The click beetles (Elateridae) represent the major and well-known group of the polyphagan superfamily Elateroidea. Despite a relatively rich fossil record of Mesozoic Elateridae, only a few species are described from the Upper Cretaceous Burmese amber. Although Elateridae spend most of their lives as larvae, our knowledge on immature stages of this family is limited, which is especially valid for the fossils. So far, only a single larval click beetle has been reported from Burmese amber. Here, we describe two larval specimens from the same deposit which based on their morphology unambiguously belong to the predominantly Southern Hemisphere subfamily Pityobiinae, being the most similar to the representatives of tribe Tibionemini. However, since the larvae of the closely related bioluminescent Campyloxenini have not yet been described, we place our specimens to Tibionemini only tentatively. One species of Pityobiinae was recently described from Burmese amber based on adults, and we discuss if it can be congeneric with the here-reported larvae. Recent representatives of the Tibionemini + Campyloxenini clade are known from South America and New Zealand, and this group is hypothesized to have a Gondwanan origin. Hence, the newly discovered Burmese amber larvae may further contribute to a recently highly debated hypothesis that biota of the resin-producing forest on the Burma Terrane, which was probably an island drifting northward at the time of amber deposition, had at least partly Gondwanan affinities. The discovery of enigmatic click beetle larvae in the Upper Cretaceous Burmese amber sheds further light on the palaeodiversity and distribution of the relatively species-poor Gondwanan clade of click beetles, which contain a recent bioluminescent lineage, as well as on the taxonomic composition of the extinct Mesozoic ecosystem.

• Klíčová slova
• Australia, Distribution, Elateridae, Fossil, Morphology, Pityobiinae,
• MeSH
• brouci * anatomie a histologie   klasifikace   MeSH
• fylogeneze MeSH
• jantar * MeSH
• larva * anatomie a histologie   MeSH
• zkameněliny * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Myanmar MeSH
• Názvy látek
• jantar * MeSH

Gondwanan elaterids, previously thought to be unrelated, include bioluminescent Campyloxenus earlier placed in bioluminescent Pyrophorinae. Genomic data suggest close relationships between Gondwanan groups. We maintain Morostomatinae and Hapatesinae and redefine Pityobiinae with Nearctic Pityobiini, Gondwanan Parablacini stat. nov., Campyloxenini stat. nov., and Tibionemini trib. nov. Their ancestors putatively underwent differentiation in Gondwana during the Cretaceous separation of southern continents. In contrast with their age, extant groups are species poor. Campyloxenus represents a recent origin of bioluminescence, no older than ∼53 my. Its large pronotal lanterns differ from Pyrophorini and resemble color patches of sympatric beetle co-mimics. This discovery highlights the fourth or fifth origin of bioluminescence in Elateroidea, alongside the lampyroid clade, click beetles Pyrophorini, Alampoides and Coctilelater in Anaissini (Pyrophorinae), and Balgus schnusei (Thylacosterninae). While our phylogenetic findings illuminate the phylogenetic aspects, the complete story awaits further field observations and in-depth genomic analyses of biochemical pathways used by bioluminescent elateroids.

• Klíčová slova
• Entomology, evolutionary biology, phylogenetics,
• Publikační typ
• časopisecké články MeSH

Rhagophthalmidae are a small beetle family known from the eastern Palaearctic and Oriental realms. Rhagophthalmidae are closely related to railroad worms (Phengodidae) and fireflies (Lampyridae) with which they share highly modified paedomorphic females and the ability to emit light. Currently, Rhagophthalmidae include 66 species classified in the following 12 genera: Bicladodrilus Pic, 1921 (two spp.), Bicladum Pic, 1921 (two spp.), Dioptoma Pascoe, 1860 (two spp.), Diplocladon Gorham, 1883 (two spp.), Dodecatoma Westwood, 1849 (eight spp.), Falsophrixothrix Pic, 1937 (six spp.), Haplocladon Gorham, 1883 (two spp.), Menghuoius Kawashima, 2000 (three spp.), Mimoochotyra Pic, 1937 (one sp.), Monodrilus Pic, 1921 (two spp. in two subgenera), Pseudothilmanus Pic, 1918 (two spp.), and Rhagophthalmus Motschulsky, 1854 (34 spp.). The replacement name Haplocladongorhami Kundrata, nom. nov. is proposed for Diplocladonhasseltii Gorham, 1883b (described in subgenus Haplocladon) which is preoccupied by Diplocladonhasseltii Gorham, 1883a. The genus Reductodrilus Pic, 1943 is tentatively placed in Lampyridae: Ototretinae. Lectotypes are designated for Pseudothilmanusalatus Pic, 1918 and P.marginalis Pic, 1918. Interestingly, in the eastern part of their distribution, Rhagophthalmidae have remained within the boundaries of the Sunda Shelf and the Philippines demarcated by the Wallace Line, which separates the Oriental and Australasian realms. This study is intended to be a first step towards a comprehensive revision of the group on both genus and species levels. Additionally, critical problems and prospects for rhagophthalmid research are briefly discussed.

• Klíčová slova
• Catalogue, Drilidae, Lampyridae, Oriental Region, Phengodidae, classification, neoteny,
• Publikační typ
• časopisecké články MeSH

The soft-bodied click-beetle genus Malacogaster Bassi, 1834 from the Mediterranean region has never been taxonomically revised to date. Information on its morphology, intra- and interspecific variability, systematics and distribution is fragmented and most species have not been properly studied since their description. Therefore, in this study we summarize all available information on the genus Malacogaster. Altogether, we recognize 10 valid species from the area including the Canary Islands, Iberian Peninsula, Balearic Islands, northern coast of Africa, Sardinia, and Sicily. Malacogaster ruficollis Dodero, 1925, stat. nov., which was originally described as a variety of M. bassii Lucas, 1870 and later synonymized with it, is considered a separate species. Malacogaster parallelocollis Reitter, 1894, syn. nov. and M. olcesei var. reductus Pic, 1951, syn. nov. are synonymized with M. maculiventris Reitter, 1894. Malacogaster notativentris Pic, 1951, syn. nov. and M. olcesei Pic, 1951, syn. nov. are synonymized with M. passerinii Bassi, 1834. Lectotypes are designated for M. maculiventris Reitter, 1894, M. nigripes heydeni Reitter, 1894, M. parallelocollis Reitter, 1894, M. thoracica Redtenbacher, 1858, M. olcesei Pic, 1951, and M. rubripes Peyerimhoff, 1949 to fix their identity.

• Klíčová slova
• Africa, Cantharoidea, Coleoptera, Elateroidea, Italy, Spain, identification key, neoteny, systematics,
• Publikační typ
• časopisecké články MeSH

We understand very little about the timing and origins of bioluminescence, particularly as a predator avoidance strategy. Understanding the timing of its origins, however, can help elucidate the evolution of this ecologically important signal. Using fireflies, a prevalent bioluminescent group where bioluminescence primarily functions as aposematic and sexual signals, we explore the origins of this signal in the context of their potential predators. Divergence time estimations were performed using genomic-scale datasets providing a robust estimate for the origin of firefly bioluminescence as both a terrestrial and as an aerial signal. Our results recover the origin of terrestrial beetle bioluminescence at 141.17 (122.63-161.17) Ma and firefly aerial bioluminescence at 133.18 (117.86-152.47) Ma using a large dataset focused on Lampyridae; and terrestrial bioluminescence at 148.03 (130.12-166.80) Ma, with the age of aerial bioluminescence at 104.97 (99.00-120.90) Ma using a complementary Elateroidea dataset. These ages pre-date the origins of all known extant aerial predators (i.e. bats and birds) and support much older terrestrial predators (assassin bugs, frogs, ground beetles, lizards, snakes, hunting spiders and harvestmen) as the drivers of terrestrial bioluminescence in beetles. These ages also support the hypothesis that sexual signalling was probably the original function of this signal in aerial fireflies.

• Klíčová slova
• Lampyridae, aposematism, divergence time estimation, phylogeny, predation,
• MeSH
• brouci * MeSH
• Chiroptera * MeSH
• fylogeneze MeSH
• genomika MeSH
• světluškovití MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Paedomorphosis is a heterochronic syndrome in which adult individuals display features of their immature forms. In beetles, this phenomenon occurs widely in the superfamily Elateroidea, including the net-winged beetles (Lycidae), and, due to the usual flightlessness of paedomorphic females, it is hypothesized to cause speciation rates higher than in non-paedomorphic lineages. However, some fossils of paedomorphic lycids do not support this with palaeobiological data. Discovery of new Lycidae fossils attributed to the West Indian extant paedomorphic genus Cessator Kazantsev in the Dominican amber also suggests morphological stasis within this genus in the Greater Antilles. We describe Cessator anachronicus Ferreira and Ivie, sp. nov. based on adult males, as well as the first ever recorded fossil net-winged beetle larva of the same genus. We propose that the relatively young age of the studied fossils combined with the stable conditions in the forest floor of the Greater Antilles through the last tens of million years could explain the exceptionally conserved morphology in the net-winged beetles affected by the paedomorphic syndrome.

• MeSH
• brouci * anatomie a histologie   MeSH
• jantar * MeSH
• lesy MeSH
• zkameněliny MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Dominikánská republika MeSH
• Názvy látek
• jantar * MeSH

A new fossil genus and species of Cantharidae, Nothotytthonyxserratus Li, Biffi, Kundrata & Cai gen. et sp. nov., is reported from mid-Cretaceous Burmese amber. The new species is tentatively attributed to the extant subfamily Malthininae based on a combination of characters, including the symmetrical apical maxillary palpomeres, shortened elytra, pronotum with arched margins and well-defined borders, tibiae with apical spurs, and tarsal claws simple, although its well-developed gonostyli are atypical in Malthininae. The discovery of Nothotytthonyx also suggests a possible Gondwanan origin for Malthininae.

• Klíčová slova
• Burmese amber, Cretaceous, fossil, paleontology, soft-bodied Elateroidea, soldier beetles, systematics,
• Publikační typ
• časopisecké články MeSH

Beetles constitute the most biodiverse animal order with over 380 000 described species and possibly several million more yet unnamed. Recent phylogenomic studies have arrived at considerably incongruent topologies and widely varying estimates of divergence dates for major beetle clades. Here, we use a dataset of 68 single-copy nuclear protein-coding (NPC) genes sampling 129 out of the 193 recognized extant families as well as the first comprehensive set of fully justified fossil calibrations to recover a refined timescale of beetle evolution. Using phylogenetic methods that counter the effects of compositional and rate heterogeneity, we recover a topology congruent with morphological studies, which we use, combined with other recent phylogenomic studies, to propose several formal changes in the classification of Coleoptera: Scirtiformia and Scirtoidea sensu nov., Clambiformia ser. nov. and Clamboidea sensu nov., Rhinorhipiformia ser. nov., Byrrhoidea sensu nov., Dryopoidea stat. res., Nosodendriformia ser. nov. and Staphyliniformia sensu nov., and Erotyloidea stat. nov., Nitiduloidea stat. nov. and Cucujoidea sensu nov., alongside changes below the superfamily level. Our divergence time analyses recovered a late Carboniferous origin of Coleoptera, a late Palaeozoic origin of all modern beetle suborders and a Triassic-Jurassic origin of most extant families, while fundamental divergences within beetle phylogeny did not coincide with the hypothesis of a Cretaceous Terrestrial Revolution.

• Klíčová slova
• CAT-GTR, Coleoptera, classification, diversification, phylogenomics, substitution modelling,
• Publikační typ
• časopisecké články MeSH

We investigated and described the thoracic structures, jumping mechanism, and promesothoracic interlocking mechanism of the click beetle Campsosternus auratus (Drury) (Elateridae: Dendrometrinae). Two experiments were conducted to reveal the critical muscles and sclerites involved in the jumping mechanism. They showed that M2 and M4 are essential clicking-related muscles. The prosternal process, the prosternal rest of the mesoventrite, the mesoventral cavity, the base of the elytra, and the posterodorsal evagination of the pronotum are critical clicking-related sclerites. The destruction of any of these muscles and sclerites resulted in the loss of normal clicking and jumping ability. The mesonotum was identified as a highly specialized saddle-shaped biological spring that can store elastic energy and release it abruptly. During the jumping process of C. auratus, M2 contracts to establish and latch the clicking system, and M4 contracts to generate energy. The specialized thoracic biological springs (e.g., the prosternum and mesonotum) and elastic cuticles store and abruptly release the colossal energy, which explosively raises the beetle body in a few milliseconds. The specialized trigger muscle for the release of the clicking was not found; our study supports the theory that the triggering of the clicking is due to the building-up of tension (i.e., elastic energy) in the system.

• Klíčová slova
• 3D reconstruction, clamping, click beetles, clicking, function, locking, musculature,
• Publikační typ
• časopisecké články MeSH

Fossil bioinclusions in amber are invaluable source of information on the past evolution and diversity of various organisms, as well as on the paleoecosystems in general. The click-beetles, Elateridae, which originated and greatly diversified during the Mesozoic, are mostly known from the adpression-like fossils, and their diversity in the Cretaceous ambers is only poorly documented. In this study, we describe a new click-beetle based on an incomplete inclusion in ajkaite, an Upper Cretaceous (Santonian) amber from the Ajka Coal Formation from Hungary. We used X-ray micro-computed tomography scanning to reconstruct its morphology because it is deposited in an opaque piece of amber. Our results suggest that the newly described Ajkaelater merkli gen. et sp. nov. belongs to subfamily Elaterinae. It represents the first Mesozoic beetle reported from Hungary, and the first Mesozoic Elateridae formally described from mainland Europe. Our discovery supports an Eurasian distribution and diversification of Elaterinae already in the Cretaceous. The paleoenvironment of the Ajka Coal Formation agrees well with the presumed habitat preference of the new fossil taxon. The discovery of a presumably saproxylic click-beetle shed further light on the yet poorly known paleoecosystem of the Santonian present-day western Hungary.

• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH