Lodetiella magnifica nov. gen. and nov. sp. (Insecta: Palaeodictyoptera; Permian), an extreme situation in wing morphology of palaeopterous insects

Based on published data and review of Mecynoptera splendida Handlirsch, 1904, a wing venation ground plan applicable to most taxa of the Palaeozoic superorder Palaeodictyopteroidea is proposed, where each major vein system has a simple anterior sector, and, primitively, a dichotomously branched posterior sector. Lodetiella magnifica nov. gen. and sp. is described, based on an isolated hind wing from the Salagou Formation (Middle to Late Permian; Hérault, France). The venation of Lodetiella magnifica conforms to the predicted ground plan, but differs by its simple posterior cubitus sector. This character is diagnostic of the family Calvertiellidae (Palaeodictyoptera), whose diagnosis is updated. Wing movement in flight is inferred from the peculiar wing vein organization of Lodetiella magnifica. Some ecological preferences might explain the relative rarity of calvertiellids in the fossil record.     

The earliest evidence of damselfly‐like endophytic oviposition in the fossil record

The reproductive strategy of insects of inserting eggs into plant tissue (endophytic oviposition) is known from the Late Carboniferous onwards. The earliest known ovipositional scars are large, that is up to 38 mm long, and irregular both in size and in shape, and they are not arranged in a regular pattern. Oviposition patterns resembling those of present‐day Odonata are first reported from the Late Palaeozoic. These egg cavities are generally of smaller size and have a regular oval shape. They are usually arranged in longitudinal rows or in a zigzag configuration. The most likely tracemakers were gracile damselfly‐like insects such as the Archizygoptera, a group closely related to modern Zygoptera. In this paper, the earliest evidence of endophytic oviposition resembling the ‘Coenagrionid Type’ of Odonatoptera is described. It derives from the Wettin member of the Siebigerode Formation of the Saale‐Basin in Central Germany (Upper Carboniferous, Gzhelian) and consists of about 49 elliptical scars with lengths of about 2 mm, probably deposited on a leaf of Cordaites. The arrangement of the scars in short transverse rows, their regular size and elliptical shape suggest that the tracemaker was probably a member of the extinct odonatopteran suborder Archizygoptera. If so, the tracefossil described here would be the earliest evidence for this endophytic oviposition in an ancestral group of modern Zygoptera.     

New Middle Permian palaeopteran insects from Lodève Basin in southern France (Ephemeroptera, Diaphanopterodea, Megasecoptera)

Three new palaeopteran insects are described from the Middle Permian (Guadalupian) of Salagou Formation in the Lodève Basin (South of France), viz. the diaphanopterodean Alexrasnitsyniidaefam. n., based on Alexrasnitsynia permianagen. etsp. n., the ParelmoidaePermelmoa magnificagen. etsp. n., and Lodevohymen lapeyrieigen. etsp. n. (in Megasecoptera or Diaphanopterodea, family undetermined). In addition the first record of mayflies attributed to family Syntonopteridae (Ephemeroptera) is reported. These new fossils clearly demonstrate that the present knowledge of the Permian insects remains very incomplete. They also confirm that the Lodève entomofauna was highly diverse providing links to other Permian localities and also rather unique, with several families still not recorded in other contemporaneous outcrops.     

Embryogenesis of the damselfly Euphaea yayeyamana Oguma (Insecta: Odonata: Euphaeidae), with special reference to the formation of their larval abdominal “gill‐like” appendages

The acquisition of wings in insects is the most significant subject in considering the diversification and adaptive radiation of insects, that is, the “macro‐evolution” of insects. In the discussion of the origin of insect wings, Palaeoptera has attracted particular attention in phylogenetic and evolutionary studies. In particular, Ephemeroptera have segmental gill‐structures on their abdominal segments during their nymphal stage, and these have been noted in discussions regarding their homology and/or serial homology between wings, gills and appendages. Although Odonata has received little attention in the course of these discussions, there are cases of segmental gill‐like structures on their abdomen in the two families, Euphaeidae and Polythoridae. Under such cirumstances, in this study, the embryological developmental process in Euphaea yayeyamana of Euphaeidae was observed, focusing on the formation process of the gill‐like structures. As a result, it was revealed that four of the seven pairs of gill‐like projection structures started their visible formation within the middle stages of embryonic development, and the remaining three pairs developed during the early stages of post‐embryogenesis. Some joint‐like structures existed in all of the gill‐like projections. It was revealed that muscle tissue was interposed within these protrusions and that all of the projections themselves fully articulated, and that the nervous system was extended into the protrusions. All of the gill‐like projections strongly suggested their homology with the cephalic and thoracic appendages, when we considered them with regard to their serial homology based on the topology of their formation position.     

"古翅类"系统发育关系研究进展(昆虫纲,有翅类)

古翅类的系统发育问题是六足总纲中有争议的热点问题之一。对现存古翅类(孵蝣目 蜻蜒目)与新翅类之间的系统发育关系有3种主要观点：古翅类(＝蜉蝣目 蜻蜒目) 新翅类,蜉蝣目 (蜻蜒目 新翅类),蜻蜒目 (蜉蝣目 新翅类)。第1种观点得到化石、形态和部分基因证据支持,第2种观点得到较多形态特征支持,支持第3种观点的证据较少。这一问题的解决有赖于更多昆虫种类、化石以及分子证据的发现和研究。     

New Martynoviidae from the Permian of Southern France (Lodève basin) (Insecta: Palaeoptera: Diaphanopterodea)

A new genus and two new species, Salagouneura chimaira nov. gen. and nov. sp. and Phaneroneura minuta nov. sp., together with several other specimens of uncertain affinities, are herein assigned to the family Martynoviidae. This family was previously only known from the Lower Permian of Oklahoma and Kansas (USA). The new specimens have been discovered in the Salagou Formation (Permian; Hérault, France). Stratigraphical and palaeoecological implications of the occurrence of this family in the Salagou Formation are discussed. These discoveries seem correlated with similar palaeoenvironmental conditions between the Salagou Formation and the Midco Salt Lake Formation (Oklahoma).     

A general theory of genital homologies for the Hexapoda (Pancrustacea) derived from skeletomuscular correspondences,with emphasis on the Endopterygota

No consensus exists for the homology and terminology of the male genitalia of the Hexapoda despite over a century of debate. Based on dissections and the literature, genital skeletomusculature was compared across the Hexapoda and contrasted with the Remipedia, the closest pancrustacean outgroup. The pattern of origin and insertion for extrinsic and intrinsic genitalic musculature was found to be consistent among the Ectognatha, Protura, and the Remipedia, allowing for the inference of homologies given recent phylogenomic studies. The penis of the Hexapoda is inferred to be derived from medially-fused primary gonopods (gonopore-bearing limbs), while the genitalia of the Ectognatha are inferred to include both the tenth-segmental penis and the ninth-segmental secondary gonopods, similar to the genitalia of female insects which comprise gonopods of the eighth and ninth segments. A new nomenclatural system for hexapodan genitalic musculature is presented and applied, and a general list of anatomical concepts is provided. Novel and refined homologies are proposed for all hexapodan orders, and a series of groundplans are postulated. Emphasis is placed on the Endopterygota, for which fine-grained transition series are hypothesized given observed skeletomuscular correspondences.     

Reanalyzing the Palaeoptera problem – The origin of insect flight remains obscure

The phylogenetic relationships of the winged insect lineages – mayflies (Ephemeroptera), damselflies and dragonflies (Odonata), and all other winged insects (Neoptera) – are still controversial with three hypotheses supported by different datasets: Palaeoptera, Metapterygota and Chiastomyaria. Here, we reanalyze available phylogenomic data with a focus on detecting confounding and alternative signal. In this context, we provide a framework to quantitatively evaluate and assess incongruent molecular phylogenetic signal inherent in phylogenomic datasets. Despite overall support for the Palaeoptera hypothesis, we also found considerable signal for Chiastomyaria, which is not easily detectable by standardized tree inference approaches. Analyses of the accumulation of signal across gene partitions showed that signal accumulates gradually. However, even in case signal only slightly supported one over the other hypothesis, topologies inferred from large datasets switch from statistically strongly supported Palaeoptera to strongly supported Chiastomyaria. From a morphological point of view, Palaeoptera currently appears to be the best-supported hypothesis; however, recent analyses were restricted to head characters. Phylogenetic approaches covering all organ systems including analyses of potential functional or developmental convergence are still pending so that the Palaeoptera problem has to be considered an open question in insect systematics.