To better understand insect evolution, fossils – mainly known by their wings – must be used as terminals in phylogenetic analyses. Such analyses are, however, rarely performed because of a lack of consensus on the homology of venation in insects. Researchers do not agree with the current concept on the exact number and identity of the main veins. Here, we confirm the presence, which has been in question since the early 20th century, of an independent main postcubital vein (PCu vein) between the cubital and anal veins (29 fossil and extant examined orders; > 85% of observed insects). The PCu vein corresponds to the so‐called vein 1A or first anal vein. It is easily identified by the unique shape of its bulla. It may have several branches and be partially fused with the cubital and anal veins. Once the PCu vein was identified, we reconsidered as an example the particular case of the Phasmatodea, showing that extant stick insects have a unique venation among insects, with a reduced median vein and a simple cubital vein adjacent or fused to the PCu vein. This study is a new approach towards resolving wing vein homology issues, crucial for future large‐scale phylogenetic analyses in insects combining extant and extinct taxa.
The Jurassic odonate family Steleopteridae is revised. Two new genera and species Parasteleopteron guischardi and Euparasteleopteron viohli are described. The phylogenetic affinities of this group are discussed. The Steleopteridae are excluded from the Epiproctophora and transferred into the Zygoptera (stemgroup). Euphaeopsis multinervis is redescribed and transferred to Epiproctophora: Isophlebioidea, and the genus Pseudoeuphaea with its four species is considered as a nomen dubium in Odonata incertae sedis.
The morphology of the enigmatic, Mesozoic, aquatic insect family Chresmodidae is redescribed and its phylogenetic affinities among the polyneopterous orders discussed. Study of the complete venation of both fore-and hind wings observed in some specimens from the Spanish Barremian, permit us to postulate the hypothesis that the family belongs to the Archaeorthoptera, thus to the orthopteroid lineage rather than to crown-group Phasmatodea or to the more inclusive group Holophasmatodea (sensu GRIMALDI & ENGEL, 2005). New specimens from Spain, Lebanon, Brazil, and Germany permit a new re-description of some chresmodid body structures with concomitant implications for the phylogenetic position of the family. Chresmoda neotropica n. sp. is described from the Aptian-Albian of the Crato Formation (northeast Brazil). The functional morphology proposed for some of their specialized structures suggest a new hypothesis of Chresmoda palaeobiology, and related to this some implications for the localized palaeoenvironment as well as global palaeoclimate. The problematic Sternarthron spp. from the Upper Jurassic of Solnhofen were described as probable palpigrades (Arachnida: Palpigradi), based on type material originally thought to be fossil insects. The affinities of Sternarthron HAASE, 1890 have been questioned. Our restudy of HAASE's types clearly confirmed earlier assumptions that these fossils represent nymphal specimens of chresmodids. Consequently, Sternarthron has to be considered as an invalid junior synonym of the fossil insect genera Propygolampis WEYENBERGH, 1874 and Chresmoda GERMAR, 1839.
Deciphering the timing and tempo of lineage diversification of organisms has greatly benefited from advances in Bayesian phylogenetic analyses using morphological data. Those advances, however, have not been used for termites despite a rich fossil record. Here, we estimate divergence times for living and fossil termites using the fossilized birth–death (FBD) process on a previously published morphological matrix expanded with two new fossils that we describe (see Appendices S1 and S2). Those fossils, based on soldier specimens, are the mid‐Cretaceous mastotermitid Milesitermes engeli gen. et sp. nov., and the Middle Eocene Reticulitermes grimaldii sp. nov. The latter is the oldest occurrence of a Rhinotermitidae soldier and the first termite soldier described from Baltic amber. Our dating estimates provide new stem‐ages and crown‐ages for termites, suggesting older ages than previously thought for several lineages. Importantly, crown‐Isoptera – and, therefore, eusociality – may have arisen approximately 200 Ma. We conclude with further directions to keep improving our understanding of the timing of differentiation in termites.
Archaeidae spiders have long been known to occur in Oise amber (Ypresian, early Eocene, MP7). However, they are not abundant, and have been the subject of few studies until now. Here we describe the only well-preserved, almost complete, archaeid fossil specimen. This adult male is described as Myrmecarchaea antecessor sp. nov, based on the presence of unique morphological features. The elongate petiolus and extremely long legs are characteristic of the genus Myrmecarchaea from the Middle Eocene Baltic amber. However, unique traits such as the thick, stout petiolus and the extremely elongated, posteriorly tapering cephalothorax distinguish it from the other species of Myrmecarchaea. This specimen is of high interest, as besides being a new species, it is also the first documented adult male in the genus, allowing us to describe sexual characters for the first time. Furthermore, it is the first occurrence of this genus outside Baltic amber, showing affinities between Oise and Baltic ambers, which are, otherwise, very different in their faunistic compositions.
Using a fossilized birth–death model, a new phylogeny of the superfamily Evanioidea (including ensign wasps, nightshade wasps and hatchet wasps) is proposed, with estimates of divergence times for its constitutive families and for corroborating the monophyly of Evanioidea. Additionally, our Bayesian analyses demonstrate the monophyly of †Anomopterellidae, †Othniodellithidae, †Andreneliidae, Aulacidae, Gasteruptiida and Evaniidae, whereas †Praeaulacidae and †Baissidae appear to be paraphyletic. Vectevania vetula and Hyptiogastrites electrinus are transferred to Aulacidae. We estimate the divergence time of Evanioidea to be in the Late Triassic (~203 Mya). Additionally, three new othniodellithid wasps are described and figured from mid-Cretaceous Burmese amber as the new genus Keratodellitha, with three new species: Keratodellitha anubis sp. nov., Keratodellitha basilisci sp. nov. and Keratodellitha kirin sp. nov. We also document a temporal shift in relative species richness between Ichneumonoidea and Evanioidea.
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