–62) moderately long and slender, with enlarged scape and pedicel and gradually but weakly thickened distally.
Pronotum (Figs 49–50, 52–54, 56–57, 61–62, 64) in dorsal view subrectangular with distinctly or slightly concave anterior margin, feebly marked and obtuse-angled anterior pronotal corners, rounded sides, distinct obtuse-angled posterior pronotal corners and arcuate posterior margin, slightly flattened in front of scutellum. Sides with distinct lateral pronotal carinae or edges (Fig. 64; lpc); base with shallow lateral antebasal impressions (Figs 53, 61; abi) and long, faint transverse antebasal groove (Figs 53, 61; abg).
Basisternal part of prosternum (Figs 55, 63; bst) nearly as long as coxal part, laterally demarcated by complete notosternal sutures (Fig. 55; nss); procoxae contiguous, indicating that prosternal process is either absent or very narrow and not elevated. Prothoracic hypomeron (Fig. 55; hy) flat and with distinctly demarcated inner (adcoxal) part by complete and recurved hypomeral ridge (Fig. 55; hyr). Shape of inner (adcoxal) hypomeral margin indicates that procoxal sockets are broadly open.
Mesoscutellum (Figs 53–54, 61–62) well-visible between elytral bases, broadly subtriangular, with indistinct median basal impression.
Mesoventrite (Fig. 55) with broadly subtrapezoidal and flat mesoventral intercoxal process (Fig. 55; msvp).
Metaventrite (Figs 55, 61; v3) subquadrate with weakly rounded sides, anteriorly at middle demarcated from mesoventrite; posteriorly strongly concave laterally in admetacoxal regions and medially forming very short and broad metaventral intercoxal process (Figs 55, 61; mtvp) with distinctly concave posterior margin.
Elytra (Figs 49–50, 53–54, 56–58, 61–62, 64) elongate and nearly oval, except for truncated apices; elytral base with foveae absent or rudimentary (indiscernible in studied specimens, in which the elytral base is wellexposed).
Hind wings not visible in studied specimens.
Legs (Figs 55, 63–64) moderately long, slender; pro- and mesocoxae suboval, metacoxae strongly transverse; all trochanters small and subtriangular; femora weakly clavate; tibiae slender, straight or nearly straight; tarsi long and slender, all tarsomeres elongate, slightly flattened.
Abdomen (Figs 55, 62–64) protruding from under truncated elytra, six sternites visible (Figs 55, 63–64; st3–8), sternite III only slightly longer than IV, sternites VII and VIII longest, suture between them partly indistinct. Pygidium (Fig. 62; pg) visible in dorsal view, subtriangular.
Distribution and composition. Vertheia is represented by one nominal and one undescribed species from the Eocene of Europe (Fig. 38), area currently within north-western Ukraine.
Etymology. The name Vert heia is a result of combining Veraphis and Eutheia, to underline the similarity of the fossil taxon to both these genera. Gender feminine.
Remarks. The new genus is placed in the tribe Eutheiini on the basis of the following characters: the body weakly constricted between the pronotum and elytra; the head with very short tempora and the occipital constriction as broad as vertex; the maxillary palpomere IV much smaller than III and not longer than broad; the pronotum with sharp lateral edges; the notosternal sutures present and complete; and the metacoxae broadly separated by short metaventral intercoxal process. The specimens found in Rovno amber have the maxillary palpomere IV clearly visible, which excludes a placement in the extant genus Paraneseuthia Franz, 1986a that lacks the palpomere IV (illustrated in Jałoszyński (2010). All remaining genera of Eutheiini have four-segmented maxillary palps, but Paeneutheia Jałoszyński, 2003, Euthiopsis Müller, 1925 and Euthiconus Reitter, 1881 have the palpomere IV very short, button-like (illustrated in Jałoszyński (2014b)), whereas that found in the studied fossil is distinctly subconical. Only the extant genera Eutheia Stephens,1830 and Veraphis Casey, 1897, and the extinct Early Cretaceous Archeutheia Jałoszyński & Peris, 2016 have the maxillary palpomere IV subconical. The new genus is very similar to all these three taxa in the general body form, the truncate elytral apices and the procoxae not separated by prosternal process. Vertheia has the pair of distinct pits on the posterior portion of the frons, with a groove extending from each pit posterolaterally; previously this character was thought to be a hallmark of Veraphis (illustrated in Jałoszyński & Hoshina (2005)), although some species of Eutheia have traces of similar pits or grooves, which are rather faint compared to those known in Veraphis (e.g., Jałoszyński (2008a, b)). Interestingly, although this character makes Vertheia very similar to Veraphis in dorsal view, the broad, flat and subtrapezoidal mesoventral intercoxal process in the Eocene taxon is not even remotely similar to the structure known in Veraphis. The latter genus has the mesoventral process narrowly carinate and elevated (illustrated in Jałoszyński (2014b)). The intermesocoxal region in Vertheia is nearly identical to that of Eutheia and Archeutheia. Vertheia differs from these two genera in absent or rudimentary basal elytral foveae (the elytral base is well exposed in two studied inclusions, but the foveae are not discernible), and from Archeutheia additionally in complete hypomeral ridges (absent in the Cretaceous taxon). Moreover, the submentum in Eutheia is short and transverse, whereas in Vertheia it is similar to that in Veraphis, i.e., long and subhexagonal.
The morphological structures of the new genus seem to represent a link between Eutheia and Veraphis, or possibly even an ancestral combination of characters, some of which have been preserved in extant species of these two genera. Key morphological characters of Eutheiini with four-segmented maxillary palps and conical palpomere IV are compiled in Table 2.
Eutheia Veraphis † Archeutheia † Vertheia
description: Published as part of Jałoszyński, Paweł & Perkovsky, Evgeny, 2016, Diversity of Scydmaeninae (Coleoptera: Staphylinidae) in Upper Eocene Rovno amber, pp. 1-85 in Zootaxa 4157 (1) on pages 17-18, DOI: 10.11646/zootaxa.4157.1.1, http://zenodo.org/record/262413