Retromalisus Kazantsev 2020, gen. nov.
Creators: name: Kazantsev, Sergey
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Berendtimiridae
Retromalisus

description: Retromalisus Kazantsev, gen. nov.   
 Type species. Retromalisus damzeni sp. nov., by present designation.   
 Description. Adult male (?). Alate, flattened, elongate. Head moderately large, transverse, exposed, smoothly narrowed posteriorly, ventrally noticeably semi-circularly excavated medially. Eyes relatively small, spherical. Palps small, slender; ultimate palpomeres elongate, narrowed and pointed apically. Bases of antennae widely separated; antenna 11- segmented, moderately long, filiform; pedicel (antennomere 2) elongate, about as long as antennomere 3, antennomere 3 slightly shorter than antennomere 4; pubescence on antennomeres 3–15 short, dense and suberect (Figures 1–4).   
Pronotum transverse, but distinctly narrower than elytra, trapezoidal, with slightly convex anterior and posterior margins and small acute posterior angles with noticeable incision in front of them; disk medially with obscure longitudinal rib, laterally with slightly more pronounced transverse carinae reaching lateral margins; margins narrowly bordered (Figures 3–5). Prosternum short, T-shaped, with slightly convex medially anterior margin and short bifurcate intercoxal process (Figures 3–4). Scutellum triangular (Figure 1). Metaventrite transverse, conspicuously widening posteriorly (Figure 2). Elytra elongate, almost parallel-sided, only slightly narrowed in the middle, shining, with 10 regular longitudinal rows of round punctures (eight in distal fifth) and fully sclerotised narrow epipleures attaining to elytral apices. Metathoracic wings fully developed; both anterior and posterior edges with a fringe of short hairs (Figures 1–2).  
Legs relatively long and slender; front and middle coxae elongate, apices of hind coxae elongate and separated; trochanters elongate, apically overlaying bases of femurs; femurs and tibiae straight, narrow, subequal in length; tibial spurs small but well visible; tarsi 5-segmented, tarsomeres 1–3 narrow, without plantar pad, tarsomere 4 incised to the base and conspicuously widened; claws simple (Figures 1–2).  
Abdomen with eight ventrites first medially completely interrupted by metacoxae; penultimate ventrite broadly semi-circularly incised; ultimate ventrite largely invaginated, its exposed portion transverse, rather deeply semicircularly incised (Figures 2, 6).  
 Female. Unknown (the shape of the last abdominal segments suggests that the studied specimen is probably a male).   
 Etymology. The name of the new genus is a combination of ‘retro’, the Latin for ‘backward’, and the genus name ‘ Omalisus ’, alluding to its certain similarity to the latter taxon. Gender masculine.   
 Differential diagnosis. Retromalisus gen. nov., is easily distinguishable from Berendtimirus, the only other member of the family, by the smaller eyes, shorter scapus (antennomere 1), narrower mandibles, shorter antennae and 10 longitudinal rows of elytral punctures (vs. nine in Berendtimirus) (Figures 1–4). The number of ventrites in Retromalisus gen. nov. (eight) is also noticeably greater than that in Berendtimirus (six), this difference addressed in the Discussion section below.   
 Remark. Retromalisus gen. nov. cannot be referred to Cantharidae due to its complete sclerotised elytral epipleures reaching elytral apices, while in all studied cantharids the epipleures are short, developed mostly at the humeral area (e.g. Kazantsev 2005). Neither can it be placed in Omalisinae (Elateridae) due to the short prosternum with short intercoxal process and wide and deeply incised penultimate tarsomeres, as omalisines are characterised by the long prosterna with long intercoxal processes and narrow tarsi (e.g. Bocák and Brlik 2008). The shape of the ultimate ventrite in Retromalisus gen. nov. is also quite unusual for males of the Omalisinae lineage, where the ultimate ventrite is always elongated and much narrower than the penultimate one (e.g. Bocák and Brlik 2008).
description: Published as part of Kazantsev, Sergey, 2020, Retromalisus damzeni, gen. et sp. nov., a second Baltic amber taxon of the extinct family Berendtimiridae (Insecta: Coleoptera), pp. 1073-1080 in Journal of Natural History 54 (17 - 18) on pages 1074-1075, DOI: 10.1080/00222933.2020.1781949, http://zenodo.org/record/5753671